00007318022024FYFALSEhttp://fasb.org/us-gaap/2024#PublicUtilitiesPropertyPlantAndEquipmentNethttp://fasb.org/us-gaap/2024#PublicUtilitiesPropertyPlantAndEquipmentNethttp://fasb.org/us-gaap/2024#OtherAssetsNoncurrenthttp://fasb.org/us-gaap/2024#OtherAssetsNoncurrenthttp://fasb.org/us-gaap/2024#LongTermDebtAndCapitalLeaseObligationsCurrenthttp://fasb.org/us-gaap/2024#LongTermDebtAndCapitalLeaseObligationsCurrenthttp://fasb.org/us-gaap/2024#OtherLiabilitiesCurrenthttp://fasb.org/us-gaap/2024#OtherLiabilitiesCurrenthttp://fasb.org/us-gaap/2024#LongTermDebtAndCapitalLeaseObligationshttp://fasb.org/us-gaap/2024#LongTermDebtAndCapitalLeaseObligationshttp://fasb.org/us-gaap/2024#OtherLiabilitiesNoncurrenthttp://fasb.org/us-gaap/2024#OtherLiabilitiesNoncurrentP3Yhttp://fasb.org/us-gaap/2024#OtherNonoperatingIncomeExpensehttp://fasb.org/us-gaap/2024#OtherNonoperatingIncomeExpensehttp://fasb.org/us-gaap/2024#OtherNonoperatingIncomeExpensehttp://fasb.org/us-gaap/2024#OtherNonoperatingIncomeExpensehttp://fasb.org/us-gaap/2024#OtherNonoperatingIncomeExpensehttp://fasb.org/us-gaap/2024#OtherNonoperatingIncomeExpensehttp://fasb.org/us-gaap/2024#OtherNonoperatingIncomeExpensehttp://fasb.org/us-gaap/2024#OtherNonoperatingIncomeExpensehttp://fasb.org/us-gaap/2024#OtherNonoperatingIncomeExpenseP2Yiso4217:USDxbrli:sharesiso4217:USDxbrli:sharesato:customerato:regulatedDistributionDivisionato:facilityutr:miato:planxbrli:pureato:segmentato:stateato:serviceCenterato:creditFacilityato:incidentato:fatalityutr:MMcfiso4217:USDutr:Mcf00007318022023-10-012024-09-3000007318022024-03-3100007318022024-11-1400007318022024-09-3000007318022023-09-300000731802us-gaap:OperatingSegmentsMemberato:DistributionSegmentMember2023-10-012024-09-300000731802us-gaap:OperatingSegmentsMemberato:DistributionSegmentMember2022-10-012023-09-300000731802us-gaap:OperatingSegmentsMemberato:DistributionSegmentMember2021-10-012022-09-300000731802us-gaap:OperatingSegmentsMemberato:PipelineandStorageSegmentMember2023-10-012024-09-300000731802us-gaap:OperatingSegmentsMemberato:PipelineandStorageSegmentMember2022-10-012023-09-300000731802us-gaap:OperatingSegmentsMemberato:PipelineandStorageSegmentMember2021-10-012022-09-300000731802us-gaap:IntersegmentEliminationMember2023-10-012024-09-300000731802us-gaap:IntersegmentEliminationMember2022-10-012023-09-300000731802us-gaap:IntersegmentEliminationMember2021-10-012022-09-3000007318022022-10-012023-09-3000007318022021-10-012022-09-300000731802us-gaap:CommonStockMember2021-09-300000731802us-gaap:AdditionalPaidInCapitalMember2021-09-300000731802us-gaap:AccumulatedOtherComprehensiveIncomeMember2021-09-300000731802us-gaap:RetainedEarningsMember2021-09-3000007318022021-09-300000731802us-gaap:RetainedEarningsMember2021-10-012022-09-300000731802us-gaap:AccumulatedOtherComprehensiveIncomeMember2021-10-012022-09-300000731802us-gaap:CommonStockMember2021-10-012022-09-300000731802us-gaap:AdditionalPaidInCapitalMember2021-10-012022-09-300000731802us-gaap:CommonStockMember2022-09-300000731802us-gaap:AdditionalPaidInCapitalMember2022-09-300000731802us-gaap:AccumulatedOtherComprehensiveIncomeMember2022-09-300000731802us-gaap:RetainedEarningsMember2022-09-3000007318022022-09-300000731802us-gaap:RetainedEarningsMember2022-10-012023-09-300000731802us-gaap:AccumulatedOtherComprehensiveIncomeMember2022-10-012023-09-300000731802us-gaap:CommonStockMember2022-10-012023-09-300000731802us-gaap:AdditionalPaidInCapitalMember2022-10-012023-09-300000731802us-gaap:CommonStockMember2023-09-300000731802us-gaap:AdditionalPaidInCapitalMember2023-09-300000731802us-gaap:AccumulatedOtherComprehensiveIncomeMember2023-09-300000731802us-gaap:RetainedEarningsMember2023-09-300000731802us-gaap:RetainedEarningsMember2023-10-012024-09-300000731802us-gaap:AccumulatedOtherComprehensiveIncomeMember2023-10-012024-09-300000731802us-gaap:CommonStockMember2023-10-012024-09-300000731802us-gaap:AdditionalPaidInCapitalMember2023-10-012024-09-300000731802us-gaap:CommonStockMember2024-09-300000731802us-gaap:AdditionalPaidInCapitalMember2024-09-300000731802us-gaap:AccumulatedOtherComprehensiveIncomeMember2024-09-300000731802us-gaap:RetainedEarningsMember2024-09-300000731802stpr:LAato:PipelineandStorageSegmentMember2024-09-300000731802ato:PipelineandStorageSegmentMember2023-10-012024-09-300000731802ato:PipelineandStorageSegmentMember2023-11-302023-11-300000731802ato:PipelineandStorageSegmentMember2023-12-012023-12-310000731802us-gaap:PensionAndOtherPostretirementPlansCostsMember2024-09-300000731802us-gaap:PensionAndOtherPostretirementPlansCostsMember2023-09-300000731802ato:InfrastructureMechanismsMember2024-09-300000731802ato:InfrastructureMechanismsMember2023-09-300000731802us-gaap:StormCostsMember2024-09-300000731802us-gaap:StormCostsMember2023-09-300000731802us-gaap:DeferredFuelCostsMember2024-09-300000731802us-gaap:DeferredFuelCostsMember2023-09-300000731802us-gaap:DeferredIncomeTaxChargesMember2024-09-300000731802us-gaap:DeferredIncomeTaxChargesMember2023-09-300000731802us-gaap:LossOnReacquiredDebtMember2024-09-300000731802us-gaap:LossOnReacquiredDebtMember2023-09-300000731802us-gaap:DeferredProjectCostsMember2024-09-300000731802us-gaap:DeferredProjectCostsMember2023-09-300000731802ato:APTAnnualSystemSafetyAndIntegrityRiderMember2024-09-300000731802ato:APTAnnualSystemSafetyAndIntegrityRiderMember2023-09-300000731802us-gaap:OtherRegulatoryAssetsLiabilitiesMember2024-09-300000731802us-gaap:OtherRegulatoryAssetsLiabilitiesMember2023-09-300000731802us-gaap:DeferredIncomeTaxChargesMember2024-09-300000731802us-gaap:DeferredIncomeTaxChargesMember2023-09-300000731802us-gaap:RemovalCostsMember2024-09-300000731802us-gaap:RemovalCostsMember2023-09-300000731802us-gaap:DeferredFuelCostsMember2024-09-300000731802us-gaap:DeferredFuelCostsMember2023-09-300000731802ato:RegulatoryClauseRevenuesOverRecoveredMember2024-09-300000731802ato:RegulatoryClauseRevenuesOverRecoveredMember2023-09-300000731802us-gaap:PensionAndOtherPostretirementPlansCostsMember2024-09-300000731802us-gaap:PensionAndOtherPostretirementPlansCostsMember2023-09-300000731802us-gaap:OtherRegulatoryAssetsLiabilitiesMember2024-09-300000731802us-gaap:OtherRegulatoryAssetsLiabilitiesMember2023-09-300000731802stpr:TXato:WinterStormUriMember2021-09-300000731802stpr:TXus-gaap:AssetRecoverableGasCostsMemberato:WinterStormUriMember2023-03-310000731802stpr:TXus-gaap:AssetRecoverableGasCostsMemberato:WinterStormUriMembersrt:MinimumMember2023-03-012023-03-310000731802stpr:TXus-gaap:AssetRecoverableGasCostsMemberato:WinterStormUriMembersrt:MaximumMember2023-03-012023-03-310000731802stpr:TXus-gaap:AssetRecoverableGasCostsMemberato:WinterStormUriMember2023-03-012023-03-310000731802stpr:TXus-gaap:StormCostsMemberato:WinterStormUriMember2022-09-012022-09-010000731802stpr:TXus-gaap:StormCostsMemberato:WinterStormUriMember2023-10-012024-09-300000731802stpr:TXus-gaap:StormCostsMemberato:WinterStormUriMember2024-09-300000731802stpr:TXus-gaap:StormCostsMemberus-gaap:OtherCurrentAssetsMemberato:WinterStormUriMember2024-09-300000731802stpr:TXus-gaap:StormCostsMemberus-gaap:OtherNoncurrentAssetsMemberato:WinterStormUriMember2024-09-300000731802ato:DistributionSegmentMember2023-10-012024-09-300000731802us-gaap:IntersegmentEliminationMemberato:DistributionSegmentMember2023-10-012024-09-300000731802us-gaap:IntersegmentEliminationMemberato:PipelineandStorageSegmentMember2023-10-012024-09-300000731802ato:DistributionSegmentMember2022-10-012023-09-300000731802ato:PipelineandStorageSegmentMember2022-10-012023-09-300000731802us-gaap:IntersegmentEliminationMemberato:DistributionSegmentMember2022-10-012023-09-300000731802us-gaap:IntersegmentEliminationMemberato:PipelineandStorageSegmentMember2022-10-012023-09-300000731802ato:DistributionSegmentMember2021-10-012022-09-300000731802ato:PipelineandStorageSegmentMember2021-10-012022-09-300000731802us-gaap:IntersegmentEliminationMemberato:DistributionSegmentMember2021-10-012022-09-300000731802us-gaap:IntersegmentEliminationMemberato:PipelineandStorageSegmentMember2021-10-012022-09-300000731802ato:ResidentialCustomersMemberus-gaap:NaturalGasUsRegulatedMemberato:DistributionSegmentMember2023-10-012024-09-300000731802ato:ResidentialCustomersMemberus-gaap:NaturalGasUsRegulatedMemberato:DistributionSegmentMember2022-10-012023-09-300000731802ato:ResidentialCustomersMemberus-gaap:NaturalGasUsRegulatedMemberato:DistributionSegmentMember2021-10-012022-09-300000731802ato:CommercialCustomersMemberus-gaap:NaturalGasUsRegulatedMemberato:DistributionSegmentMember2023-10-012024-09-300000731802ato:CommercialCustomersMemberus-gaap:NaturalGasUsRegulatedMemberato:DistributionSegmentMember2022-10-012023-09-300000731802ato:CommercialCustomersMemberus-gaap:NaturalGasUsRegulatedMemberato:DistributionSegmentMember2021-10-012022-09-300000731802ato:IndustrialCustomersMemberus-gaap:NaturalGasUsRegulatedMemberato:DistributionSegmentMember2023-10-012024-09-300000731802ato:IndustrialCustomersMemberus-gaap:NaturalGasUsRegulatedMemberato:DistributionSegmentMember2022-10-012023-09-300000731802ato:IndustrialCustomersMemberus-gaap:NaturalGasUsRegulatedMemberato:DistributionSegmentMember2021-10-012022-09-300000731802ato:PublicAuthorityandOtherCustomersMemberus-gaap:NaturalGasUsRegulatedMemberato:DistributionSegmentMember2023-10-012024-09-300000731802ato:PublicAuthorityandOtherCustomersMemberus-gaap:NaturalGasUsRegulatedMemberato:DistributionSegmentMember2022-10-012023-09-300000731802ato:PublicAuthorityandOtherCustomersMemberus-gaap:NaturalGasUsRegulatedMemberato:DistributionSegmentMember2021-10-012022-09-300000731802us-gaap:NaturalGasUsRegulatedMemberato:DistributionSegmentMember2023-10-012024-09-300000731802us-gaap:NaturalGasUsRegulatedMemberato:DistributionSegmentMember2022-10-012023-09-300000731802us-gaap:NaturalGasUsRegulatedMemberato:DistributionSegmentMember2021-10-012022-09-300000731802us-gaap:NaturalGasGatheringTransportationMarketingAndProcessingMemberato:DistributionSegmentMember2023-10-012024-09-300000731802us-gaap:NaturalGasGatheringTransportationMarketingAndProcessingMemberato:DistributionSegmentMember2022-10-012023-09-300000731802us-gaap:NaturalGasGatheringTransportationMarketingAndProcessingMemberato:DistributionSegmentMember2021-10-012022-09-300000731802ato:NaturalGasOtherMemberato:DistributionSegmentMember2023-10-012024-09-300000731802ato:NaturalGasOtherMemberato:DistributionSegmentMember2022-10-012023-09-300000731802ato:NaturalGasOtherMemberato:DistributionSegmentMember2021-10-012022-09-300000731802us-gaap:OperatingSegmentsMemberato:DistributionSegmentMember2024-09-300000731802us-gaap:OperatingSegmentsMemberato:PipelineandStorageSegmentMember2024-09-300000731802us-gaap:IntersegmentEliminationMember2024-09-300000731802us-gaap:OperatingSegmentsMemberato:DistributionSegmentMember2023-09-300000731802us-gaap:OperatingSegmentsMemberato:PipelineandStorageSegmentMember2023-09-300000731802us-gaap:IntersegmentEliminationMember2023-09-300000731802ato:ResidentialCustomersMemberus-gaap:OperatingSegmentsMemberato:GassalesrevenueMemberato:DistributionSegmentMember2023-10-012024-09-300000731802ato:ResidentialCustomersMemberus-gaap:OperatingSegmentsMemberato:GassalesrevenueMemberato:PipelineandStorageSegmentMember2023-10-012024-09-300000731802ato:CommercialCustomersMemberus-gaap:OperatingSegmentsMemberato:GassalesrevenueMemberato:DistributionSegmentMember2023-10-012024-09-300000731802ato:CommercialCustomersMemberus-gaap:OperatingSegmentsMemberato:GassalesrevenueMemberato:PipelineandStorageSegmentMember2023-10-012024-09-300000731802ato:IndustrialCustomersMemberus-gaap:OperatingSegmentsMemberato:GassalesrevenueMemberato:DistributionSegmentMember2023-10-012024-09-300000731802ato:IndustrialCustomersMemberus-gaap:OperatingSegmentsMemberato:GassalesrevenueMemberato:PipelineandStorageSegmentMember2023-10-012024-09-300000731802ato:PublicAuthorityandOtherCustomersMemberus-gaap:OperatingSegmentsMemberato:GassalesrevenueMemberato:DistributionSegmentMember2023-10-012024-09-300000731802ato:PublicAuthorityandOtherCustomersMemberus-gaap:OperatingSegmentsMemberato:GassalesrevenueMemberato:PipelineandStorageSegmentMember2023-10-012024-09-300000731802us-gaap:OperatingSegmentsMemberato:GassalesrevenueMemberato:DistributionSegmentMember2023-10-012024-09-300000731802us-gaap:OperatingSegmentsMemberato:GassalesrevenueMemberato:PipelineandStorageSegmentMember2023-10-012024-09-300000731802us-gaap:OperatingSegmentsMemberato:TransportationrevenueMemberato:DistributionSegmentMember2023-10-012024-09-300000731802us-gaap:OperatingSegmentsMemberato:TransportationrevenueMemberato:PipelineandStorageSegmentMember2023-10-012024-09-300000731802us-gaap:OperatingSegmentsMemberato:MiscellaneousrevenueMemberato:DistributionSegmentMember2023-10-012024-09-300000731802us-gaap:OperatingSegmentsMemberato:MiscellaneousrevenueMemberato:PipelineandStorageSegmentMember2023-10-012024-09-300000731802ato:ResidentialCustomersMemberus-gaap:OperatingSegmentsMemberato:GassalesrevenueMemberato:DistributionSegmentMember2022-10-012023-09-300000731802ato:ResidentialCustomersMemberus-gaap:OperatingSegmentsMemberato:GassalesrevenueMemberato:PipelineandStorageSegmentMember2022-10-012023-09-300000731802ato:CommercialCustomersMemberus-gaap:OperatingSegmentsMemberato:GassalesrevenueMemberato:DistributionSegmentMember2022-10-012023-09-300000731802ato:CommercialCustomersMemberus-gaap:OperatingSegmentsMemberato:GassalesrevenueMemberato:PipelineandStorageSegmentMember2022-10-012023-09-300000731802ato:IndustrialCustomersMemberus-gaap:OperatingSegmentsMemberato:GassalesrevenueMemberato:DistributionSegmentMember2022-10-012023-09-300000731802ato:IndustrialCustomersMemberus-gaap:OperatingSegmentsMemberato:GassalesrevenueMemberato:PipelineandStorageSegmentMember2022-10-012023-09-300000731802ato:PublicAuthorityandOtherCustomersMemberus-gaap:OperatingSegmentsMemberato:GassalesrevenueMemberato:DistributionSegmentMember2022-10-012023-09-300000731802ato:PublicAuthorityandOtherCustomersMemberus-gaap:OperatingSegmentsMemberato:GassalesrevenueMemberato:PipelineandStorageSegmentMember2022-10-012023-09-300000731802us-gaap:OperatingSegmentsMemberato:GassalesrevenueMemberato:DistributionSegmentMember2022-10-012023-09-300000731802us-gaap:OperatingSegmentsMemberato:GassalesrevenueMemberato:PipelineandStorageSegmentMember2022-10-012023-09-300000731802us-gaap:OperatingSegmentsMemberato:TransportationrevenueMemberato:DistributionSegmentMember2022-10-012023-09-300000731802us-gaap:OperatingSegmentsMemberato:TransportationrevenueMemberato:PipelineandStorageSegmentMember2022-10-012023-09-300000731802us-gaap:OperatingSegmentsMemberato:MiscellaneousrevenueMemberato:DistributionSegmentMember2022-10-012023-09-300000731802us-gaap:OperatingSegmentsMemberato:MiscellaneousrevenueMemberato:PipelineandStorageSegmentMember2022-10-012023-09-300000731802ato:ResidentialCustomersMemberus-gaap:OperatingSegmentsMemberato:GassalesrevenueMemberato:DistributionSegmentMember2021-10-012022-09-300000731802ato:ResidentialCustomersMemberus-gaap:OperatingSegmentsMemberato:GassalesrevenueMemberato:PipelineandStorageSegmentMember2021-10-012022-09-300000731802ato:CommercialCustomersMemberus-gaap:OperatingSegmentsMemberato:GassalesrevenueMemberato:DistributionSegmentMember2021-10-012022-09-300000731802ato:CommercialCustomersMemberus-gaap:OperatingSegmentsMemberato:GassalesrevenueMemberato:PipelineandStorageSegmentMember2021-10-012022-09-300000731802ato:IndustrialCustomersMemberus-gaap:OperatingSegmentsMemberato:GassalesrevenueMemberato:DistributionSegmentMember2021-10-012022-09-300000731802ato:IndustrialCustomersMemberus-gaap:OperatingSegmentsMemberato:GassalesrevenueMemberato:PipelineandStorageSegmentMember2021-10-012022-09-300000731802ato:PublicAuthorityandOtherCustomersMemberus-gaap:OperatingSegmentsMemberato:GassalesrevenueMemberato:DistributionSegmentMember2021-10-012022-09-300000731802ato:PublicAuthorityandOtherCustomersMemberus-gaap:OperatingSegmentsMemberato:GassalesrevenueMemberato:PipelineandStorageSegmentMember2021-10-012022-09-300000731802us-gaap:OperatingSegmentsMemberato:GassalesrevenueMemberato:DistributionSegmentMember2021-10-012022-09-300000731802us-gaap:OperatingSegmentsMemberato:GassalesrevenueMemberato:PipelineandStorageSegmentMember2021-10-012022-09-300000731802us-gaap:OperatingSegmentsMemberato:TransportationrevenueMemberato:DistributionSegmentMember2021-10-012022-09-300000731802us-gaap:OperatingSegmentsMemberato:TransportationrevenueMemberato:PipelineandStorageSegmentMember2021-10-012022-09-300000731802us-gaap:OperatingSegmentsMemberato:MiscellaneousrevenueMemberato:DistributionSegmentMember2021-10-012022-09-300000731802us-gaap:OperatingSegmentsMemberato:MiscellaneousrevenueMemberato:PipelineandStorageSegmentMember2021-10-012022-09-300000731802ato:MississippiPublicServiceCommissionMember2023-12-310000731802ato:MississippiPublicServiceCommissionMember2023-11-300000731802ato:MississippiPublicServiceCommissionMember2023-10-012023-12-310000731802ato:MississippiPublicServiceCommissionMember2022-04-012024-09-300000731802ato:MississippiPublicServiceCommissionMember2023-10-012024-09-300000731802ato:Unsecured300SeniorNotesDueJune2027Member2024-09-300000731802ato:Unsecured300SeniorNotesDueJune2027Member2023-09-300000731802ato:Unsecured2625SeniorNotesDueSeptember2029Member2024-09-300000731802ato:Unsecured2625SeniorNotesDueSeptember2029Member2023-09-300000731802ato:Unsecured150SeniorNotesDueJanuary2031Member2024-09-300000731802ato:Unsecured150SeniorNotesDueJanuary2031Member2023-09-300000731802ato:Unsecured545SeniorNotesDueOctober2032Member2024-09-300000731802ato:Unsecured545SeniorNotesDueOctober2032Member2023-09-300000731802ato:Unsecured590SeniorNotesDueOctober2033Member2024-09-300000731802ato:Unsecured590SeniorNotesDueOctober2033Member2023-09-300000731802ato:Unsecured595SeniorNotesDueOctober2034Member2024-09-300000731802ato:Unsecured595SeniorNotesDueOctober2034Member2023-09-300000731802ato:Unsecured550SeniorNotesDueJune2041Member2024-09-300000731802ato:Unsecured550SeniorNotesDueJune2041Member2023-09-300000731802ato:Unsecured415SeniorNotesDueJanuary2043Member2024-09-300000731802ato:Unsecured415SeniorNotesDueJanuary2043Member2023-09-300000731802ato:Unsecured4125SeniorNotesDueOctober2044Member2024-09-300000731802ato:Unsecured4125SeniorNotesDueOctober2044Member2023-09-300000731802ato:Unsecured430SeniorNotesDueOctober2048Member2024-09-300000731802ato:Unsecured430SeniorNotesDueOctober2048Member2023-09-300000731802ato:Unsecured4125SeniorNotesDueMarch2049Member2024-09-300000731802ato:Unsecured4125SeniorNotesDueMarch2049Member2023-09-300000731802ato:Unsecured3375SeniorNotesDueSeptember2049Member2024-09-300000731802ato:Unsecured3375SeniorNotesDueSeptember2049Member2023-09-300000731802ato:Unsecured285SeniorNotesDueFebruary2052Member2024-09-300000731802ato:Unsecured285SeniorNotesDueFebruary2052Member2023-09-300000731802ato:Unsecured575SeniorNotesDueOctober2052Member2024-09-300000731802ato:Unsecured575SeniorNotesDueOctober2052Member2023-09-300000731802ato:Unsecured620SeniorNotesDueOctober2053Member2024-09-300000731802ato:Unsecured620SeniorNotesDueOctober2053Member2023-09-300000731802ato:MediumTermNoteSeriesA19951667DueDecember2025Member2024-09-300000731802ato:MediumTermNoteSeriesA19951667DueDecember2025Member2023-09-300000731802ato:Unsecured675DebenturesDueJuly2028Member2024-09-300000731802ato:Unsecured675DebenturesDueJuly2028Member2023-09-300000731802ato:Unsecured5.00SeniorNotesDueOctober2054Memberus-gaap:SeniorNotesMemberus-gaap:SubsequentEventMember2024-10-010000731802ato:Unsecured5.00SeniorNotesDueOctober2054Memberus-gaap:SeniorNotesMemberus-gaap:SubsequentEventMember2024-10-012024-10-010000731802us-gaap:SeniorNotesMember2024-09-012024-09-300000731802ato:Unsecured590SeniorNotesDueOctober2033Memberus-gaap:SeniorNotesMember2024-06-210000731802ato:Unsecured590SeniorNotesDueOctober2033Memberus-gaap:SeniorNotesMember2024-06-212024-06-210000731802ato:Unsecured620SeniorNotesDueOctober2053Memberus-gaap:SeniorNotesMember2023-10-100000731802ato:Unsecured590SeniorNotesDueOctober2033Memberus-gaap:SeniorNotesMember2023-10-100000731802ato:UnsecuredSeniorNotesDue2033AndUnsecuredSeniorNotesDue2053Memberus-gaap:SeniorNotesMember2023-10-102023-10-100000731802us-gaap:SeniorNotesMember2023-09-012023-09-300000731802ato:Unsecured575SeniorNotesDueOctober2052Memberus-gaap:SeniorNotesMember2022-10-030000731802ato:Unsecured545SeniorNotesDueOctober2032Memberus-gaap:SeniorNotesMember2022-10-030000731802ato:UnsecuredSeniorNotesDue2032AndUnsecuredSeniorNotesDue2052Memberus-gaap:SeniorNotesMember2022-10-032022-10-030000731802ato:UnsecuredSeniorNotesDue2052Memberus-gaap:SeniorNotesMember2022-09-300000731802us-gaap:SeniorNotesMember2022-09-012022-09-3000007318022021-02-012021-02-280000731802us-gaap:SeniorNotesMember2021-03-310000731802ato:UnsecuredSeniorTermLoanDue2023Memberus-gaap:LineOfCreditMemberus-gaap:UnsecuredDebtMember2023-03-030000731802us-gaap:SeniorNotesMember2023-03-032023-03-030000731802stpr:TXus-gaap:AssetRecoverableGasCostsMemberato:WinterStormUriMember2023-03-232023-03-230000731802ato:FiveYearUnsecuredRevolvingCreditAgreementMaturingOnMarch282029Memberus-gaap:CommercialPaperMember2024-09-300000731802ato:FiveYearUnsecuredRevolvingCreditAgreementMaturingOnMarch282029Memberus-gaap:RevolvingCreditFacilityMember2024-09-300000731802ato:FiveYearUnsecuredRevolvingCreditAgreementMemberus-gaap:CommercialPaperMember2024-03-272024-03-270000731802ato:FiveYearUnsecuredRevolvingCreditAgreementMemberus-gaap:CommercialPaperMember2024-03-270000731802ato:FiveYearUnsecuredRevolvingCreditAgreementMaturingOnMarch282029Memberus-gaap:CommercialPaperMember2024-03-282024-03-280000731802ato:FiveYearUnsecuredRevolvingCreditAgreementMaturingOnMarch282029Memberus-gaap:CommercialPaperMember2024-03-280000731802ato:FiveYearUnsecuredRevolvingCreditAgreementMaturingOnMarch282029Memberus-gaap:BaseRateMembersrt:MinimumMember2023-10-012024-09-300000731802ato:FiveYearUnsecuredRevolvingCreditAgreementMaturingOnMarch282029Memberus-gaap:BaseRateMembersrt:MaximumMember2023-10-012024-09-300000731802ato:FiveYearUnsecuredRevolvingCreditAgreementMaturingOnMarch282029Memberus-gaap:SecuredOvernightFinancingRateSofrMembersrt:MinimumMember2023-10-012024-09-300000731802ato:FiveYearUnsecuredRevolvingCreditAgreementMaturingOnMarch282029Memberus-gaap:SecuredOvernightFinancingRateSofrMembersrt:MaximumMember2023-10-012024-09-300000731802ato:FiveYearUnsecuredRevolvingCreditAgreementMember2024-09-300000731802ato:FiveYearUnsecuredRevolvingCreditAgreementMember2023-09-300000731802ato:A900MillionRevolvingCreditFacilityMemberus-gaap:RevolvingCreditFacilityMember2024-03-270000731802ato:A900MillionRevolvingCreditFacilityMemberus-gaap:RevolvingCreditFacilityMember2024-03-272024-03-270000731802ato:A1.5BillionRevolvingCreditFacilityMemberus-gaap:RevolvingCreditFacilityMember2024-03-280000731802ato:A1.5BillionRevolvingCreditFacilityMemberus-gaap:RevolvingCreditFacilityMember2024-03-282024-03-280000731802ato:A1.5BillionRevolvingCreditFacilityMemberus-gaap:RevolvingCreditFacilityMemberus-gaap:BaseRateMembersrt:MinimumMember2023-10-012024-09-300000731802ato:A1.5BillionRevolvingCreditFacilityMemberus-gaap:RevolvingCreditFacilityMemberus-gaap:BaseRateMembersrt:MaximumMember2023-10-012024-09-300000731802ato:A1.5BillionRevolvingCreditFacilityMemberus-gaap:RevolvingCreditFacilityMemberus-gaap:SecuredOvernightFinancingRateSofrMembersrt:MinimumMember2023-10-012024-09-300000731802ato:A1.5BillionRevolvingCreditFacilityMemberus-gaap:RevolvingCreditFacilityMemberus-gaap:SecuredOvernightFinancingRateSofrMembersrt:MaximumMember2023-10-012024-09-300000731802ato:A1.5BillionRevolvingCreditFacilityMemberus-gaap:RevolvingCreditFacilityMember2023-09-300000731802ato:A900MillionRevolvingCreditFacilityMemberus-gaap:RevolvingCreditFacilityMember2023-09-300000731802ato:A1.5BillionRevolvingCreditFacilityMemberus-gaap:RevolvingCreditFacilityMember2024-09-300000731802ato:A900MillionRevolvingCreditFacilityMemberus-gaap:RevolvingCreditFacilityMember2024-09-300000731802ato:A50MillionBankLoanAgreementMemberus-gaap:LineOfCreditMember2024-04-010000731802ato:A50MillionBankLoanAgreementMemberus-gaap:LineOfCreditMember2024-04-012024-04-010000731802ato:A50MillionBankLoanAgreementMemberus-gaap:LineOfCreditMember2023-09-300000731802ato:A50MillionBankLoanAgreementMemberus-gaap:LineOfCreditMember2024-09-300000731802ato:A50MillionRevolvingCreditFacilityMemberus-gaap:RevolvingCreditFacilityMember2024-03-310000731802ato:A50MillionRevolvingCreditFacilityMemberus-gaap:RevolvingCreditFacilityMember2024-03-312024-03-310000731802ato:A50MillionRevolvingCreditFacilityMemberus-gaap:RevolvingCreditFacilityMember2024-09-300000731802srt:MinimumMember2024-09-300000731802srt:MaximumMember2024-09-300000731802ato:ShelfRegistrationStatementMember2023-03-310000731802us-gaap:SubsequentEventMemberato:ShelfRegistrationStatementMember2024-11-180000731802ato:AtTheMarketMember2024-05-080000731802ato:AtTheMarketMember2023-10-012024-09-300000731802ato:AtTheMarketMember2024-09-300000731802ato:ForwardSalesEquityAgreementMaturingQuarterEndedJune302025Member2024-09-300000731802ato:ForwardSalesEquityAgreementMaturingQuarterEndedJune302025Member2023-10-012024-09-300000731802ato:ForwardSalesEquityAgreementMaturingQuarterEndedSeptember302025Member2024-09-300000731802ato:ForwardSalesEquityAgreementMaturingQuarterEndedSeptember302025Member2023-10-012024-09-300000731802ato:ForwardSalesEquityAgreementMaturingQuarterEndedDecember312025Member2024-09-300000731802ato:ForwardSalesEquityAgreementMaturingQuarterEndedDecember312025Member2023-10-012024-09-300000731802ato:ForwardSalesEquityAgreementMaturingQuarterEndedMarch312026Member2024-09-300000731802ato:ForwardSalesEquityAgreementMaturingQuarterEndedMarch312026Member2023-10-012024-09-300000731802ato:ForwardSalesEquityAgreementMaturingQuarterEndedJune302026Member2024-09-300000731802ato:ForwardSalesEquityAgreementMaturingQuarterEndedJune302026Member2023-10-012024-09-300000731802us-gaap:AccumulatedNetUnrealizedInvestmentGainLossMember2023-09-300000731802us-gaap:AccumulatedGainLossNetCashFlowHedgeParentMember2023-09-300000731802us-gaap:AccumulatedNetUnrealizedInvestmentGainLossMember2023-10-012024-09-300000731802us-gaap:AccumulatedGainLossNetCashFlowHedgeParentMember2023-10-012024-09-300000731802us-gaap:AccumulatedNetUnrealizedInvestmentGainLossMember2024-09-300000731802us-gaap:AccumulatedGainLossNetCashFlowHedgeParentMember2024-09-300000731802us-gaap:AccumulatedNetUnrealizedInvestmentGainLossMember2022-09-300000731802us-gaap:AccumulatedGainLossNetCashFlowHedgeParentMember2022-09-300000731802us-gaap:AccumulatedNetUnrealizedInvestmentGainLossMember2022-10-012023-09-300000731802us-gaap:AccumulatedGainLossNetCashFlowHedgeParentMember2022-10-012023-09-300000731802ato:Series2023ASeniorSecuredSecuritizedUtilityTariffBondsDueMarch2033Memberus-gaap:VariableInterestEntityPrimaryBeneficiaryMemberus-gaap:SeniorNotesMember2023-06-300000731802ato:Series2023ASeniorSecuredSecuritizedUtilityTariffBondsDueMarch2033Memberus-gaap:VariableInterestEntityPrimaryBeneficiaryMemberus-gaap:SeniorNotesMember2023-06-012023-06-300000731802ato:SecuritizedUtilityTariffPropertyMemberus-gaap:VariableInterestEntityPrimaryBeneficiaryMember2023-06-012023-06-300000731802ato:SecuritizedUtilityTariffPropertyMemberus-gaap:VariableInterestEntityPrimaryBeneficiaryMember2023-06-300000731802ato:SecuritizedUtilityTariffPropertyMemberus-gaap:VariableInterestEntityPrimaryBeneficiaryMember2024-09-300000731802us-gaap:VariableInterestEntityPrimaryBeneficiaryMember2024-09-300000731802us-gaap:VariableInterestEntityPrimaryBeneficiaryMember2023-09-300000731802us-gaap:VariableInterestEntityPrimaryBeneficiaryMember2023-10-012024-09-300000731802us-gaap:VariableInterestEntityPrimaryBeneficiaryMember2022-10-012023-09-300000731802ato:Series2023ASeniorSecuredSecuritizedUtilityTariffBondsDueMarch2033Memberus-gaap:VariableInterestEntityPrimaryBeneficiaryMemberus-gaap:SeniorNotesMember2024-09-300000731802us-gaap:PensionPlansDefinedBenefitMemberato:UnrecognizedPriorServiceCreditMember2024-09-300000731802us-gaap:SupplementalEmployeeRetirementPlanDefinedBenefitMemberato:UnrecognizedPriorServiceCreditMember2024-09-300000731802us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMemberato:UnrecognizedPriorServiceCreditMember2024-09-300000731802ato:UnrecognizedPriorServiceCreditMember2024-09-300000731802us-gaap:PensionPlansDefinedBenefitMemberato:UnrecognizedActuarialGainLossMember2024-09-300000731802us-gaap:SupplementalEmployeeRetirementPlanDefinedBenefitMemberato:UnrecognizedActuarialGainLossMember2024-09-300000731802us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMemberato:UnrecognizedActuarialGainLossMember2024-09-300000731802ato:UnrecognizedActuarialGainLossMember2024-09-300000731802us-gaap:PensionPlansDefinedBenefitMemberato:TotalUnrecognizedinNetPeriodicPensionCostMember2024-09-300000731802us-gaap:SupplementalEmployeeRetirementPlanDefinedBenefitMemberato:TotalUnrecognizedinNetPeriodicPensionCostMember2024-09-300000731802us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMemberato:TotalUnrecognizedinNetPeriodicPensionCostMember2024-09-300000731802us-gaap:PensionAndOtherPostretirementPlansCostsMemberato:TotalUnrecognizedinNetPeriodicPensionCostMember2024-09-300000731802us-gaap:PensionPlansDefinedBenefitMemberato:UnrecognizedPriorServiceCreditMember2023-09-300000731802us-gaap:SupplementalEmployeeRetirementPlanDefinedBenefitMemberato:UnrecognizedPriorServiceCreditMember2023-09-300000731802us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMemberato:UnrecognizedPriorServiceCreditMember2023-09-300000731802ato:UnrecognizedPriorServiceCreditMember2023-09-300000731802us-gaap:PensionPlansDefinedBenefitMemberato:UnrecognizedActuarialGainLossMember2023-09-300000731802us-gaap:SupplementalEmployeeRetirementPlanDefinedBenefitMemberato:UnrecognizedActuarialGainLossMember2023-09-300000731802us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMemberato:UnrecognizedActuarialGainLossMember2023-09-300000731802ato:UnrecognizedActuarialGainLossMember2023-09-300000731802us-gaap:PensionPlansDefinedBenefitMemberato:TotalUnrecognizedinNetPeriodicPensionCostMember2023-09-300000731802us-gaap:SupplementalEmployeeRetirementPlanDefinedBenefitMemberato:TotalUnrecognizedinNetPeriodicPensionCostMember2023-09-300000731802us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMemberato:TotalUnrecognizedinNetPeriodicPensionCostMember2023-09-300000731802us-gaap:PensionAndOtherPostretirementPlansCostsMemberato:TotalUnrecognizedinNetPeriodicPensionCostMember2023-09-300000731802us-gaap:PensionPlansDefinedBenefitMember2023-10-012024-09-300000731802us-gaap:PensionPlansDefinedBenefitMember2022-10-012023-09-300000731802us-gaap:PensionPlansDefinedBenefitMembersrt:MinimumMember2023-10-012024-09-300000731802us-gaap:PensionPlansDefinedBenefitMembersrt:MaximumMember2023-10-012024-09-300000731802us-gaap:PensionPlansDefinedBenefitMembersrt:MinimumMemberato:DomesticEquitySecuritiesMember2024-09-300000731802us-gaap:PensionPlansDefinedBenefitMembersrt:MaximumMemberato:DomesticEquitySecuritiesMember2024-09-300000731802us-gaap:PensionPlansDefinedBenefitMemberato:DomesticEquitySecuritiesMember2024-09-300000731802us-gaap:PensionPlansDefinedBenefitMemberato:DomesticEquitySecuritiesMember2023-09-300000731802us-gaap:PensionPlansDefinedBenefitMembersrt:MinimumMemberato:InternationalEquitySecuritiesMember2024-09-300000731802us-gaap:PensionPlansDefinedBenefitMembersrt:MaximumMemberato:InternationalEquitySecuritiesMember2024-09-300000731802us-gaap:PensionPlansDefinedBenefitMemberato:InternationalEquitySecuritiesMember2024-09-300000731802us-gaap:PensionPlansDefinedBenefitMemberato:InternationalEquitySecuritiesMember2023-09-300000731802us-gaap:PensionPlansDefinedBenefitMembersrt:MinimumMemberus-gaap:FixedIncomeSecuritiesMember2024-09-300000731802us-gaap:PensionPlansDefinedBenefitMembersrt:MaximumMemberus-gaap:FixedIncomeSecuritiesMember2024-09-300000731802us-gaap:PensionPlansDefinedBenefitMemberus-gaap:FixedIncomeSecuritiesMember2024-09-300000731802us-gaap:PensionPlansDefinedBenefitMemberus-gaap:FixedIncomeSecuritiesMember2023-09-300000731802us-gaap:PensionPlansDefinedBenefitMembersrt:MinimumMemberato:CompanyStockMember2024-09-300000731802us-gaap:PensionPlansDefinedBenefitMembersrt:MaximumMemberato:CompanyStockMember2024-09-300000731802us-gaap:PensionPlansDefinedBenefitMemberato:CompanyStockMember2024-09-300000731802us-gaap:PensionPlansDefinedBenefitMemberato:CompanyStockMember2023-09-300000731802us-gaap:PensionPlansDefinedBenefitMembersrt:MinimumMemberato:OtherInvestmentAssetsMember2024-09-300000731802us-gaap:PensionPlansDefinedBenefitMembersrt:MaximumMemberato:OtherInvestmentAssetsMember2024-09-300000731802us-gaap:PensionPlansDefinedBenefitMemberato:OtherInvestmentAssetsMember2024-09-300000731802us-gaap:PensionPlansDefinedBenefitMemberato:OtherInvestmentAssetsMember2023-09-300000731802us-gaap:PensionPlansDefinedBenefitMember2024-09-300000731802us-gaap:PensionPlansDefinedBenefitMember2023-09-300000731802us-gaap:PensionPlansDefinedBenefitMember2021-10-012022-09-300000731802us-gaap:PensionPlansDefinedBenefitMember2022-09-300000731802us-gaap:FairValueInputsLevel1Memberus-gaap:PensionPlansDefinedBenefitMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:EquitySecuritiesMember2024-09-300000731802us-gaap:FairValueInputsLevel2Memberus-gaap:PensionPlansDefinedBenefitMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:EquitySecuritiesMember2024-09-300000731802us-gaap:FairValueInputsLevel3Memberus-gaap:PensionPlansDefinedBenefitMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:EquitySecuritiesMember2024-09-300000731802us-gaap:FairValueInputsLevel12And3Memberus-gaap:PensionPlansDefinedBenefitMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:EquitySecuritiesMember2024-09-300000731802us-gaap:FairValueInputsLevel1Memberus-gaap:PensionPlansDefinedBenefitMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:MoneyMarketFundsMember2024-09-300000731802us-gaap:FairValueInputsLevel2Memberus-gaap:PensionPlansDefinedBenefitMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:MoneyMarketFundsMember2024-09-300000731802us-gaap:FairValueInputsLevel3Memberus-gaap:PensionPlansDefinedBenefitMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:MoneyMarketFundsMember2024-09-300000731802us-gaap:FairValueInputsLevel12And3Memberus-gaap:PensionPlansDefinedBenefitMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:MoneyMarketFundsMember2024-09-300000731802us-gaap:FairValueInputsLevel1Memberus-gaap:PensionPlansDefinedBenefitMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:MutualFundMember2024-09-300000731802us-gaap:FairValueInputsLevel2Memberus-gaap:PensionPlansDefinedBenefitMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:MutualFundMember2024-09-300000731802us-gaap:FairValueInputsLevel3Memberus-gaap:PensionPlansDefinedBenefitMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:MutualFundMember2024-09-300000731802us-gaap:FairValueInputsLevel12And3Memberus-gaap:PensionPlansDefinedBenefitMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:MutualFundMember2024-09-300000731802us-gaap:FairValueInputsLevel1Memberus-gaap:PensionPlansDefinedBenefitMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:USGovernmentSponsoredEnterprisesDebtSecuritiesMember2024-09-300000731802us-gaap:FairValueInputsLevel2Memberus-gaap:PensionPlansDefinedBenefitMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:USGovernmentSponsoredEnterprisesDebtSecuritiesMember2024-09-300000731802us-gaap:FairValueInputsLevel3Memberus-gaap:PensionPlansDefinedBenefitMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:USGovernmentSponsoredEnterprisesDebtSecuritiesMember2024-09-300000731802us-gaap:FairValueInputsLevel12And3Memberus-gaap:PensionPlansDefinedBenefitMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:USGovernmentSponsoredEnterprisesDebtSecuritiesMember2024-09-300000731802us-gaap:FairValueInputsLevel1Memberus-gaap:PensionPlansDefinedBenefitMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:USTreasurySecuritiesMember2024-09-300000731802us-gaap:FairValueInputsLevel2Memberus-gaap:PensionPlansDefinedBenefitMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:USTreasurySecuritiesMember2024-09-300000731802us-gaap:FairValueInputsLevel3Memberus-gaap:PensionPlansDefinedBenefitMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:USTreasurySecuritiesMember2024-09-300000731802us-gaap:FairValueInputsLevel12And3Memberus-gaap:PensionPlansDefinedBenefitMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:USTreasurySecuritiesMember2024-09-300000731802us-gaap:FairValueInputsLevel1Memberus-gaap:PensionPlansDefinedBenefitMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:CorporateDebtSecuritiesMember2024-09-300000731802us-gaap:FairValueInputsLevel2Memberus-gaap:PensionPlansDefinedBenefitMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:CorporateDebtSecuritiesMember2024-09-300000731802us-gaap:FairValueInputsLevel3Memberus-gaap:PensionPlansDefinedBenefitMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:CorporateDebtSecuritiesMember2024-09-300000731802us-gaap:FairValueInputsLevel12And3Memberus-gaap:PensionPlansDefinedBenefitMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:CorporateDebtSecuritiesMember2024-09-300000731802us-gaap:FairValueInputsLevel1Memberus-gaap:PensionPlansDefinedBenefitMemberus-gaap:FairValueMeasurementsRecurringMember2024-09-300000731802us-gaap:FairValueInputsLevel2Memberus-gaap:PensionPlansDefinedBenefitMemberus-gaap:FairValueMeasurementsRecurringMember2024-09-300000731802us-gaap:FairValueInputsLevel3Memberus-gaap:PensionPlansDefinedBenefitMemberus-gaap:FairValueMeasurementsRecurringMember2024-09-300000731802us-gaap:FairValueInputsLevel12And3Memberus-gaap:PensionPlansDefinedBenefitMemberus-gaap:FairValueMeasurementsRecurringMember2024-09-300000731802us-gaap:FairValueMeasuredAtNetAssetValuePerShareMemberus-gaap:PensionPlansDefinedBenefitMemberus-gaap:FairValueMeasurementsRecurringMemberato:CommonCollectiveTrustsMember2024-09-300000731802us-gaap:FairValueMeasuredAtNetAssetValuePerShareMemberus-gaap:PensionPlansDefinedBenefitMemberus-gaap:FairValueMeasurementsRecurringMemberato:LimitedPartnershipInterestMember2024-09-300000731802us-gaap:PensionPlansDefinedBenefitMemberus-gaap:FairValueMeasurementsRecurringMember2024-09-300000731802us-gaap:FairValueInputsLevel1Memberus-gaap:PensionPlansDefinedBenefitMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:EquitySecuritiesMember2023-09-300000731802us-gaap:FairValueInputsLevel2Memberus-gaap:PensionPlansDefinedBenefitMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:EquitySecuritiesMember2023-09-300000731802us-gaap:FairValueInputsLevel3Memberus-gaap:PensionPlansDefinedBenefitMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:EquitySecuritiesMember2023-09-300000731802us-gaap:FairValueInputsLevel12And3Memberus-gaap:PensionPlansDefinedBenefitMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:EquitySecuritiesMember2023-09-300000731802us-gaap:FairValueInputsLevel1Memberus-gaap:PensionPlansDefinedBenefitMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:MoneyMarketFundsMember2023-09-300000731802us-gaap:FairValueInputsLevel2Memberus-gaap:PensionPlansDefinedBenefitMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:MoneyMarketFundsMember2023-09-300000731802us-gaap:FairValueInputsLevel3Memberus-gaap:PensionPlansDefinedBenefitMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:MoneyMarketFundsMember2023-09-300000731802us-gaap:FairValueInputsLevel12And3Memberus-gaap:PensionPlansDefinedBenefitMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:MoneyMarketFundsMember2023-09-300000731802us-gaap:FairValueInputsLevel1Memberus-gaap:PensionPlansDefinedBenefitMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:MutualFundMember2023-09-300000731802us-gaap:FairValueInputsLevel2Memberus-gaap:PensionPlansDefinedBenefitMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:MutualFundMember2023-09-300000731802us-gaap:FairValueInputsLevel3Memberus-gaap:PensionPlansDefinedBenefitMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:MutualFundMember2023-09-300000731802us-gaap:FairValueInputsLevel12And3Memberus-gaap:PensionPlansDefinedBenefitMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:MutualFundMember2023-09-300000731802us-gaap:FairValueInputsLevel1Memberus-gaap:PensionPlansDefinedBenefitMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:USGovernmentSponsoredEnterprisesDebtSecuritiesMember2023-09-300000731802us-gaap:FairValueInputsLevel2Memberus-gaap:PensionPlansDefinedBenefitMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:USGovernmentSponsoredEnterprisesDebtSecuritiesMember2023-09-300000731802us-gaap:FairValueInputsLevel3Memberus-gaap:PensionPlansDefinedBenefitMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:USGovernmentSponsoredEnterprisesDebtSecuritiesMember2023-09-300000731802us-gaap:FairValueInputsLevel12And3Memberus-gaap:PensionPlansDefinedBenefitMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:USGovernmentSponsoredEnterprisesDebtSecuritiesMember2023-09-300000731802us-gaap:FairValueInputsLevel1Memberus-gaap:PensionPlansDefinedBenefitMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:USTreasurySecuritiesMember2023-09-300000731802us-gaap:FairValueInputsLevel2Memberus-gaap:PensionPlansDefinedBenefitMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:USTreasurySecuritiesMember2023-09-300000731802us-gaap:FairValueInputsLevel3Memberus-gaap:PensionPlansDefinedBenefitMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:USTreasurySecuritiesMember2023-09-300000731802us-gaap:FairValueInputsLevel12And3Memberus-gaap:PensionPlansDefinedBenefitMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:USTreasurySecuritiesMember2023-09-300000731802us-gaap:FairValueInputsLevel1Memberus-gaap:PensionPlansDefinedBenefitMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:CorporateDebtSecuritiesMember2023-09-300000731802us-gaap:FairValueInputsLevel2Memberus-gaap:PensionPlansDefinedBenefitMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:CorporateDebtSecuritiesMember2023-09-300000731802us-gaap:FairValueInputsLevel3Memberus-gaap:PensionPlansDefinedBenefitMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:CorporateDebtSecuritiesMember2023-09-300000731802us-gaap:FairValueInputsLevel12And3Memberus-gaap:PensionPlansDefinedBenefitMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:CorporateDebtSecuritiesMember2023-09-300000731802us-gaap:FairValueInputsLevel1Memberus-gaap:PensionPlansDefinedBenefitMemberus-gaap:FairValueMeasurementsRecurringMember2023-09-300000731802us-gaap:FairValueInputsLevel2Memberus-gaap:PensionPlansDefinedBenefitMemberus-gaap:FairValueMeasurementsRecurringMember2023-09-300000731802us-gaap:FairValueInputsLevel3Memberus-gaap:PensionPlansDefinedBenefitMemberus-gaap:FairValueMeasurementsRecurringMember2023-09-300000731802us-gaap:FairValueInputsLevel12And3Memberus-gaap:PensionPlansDefinedBenefitMemberus-gaap:FairValueMeasurementsRecurringMember2023-09-300000731802us-gaap:FairValueMeasuredAtNetAssetValuePerShareMemberus-gaap:PensionPlansDefinedBenefitMemberus-gaap:FairValueMeasurementsRecurringMemberato:CommonCollectiveTrustsMember2023-09-300000731802us-gaap:FairValueMeasuredAtNetAssetValuePerShareMemberus-gaap:PensionPlansDefinedBenefitMemberus-gaap:FairValueMeasurementsRecurringMemberato:LimitedPartnershipInterestMember2023-09-300000731802us-gaap:PensionPlansDefinedBenefitMemberus-gaap:FairValueMeasurementsRecurringMember2023-09-300000731802ato:SupplementalExecutiveBenefitPlanMember2024-09-300000731802ato:SupplementalExecutiveBenefitPlanMemberus-gaap:SupplementalEmployeeRetirementPlanDefinedBenefitMember2023-10-012024-09-300000731802ato:A1998SupplementalExecutiveRetirementPlanMemberus-gaap:SupplementalEmployeeRetirementPlanDefinedBenefitMember2023-10-012024-09-300000731802ato:A2009SupplementalExecutiveRetirementPlanDefinedBenefitMemberus-gaap:SupplementalEmployeeRetirementPlanDefinedBenefitMember2023-10-012024-09-300000731802us-gaap:SupplementalEmployeeRetirementPlanDefinedBenefitMembersrt:ExecutiveOfficerMember2023-10-012024-09-300000731802us-gaap:SupplementalEmployeeRetirementPlanDefinedBenefitMembersrt:ExecutiveOfficerMember2022-10-012023-09-300000731802us-gaap:SupplementalEmployeeRetirementPlanDefinedBenefitMember2024-09-300000731802us-gaap:SupplementalEmployeeRetirementPlanDefinedBenefitMember2023-09-300000731802us-gaap:SupplementalEmployeeRetirementPlanDefinedBenefitMember2023-10-012024-09-300000731802us-gaap:SupplementalEmployeeRetirementPlanDefinedBenefitMember2022-10-012023-09-300000731802us-gaap:SupplementalEmployeeRetirementPlanDefinedBenefitMember2021-10-012022-09-300000731802us-gaap:SupplementalEmployeeRetirementPlanDefinedBenefitMember2022-09-300000731802us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMembersrt:MinimumMember2024-09-300000731802us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMembersrt:MaximumMember2024-09-300000731802us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMemberato:DiversifiedInvestmentFundsMember2023-10-012024-09-300000731802us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMemberato:DiversifiedInvestmentFundsMember2024-09-300000731802us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMemberato:DiversifiedInvestmentFundsMember2023-09-300000731802us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMemberus-gaap:CashAndCashEquivalentsMember2024-09-300000731802us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMemberus-gaap:CashAndCashEquivalentsMember2023-09-300000731802us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember2024-09-300000731802us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember2023-09-300000731802us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember2023-10-012024-09-300000731802us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember2022-10-012023-09-300000731802us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember2021-10-012022-09-300000731802us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember2022-09-300000731802us-gaap:FairValueInputsLevel1Memberus-gaap:OtherPostretirementBenefitPlansDefinedBenefitMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:MoneyMarketFundsMember2024-09-300000731802us-gaap:FairValueInputsLevel2Memberus-gaap:OtherPostretirementBenefitPlansDefinedBenefitMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:MoneyMarketFundsMember2024-09-300000731802us-gaap:FairValueInputsLevel3Memberus-gaap:OtherPostretirementBenefitPlansDefinedBenefitMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:MoneyMarketFundsMember2024-09-300000731802us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:MoneyMarketFundsMember2024-09-300000731802us-gaap:FairValueInputsLevel1Memberus-gaap:OtherPostretirementBenefitPlansDefinedBenefitMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:MutualFundMember2024-09-300000731802us-gaap:FairValueInputsLevel2Memberus-gaap:OtherPostretirementBenefitPlansDefinedBenefitMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:MutualFundMember2024-09-300000731802us-gaap:FairValueInputsLevel3Memberus-gaap:OtherPostretirementBenefitPlansDefinedBenefitMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:MutualFundMember2024-09-300000731802us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:MutualFundMember2024-09-300000731802us-gaap:FairValueInputsLevel1Memberus-gaap:OtherPostretirementBenefitPlansDefinedBenefitMemberus-gaap:FairValueMeasurementsRecurringMember2024-09-300000731802us-gaap:FairValueInputsLevel2Memberus-gaap:OtherPostretirementBenefitPlansDefinedBenefitMemberus-gaap:FairValueMeasurementsRecurringMember2024-09-300000731802us-gaap:FairValueInputsLevel3Memberus-gaap:OtherPostretirementBenefitPlansDefinedBenefitMemberus-gaap:FairValueMeasurementsRecurringMember2024-09-300000731802us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMemberus-gaap:FairValueMeasurementsRecurringMember2024-09-300000731802us-gaap:FairValueInputsLevel1Memberus-gaap:OtherPostretirementBenefitPlansDefinedBenefitMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:MoneyMarketFundsMember2023-09-300000731802us-gaap:FairValueInputsLevel2Memberus-gaap:OtherPostretirementBenefitPlansDefinedBenefitMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:MoneyMarketFundsMember2023-09-300000731802us-gaap:FairValueInputsLevel3Memberus-gaap:OtherPostretirementBenefitPlansDefinedBenefitMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:MoneyMarketFundsMember2023-09-300000731802us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:MoneyMarketFundsMember2023-09-300000731802us-gaap:FairValueInputsLevel1Memberus-gaap:OtherPostretirementBenefitPlansDefinedBenefitMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:MutualFundMember2023-09-300000731802us-gaap:FairValueInputsLevel2Memberus-gaap:OtherPostretirementBenefitPlansDefinedBenefitMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:MutualFundMember2023-09-300000731802us-gaap:FairValueInputsLevel3Memberus-gaap:OtherPostretirementBenefitPlansDefinedBenefitMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:MutualFundMember2023-09-300000731802us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMemberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:MutualFundMember2023-09-300000731802us-gaap:FairValueInputsLevel1Memberus-gaap:OtherPostretirementBenefitPlansDefinedBenefitMemberus-gaap:FairValueMeasurementsRecurringMember2023-09-300000731802us-gaap:FairValueInputsLevel2Memberus-gaap:OtherPostretirementBenefitPlansDefinedBenefitMemberus-gaap:FairValueMeasurementsRecurringMember2023-09-300000731802us-gaap:FairValueInputsLevel3Memberus-gaap:OtherPostretirementBenefitPlansDefinedBenefitMemberus-gaap:FairValueMeasurementsRecurringMember2023-09-300000731802us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMemberus-gaap:FairValueMeasurementsRecurringMember2023-09-300000731802ato:RetirementSavingsPlanMember2023-10-012024-09-300000731802ato:RetirementSavingsPlanMemberus-gaap:PensionPlansDefinedBenefitMember2023-10-012024-09-300000731802ato:RetirementSavingsPlanMember2022-10-012023-09-300000731802ato:RetirementSavingsPlanMember2021-10-012022-09-300000731802ato:RetirementSavingsPlanMember2024-09-300000731802ato:RetirementSavingsPlanMember2023-09-300000731802us-gaap:BilledRevenuesMemberus-gaap:TradeAccountsReceivableMember2024-09-300000731802us-gaap:BilledRevenuesMemberus-gaap:TradeAccountsReceivableMember2023-09-300000731802us-gaap:UnbilledRevenuesMemberus-gaap:TradeAccountsReceivableMember2024-09-300000731802us-gaap:UnbilledRevenuesMemberus-gaap:TradeAccountsReceivableMember2023-09-300000731802ato:InsuranceReceivableMember2024-09-300000731802ato:InsuranceReceivableMember2023-09-300000731802ato:OtherAccountsReceivableMember2024-09-300000731802ato:OtherAccountsReceivableMember2023-09-300000731802ato:JacksonMississippiMemberato:NationalTransportationSafetyBoardMember2024-01-242024-01-270000731802ato:NationalTransportationSafetyBoardMember2024-01-270000731802us-gaap:SupplyCommitmentMember2023-10-012024-09-300000731802us-gaap:ShortTermContractWithCustomerMemberus-gaap:SupplyCommitmentMember2023-10-012024-09-300000731802ato:LongtermContractwithCustomerWithinTwoToThreeYearsMemberus-gaap:SupplyCommitmentMember2023-10-012024-09-300000731802us-gaap:SupplyCommitmentMemberato:LongtermContractwithCustomerWithinTwoToThreeYearsMembersrt:MinimumMember2023-10-012024-09-300000731802us-gaap:SupplyCommitmentMemberato:LongtermContractwithCustomerWithinTwoToThreeYearsMembersrt:MaximumMember2023-10-012024-09-300000731802srt:WeightedAverageMemberus-gaap:SupplyCommitmentMember2023-10-012024-09-300000731802us-gaap:DomesticCountryMember2024-09-300000731802us-gaap:StateAndLocalJurisdictionMember2024-09-300000731802us-gaap:OtherCurrentLiabilitiesMemberus-gaap:DeferredIncomeTaxChargesMember2024-09-300000731802us-gaap:OtherCurrentLiabilitiesMemberus-gaap:DeferredIncomeTaxChargesMember2023-09-300000731802ato:RegulatoryExcessDeferredTaxesToBeReturnedTrancheOneMember2024-09-300000731802ato:RegulatoryExcessDeferredTaxesToBeReturnedTrancheOneMembersrt:MinimumMember2023-10-012024-09-300000731802ato:RegulatoryExcessDeferredTaxesToBeReturnedTrancheOneMembersrt:MaximumMember2023-10-012024-09-300000731802ato:RegulatoryExcessDeferredTaxesToBeReturnedTrancheTwoMember2024-09-300000731802ato:RegulatoryExcessDeferredTaxesToBeReturnedTrancheTwoMembersrt:MinimumMember2023-10-012024-09-300000731802ato:RegulatoryExcessDeferredTaxesToBeReturnedTrancheTwoMembersrt:MaximumMember2023-10-012024-09-300000731802ato:RegulatoryExcessDeferredTaxesToBeReturnedTrancheThreeMember2024-09-300000731802ato:GasPurchasesMemberus-gaap:CommodityContractMemberus-gaap:NondesignatedMembersrt:MinimumMember2024-09-300000731802ato:GasPurchasesMemberus-gaap:CommodityContractMemberus-gaap:NondesignatedMembersrt:MaximumMember2024-09-300000731802ato:GasPurchasesMemberus-gaap:CommodityContractMemberus-gaap:NondesignatedMember2023-10-012024-09-300000731802ato:GasPurchasesMemberus-gaap:CommodityContractMemberus-gaap:NondesignatedMembersrt:WeightedAverageMember2023-10-012024-09-300000731802ato:ForwardInterestRateSwapPlannedIssuedFiscal2026Memberus-gaap:CashFlowHedgingMemberus-gaap:DesignatedAsHedgingInstrumentMember2024-09-300000731802ato:ForwardInterestRateSwapMemberus-gaap:CashFlowHedgingMemberus-gaap:DesignatedAsHedgingInstrumentMember2024-09-300000731802us-gaap:InterestRateContractMemberus-gaap:DesignatedAsHedgingInstrumentMemberus-gaap:OtherNoncurrentAssetsMember2024-09-300000731802us-gaap:InterestRateContractMemberus-gaap:DesignatedAsHedgingInstrumentMemberus-gaap:OtherNoncurrentLiabilitiesMember2024-09-300000731802us-gaap:DesignatedAsHedgingInstrumentMember2024-09-300000731802us-gaap:CommodityContractMemberus-gaap:NondesignatedMemberus-gaap:OtherCurrentAssetsMember2024-09-300000731802us-gaap:CommodityContractMemberus-gaap:NondesignatedMemberus-gaap:OtherCurrentLiabilitiesMember2024-09-300000731802us-gaap:CommodityContractMemberus-gaap:NondesignatedMemberus-gaap:OtherNoncurrentAssetsMember2024-09-300000731802us-gaap:CommodityContractMemberus-gaap:NondesignatedMemberus-gaap:OtherNoncurrentLiabilitiesMember2024-09-300000731802us-gaap:NondesignatedMember2024-09-300000731802us-gaap:InterestRateContractMemberus-gaap:DesignatedAsHedgingInstrumentMemberus-gaap:OtherNoncurrentAssetsMember2023-09-300000731802us-gaap:InterestRateContractMemberus-gaap:DesignatedAsHedgingInstrumentMemberus-gaap:OtherNoncurrentLiabilitiesMember2023-09-300000731802us-gaap:DesignatedAsHedgingInstrumentMember2023-09-300000731802us-gaap:CommodityContractMemberus-gaap:NondesignatedMemberus-gaap:OtherCurrentAssetsMember2023-09-300000731802us-gaap:CommodityContractMemberus-gaap:NondesignatedMemberus-gaap:OtherCurrentLiabilitiesMember2023-09-300000731802us-gaap:CommodityContractMemberus-gaap:NondesignatedMemberus-gaap:OtherNoncurrentAssetsMember2023-09-300000731802us-gaap:CommodityContractMemberus-gaap:NondesignatedMemberus-gaap:OtherNoncurrentLiabilitiesMember2023-09-300000731802us-gaap:NondesignatedMember2023-09-300000731802us-gaap:InterestRateContractMember2023-10-012024-09-300000731802us-gaap:FairValueInputsLevel1Member2024-09-300000731802us-gaap:FairValueInputsLevel2Member2024-09-300000731802us-gaap:FairValueInputsLevel3Member2024-09-300000731802us-gaap:FairValueInputsLevel1Memberus-gaap:EquitySecuritiesMember2024-09-300000731802us-gaap:FairValueInputsLevel2Memberus-gaap:EquitySecuritiesMember2024-09-300000731802us-gaap:FairValueInputsLevel3Memberus-gaap:EquitySecuritiesMember2024-09-300000731802us-gaap:EquitySecuritiesMember2024-09-300000731802us-gaap:FairValueInputsLevel1Memberus-gaap:FixedIncomeFundsMember2024-09-300000731802us-gaap:FairValueInputsLevel2Memberus-gaap:FixedIncomeFundsMember2024-09-300000731802us-gaap:FairValueInputsLevel3Memberus-gaap:FixedIncomeFundsMember2024-09-300000731802us-gaap:FixedIncomeFundsMember2024-09-300000731802us-gaap:FairValueInputsLevel1Memberus-gaap:DebtSecuritiesMember2024-09-300000731802us-gaap:FairValueInputsLevel2Memberus-gaap:DebtSecuritiesMember2024-09-300000731802us-gaap:FairValueInputsLevel3Memberus-gaap:DebtSecuritiesMember2024-09-300000731802us-gaap:DebtSecuritiesMember2024-09-300000731802us-gaap:FairValueInputsLevel1Memberus-gaap:MoneyMarketFundsMember2024-09-300000731802us-gaap:FairValueInputsLevel2Memberus-gaap:MoneyMarketFundsMember2024-09-300000731802us-gaap:FairValueInputsLevel3Memberus-gaap:MoneyMarketFundsMember2024-09-300000731802us-gaap:MoneyMarketFundsMember2024-09-300000731802us-gaap:FairValueInputsLevel1Member2023-09-300000731802us-gaap:FairValueInputsLevel2Member2023-09-300000731802us-gaap:FairValueInputsLevel3Member2023-09-300000731802us-gaap:FairValueInputsLevel1Memberus-gaap:EquitySecuritiesMember2023-09-300000731802us-gaap:FairValueInputsLevel2Memberus-gaap:EquitySecuritiesMember2023-09-300000731802us-gaap:FairValueInputsLevel3Memberus-gaap:EquitySecuritiesMember2023-09-300000731802us-gaap:EquitySecuritiesMember2023-09-300000731802us-gaap:FairValueInputsLevel1Memberus-gaap:FixedIncomeFundsMember2023-09-300000731802us-gaap:FairValueInputsLevel2Memberus-gaap:FixedIncomeFundsMember2023-09-300000731802us-gaap:FairValueInputsLevel3Memberus-gaap:FixedIncomeFundsMember2023-09-300000731802us-gaap:FixedIncomeFundsMember2023-09-300000731802us-gaap:FairValueInputsLevel1Memberus-gaap:DebtSecuritiesMember2023-09-300000731802us-gaap:FairValueInputsLevel2Memberus-gaap:DebtSecuritiesMember2023-09-300000731802us-gaap:FairValueInputsLevel3Memberus-gaap:DebtSecuritiesMember2023-09-300000731802us-gaap:DebtSecuritiesMember2023-09-300000731802us-gaap:FairValueInputsLevel1Memberus-gaap:MoneyMarketFundsMember2023-09-300000731802us-gaap:FairValueInputsLevel2Memberus-gaap:MoneyMarketFundsMember2023-09-300000731802us-gaap:FairValueInputsLevel3Memberus-gaap:MoneyMarketFundsMember2023-09-300000731802us-gaap:MoneyMarketFundsMember2023-09-3000007318022024-07-012024-09-30

00007318022025FYFALSEhttp://fasb.org/us-gaap/2025#PublicUtilitiesPropertyPlantAndEquipmentNethttp://fasb.org/us-gaap/2025#PublicUtilitiesPropertyPlantAndEquipmentNethttp://fasb.org/us-gaap/2025#OtherAssetsNoncurrenthttp://fasb.org/us-gaap/2025#OtherAssetsNoncurrenthttp://fasb.org/us-gaap/2025#LongTermDebtAndCapitalLeaseObligationsCurrenthttp://fasb.org/us-gaap/2025#LongTermDebtAndCapitalLeaseObligationsCurrenthttp://fasb.org/us-gaap/2025#OtherLiabilitiesCurrenthttp://fasb.org/us-gaap/2025#OtherLiabilitiesCurrenthttp://fasb.org/us-gaap/2025#LongTermDebtAndCapitalLeaseObligationshttp://fasb.org/us-gaap/2025#LongTermDebtAndCapitalLeaseObligationshttp://fasb.org/us-gaap/2025#OtherLiabilitiesNoncurrenthttp://fasb.org/us-gaap/2025#OtherLiabilitiesNoncurrentP3Yhttp://fasb.org/us-gaap/2025#OtherNonoperatingIncomeExpensehttp://fasb.org/us-gaap/2025#OtherNonoperatingIncomeExpensehttp://fasb.org/us-gaap/2025#OtherNonoperatingIncomeExpensehttp://fasb.org/us-gaap/2025#OtherNonoperatingIncomeExpensehttp://fasb.org/us-gaap/2025#OtherNonoperatingIncomeExpensehttp://fasb.org/us-gaap/2025#OtherNonoperatingIncomeExpensehttp://fasb.org/us-gaap/2025#OtherNonoperatingIncomeExpensehttp://fasb.org/us-gaap/2025#OtherNonoperatingIncomeExpensehttp://fasb.org/us-gaap/2025#OtherNonoperatingIncomeExpenseP2Yiso4217:USDxbrli:sharesiso4217:USDxbrli:sharesato:customerato:regulated_distribution_divisionato:facilityutr:miato:planxbrli:pureato:segmentato:stateato:service_centerato:credit_facilityato:incidentato:fatalityutr:MMcfiso4217:USDutr:Mcf00007318022024-10-012025-09-3000007318022025-03-3100007318022025-11-1000007318022025-09-3000007318022024-09-300000731802us-gaap:OperatingSegmentsMemberato:DistributionSegmentMember2024-10-012025-09-300000731802us-gaap:OperatingSegmentsMemberato:DistributionSegmentMember2023-10-012024-09-300000731802us-gaap:OperatingSegmentsMemberato:DistributionSegmentMember2022-10-012023-09-300000731802us-gaap:OperatingSegmentsMemberato:PipelineandStorageSegmentMember2024-10-012025-09-300000731802us-gaap:OperatingSegmentsMemberato:PipelineandStorageSegmentMember2023-10-012024-09-300000731802us-gaap:OperatingSegmentsMemberato:PipelineandStorageSegmentMember2022-10-012023-09-300000731802us-gaap:IntersegmentEliminationMember2024-10-012025-09-300000731802us-gaap:IntersegmentEliminationMember2023-10-012024-09-300000731802us-gaap:IntersegmentEliminationMember2022-10-012023-09-3000007318022023-10-012024-09-3000007318022022-10-012023-09-300000731802us-gaap:CommonStockMember2022-09-300000731802us-gaap:AdditionalPaidInCapitalMember2022-09-300000731802us-gaap:AccumulatedOtherComprehensiveIncomeMember2022-09-300000731802us-gaap:RetainedEarningsMember2022-09-3000007318022022-09-300000731802us-gaap:RetainedEarningsMember2022-10-012023-09-300000731802us-gaap:AccumulatedOtherComprehensiveIncomeMember2022-10-012023-09-300000731802us-gaap:CommonStockMember2022-10-012023-09-300000731802us-gaap:AdditionalPaidInCapitalMember2022-10-012023-09-300000731802us-gaap:CommonStockMember2023-09-300000731802us-gaap:AdditionalPaidInCapitalMember2023-09-300000731802us-gaap:AccumulatedOtherComprehensiveIncomeMember2023-09-300000731802us-gaap:RetainedEarningsMember2023-09-3000007318022023-09-300000731802us-gaap:RetainedEarningsMember2023-10-012024-09-300000731802us-gaap:AccumulatedOtherComprehensiveIncomeMember2023-10-012024-09-300000731802us-gaap:CommonStockMember2023-10-012024-09-300000731802us-gaap:AdditionalPaidInCapitalMember2023-10-012024-09-300000731802us-gaap:CommonStockMember2024-09-300000731802us-gaap:AdditionalPaidInCapitalMember2024-09-300000731802us-gaap:AccumulatedOtherComprehensiveIncomeMember2024-09-300000731802us-gaap:RetainedEarningsMember2024-09-300000731802us-gaap:RetainedEarningsMember2024-10-012025-09-300000731802us-gaap:AccumulatedOtherComprehensiveIncomeMember2024-10-012025-09-300000731802us-gaap:CommonStockMember2024-10-012025-09-300000731802us-gaap:AdditionalPaidInCapitalMember2024-10-012025-09-300000731802us-gaap:CommonStockMember2025-09-300000731802us-gaap:AdditionalPaidInCapitalMember2025-09-300000731802us-gaap:AccumulatedOtherComprehensiveIncomeMember2025-09-300000731802us-gaap:RetainedEarningsMember2025-09-300000731802stpr:LAato:PipelineandStorageSegmentMember2025-09-300000731802ato:PipelineandStorageSegmentMember2024-10-012025-09-300000731802ato:PipelineandStorageSegmentMember2023-11-302023-11-300000731802ato:PipelineandStorageSegmentMember2023-12-012023-12-310000731802us-gaap:PensionAndOtherPostretirementPlansCostsMember2025-09-300000731802us-gaap:PensionAndOtherPostretirementPlansCostsMember2024-09-300000731802ato:InfrastructureMechanismsMember2025-09-300000731802ato:InfrastructureMechanismsMember2024-09-300000731802us-gaap:StormCostsMember2025-09-300000731802us-gaap:StormCostsMember2024-09-300000731802us-gaap:DeferredFuelCostsMember2025-09-300000731802us-gaap:DeferredFuelCostsMember2024-09-300000731802us-gaap:DeferredIncomeTaxChargesMember2025-09-300000731802us-gaap:DeferredIncomeTaxChargesMember2024-09-300000731802us-gaap:LossOnReacquiredDebtMember2025-09-300000731802us-gaap:LossOnReacquiredDebtMember2024-09-300000731802us-gaap:DeferredProjectCostsMember2025-09-300000731802us-gaap:DeferredProjectCostsMember2024-09-300000731802ato:SystemSafetyAndIntegrityRidersMember2025-09-300000731802ato:SystemSafetyAndIntegrityRidersMember2024-09-300000731802us-gaap:OtherRegulatoryAssetsLiabilitiesMember2025-09-300000731802us-gaap:OtherRegulatoryAssetsLiabilitiesMember2024-09-300000731802us-gaap:DeferredIncomeTaxChargesMember2025-09-300000731802us-gaap:DeferredIncomeTaxChargesMember2024-09-300000731802us-gaap:RemovalCostsMember2025-09-300000731802us-gaap:RemovalCostsMember2024-09-300000731802us-gaap:DeferredFuelCostsMember2025-09-300000731802us-gaap:DeferredFuelCostsMember2024-09-300000731802ato:RegulatoryClauseRevenuesOverRecoveredMember2025-09-300000731802ato:RegulatoryClauseRevenuesOverRecoveredMember2024-09-300000731802us-gaap:PensionAndOtherPostretirementPlansCostsMember2025-09-300000731802us-gaap:PensionAndOtherPostretirementPlansCostsMember2024-09-300000731802us-gaap:OtherRegulatoryAssetsLiabilitiesMember2025-09-300000731802us-gaap:OtherRegulatoryAssetsLiabilitiesMember2024-09-300000731802ato:DistributionSegmentMember2024-10-012025-09-300000731802us-gaap:IntersegmentEliminationMemberato:DistributionSegmentMember2024-10-012025-09-300000731802us-gaap:IntersegmentEliminationMemberato:PipelineandStorageSegmentMember2024-10-012025-09-300000731802us-gaap:OperatingSegmentsMember2024-10-012025-09-300000731802ato:DistributionSegmentMember2023-10-012024-09-300000731802ato:PipelineandStorageSegmentMember2023-10-012024-09-300000731802us-gaap:IntersegmentEliminationMemberato:DistributionSegmentMember2023-10-012024-09-300000731802us-gaap:IntersegmentEliminationMemberato:PipelineandStorageSegmentMember2023-10-012024-09-300000731802us-gaap:OperatingSegmentsMember2023-10-012024-09-300000731802ato:DistributionSegmentMember2022-10-012023-09-300000731802ato:PipelineandStorageSegmentMember2022-10-012023-09-300000731802us-gaap:IntersegmentEliminationMemberato:DistributionSegmentMember2022-10-012023-09-300000731802us-gaap:IntersegmentEliminationMemberato:PipelineandStorageSegmentMember2022-10-012023-09-300000731802us-gaap:OperatingSegmentsMember2022-10-012023-09-300000731802us-gaap:NaturalGasUsRegulatedMemberato:ResidentialCustomersMemberato:DistributionSegmentMember2024-10-012025-09-300000731802us-gaap:NaturalGasUsRegulatedMemberato:ResidentialCustomersMemberato:DistributionSegmentMember2023-10-012024-09-300000731802us-gaap:NaturalGasUsRegulatedMemberato:ResidentialCustomersMemberato:DistributionSegmentMember2022-10-012023-09-300000731802us-gaap:NaturalGasUsRegulatedMemberato:CommercialCustomersMemberato:DistributionSegmentMember2024-10-012025-09-300000731802us-gaap:NaturalGasUsRegulatedMemberato:CommercialCustomersMemberato:DistributionSegmentMember2023-10-012024-09-300000731802us-gaap:NaturalGasUsRegulatedMemberato:CommercialCustomersMemberato:DistributionSegmentMember2022-10-012023-09-300000731802us-gaap:NaturalGasUsRegulatedMemberato:IndustrialCustomersMemberato:DistributionSegmentMember2024-10-012025-09-300000731802us-gaap:NaturalGasUsRegulatedMemberato:IndustrialCustomersMemberato:DistributionSegmentMember2023-10-012024-09-300000731802us-gaap:NaturalGasUsRegulatedMemberato:IndustrialCustomersMemberato:DistributionSegmentMember2022-10-012023-09-300000731802us-gaap:NaturalGasUsRegulatedMemberato:PublicAuthorityandOtherCustomersMemberato:DistributionSegmentMember2024-10-012025-09-300000731802us-gaap:NaturalGasUsRegulatedMemberato:PublicAuthorityandOtherCustomersMemberato:DistributionSegmentMember2023-10-012024-09-300000731802us-gaap:NaturalGasUsRegulatedMemberato:PublicAuthorityandOtherCustomersMemberato:DistributionSegmentMember2022-10-012023-09-300000731802us-gaap:NaturalGasUsRegulatedMemberato:DistributionSegmentMember2024-10-012025-09-300000731802us-gaap:NaturalGasUsRegulatedMemberato:DistributionSegmentMember2023-10-012024-09-300000731802us-gaap:NaturalGasUsRegulatedMemberato:DistributionSegmentMember2022-10-012023-09-300000731802us-gaap:NaturalGasGatheringTransportationMarketingAndProcessingMemberato:DistributionSegmentMember2024-10-012025-09-300000731802us-gaap:NaturalGasGatheringTransportationMarketingAndProcessingMemberato:DistributionSegmentMember2023-10-012024-09-300000731802us-gaap:NaturalGasGatheringTransportationMarketingAndProcessingMemberato:DistributionSegmentMember2022-10-012023-09-300000731802ato:NaturalGasOtherMemberato:DistributionSegmentMember2024-10-012025-09-300000731802ato:NaturalGasOtherMemberato:DistributionSegmentMember2023-10-012024-09-300000731802ato:NaturalGasOtherMemberato:DistributionSegmentMember2022-10-012023-09-300000731802us-gaap:OperatingSegmentsMemberato:DistributionSegmentMember2025-09-300000731802us-gaap:OperatingSegmentsMemberato:PipelineandStorageSegmentMember2025-09-300000731802us-gaap:OperatingSegmentsMember2025-09-300000731802us-gaap:IntersegmentEliminationMember2025-09-300000731802us-gaap:OperatingSegmentsMemberato:DistributionSegmentMember2024-09-300000731802us-gaap:OperatingSegmentsMemberato:PipelineandStorageSegmentMember2024-09-300000731802us-gaap:OperatingSegmentsMember2024-09-300000731802us-gaap:IntersegmentEliminationMember2024-09-300000731802us-gaap:OperatingSegmentsMemberato:GassalesrevenueMemberato:ResidentialCustomersMemberato:DistributionSegmentMember2024-10-012025-09-300000731802us-gaap:OperatingSegmentsMemberato:GassalesrevenueMemberato:ResidentialCustomersMemberato:PipelineandStorageSegmentMember2024-10-012025-09-300000731802us-gaap:OperatingSegmentsMemberato:GassalesrevenueMemberato:CommercialCustomersMemberato:DistributionSegmentMember2024-10-012025-09-300000731802us-gaap:OperatingSegmentsMemberato:GassalesrevenueMemberato:CommercialCustomersMemberato:PipelineandStorageSegmentMember2024-10-012025-09-300000731802us-gaap:OperatingSegmentsMemberato:GassalesrevenueMemberato:IndustrialCustomersMemberato:DistributionSegmentMember2024-10-012025-09-300000731802us-gaap:OperatingSegmentsMemberato:GassalesrevenueMemberato:IndustrialCustomersMemberato:PipelineandStorageSegmentMember2024-10-012025-09-300000731802us-gaap:OperatingSegmentsMemberato:GassalesrevenueMemberato:PublicAuthorityandOtherCustomersMemberato:DistributionSegmentMember2024-10-012025-09-300000731802us-gaap:OperatingSegmentsMemberato:GassalesrevenueMemberato:PublicAuthorityandOtherCustomersMemberato:PipelineandStorageSegmentMember2024-10-012025-09-300000731802us-gaap:OperatingSegmentsMemberato:GassalesrevenueMemberato:DistributionSegmentMember2024-10-012025-09-300000731802us-gaap:OperatingSegmentsMemberato:GassalesrevenueMemberato:PipelineandStorageSegmentMember2024-10-012025-09-300000731802us-gaap:OperatingSegmentsMemberato:TransportationrevenueMemberato:DistributionSegmentMember2024-10-012025-09-300000731802us-gaap:OperatingSegmentsMemberato:TransportationrevenueMemberato:PipelineandStorageSegmentMember2024-10-012025-09-300000731802us-gaap:OperatingSegmentsMemberato:MiscellaneousrevenueMemberato:DistributionSegmentMember2024-10-012025-09-300000731802us-gaap:OperatingSegmentsMemberato:MiscellaneousrevenueMemberato:PipelineandStorageSegmentMember2024-10-012025-09-300000731802us-gaap:OperatingSegmentsMemberato:GassalesrevenueMemberato:ResidentialCustomersMemberato:DistributionSegmentMember2023-10-012024-09-300000731802us-gaap:OperatingSegmentsMemberato:GassalesrevenueMemberato:ResidentialCustomersMemberato:PipelineandStorageSegmentMember2023-10-012024-09-300000731802us-gaap:OperatingSegmentsMemberato:GassalesrevenueMemberato:CommercialCustomersMemberato:DistributionSegmentMember2023-10-012024-09-300000731802us-gaap:OperatingSegmentsMemberato:GassalesrevenueMemberato:CommercialCustomersMemberato:PipelineandStorageSegmentMember2023-10-012024-09-300000731802us-gaap:OperatingSegmentsMemberato:GassalesrevenueMemberato:IndustrialCustomersMemberato:DistributionSegmentMember2023-10-012024-09-300000731802us-gaap:OperatingSegmentsMemberato:GassalesrevenueMemberato:IndustrialCustomersMemberato:PipelineandStorageSegmentMember2023-10-012024-09-300000731802us-gaap:OperatingSegmentsMemberato:GassalesrevenueMemberato:PublicAuthorityandOtherCustomersMemberato:DistributionSegmentMember2023-10-012024-09-300000731802us-gaap:OperatingSegmentsMemberato:GassalesrevenueMemberato:PublicAuthorityandOtherCustomersMemberato:PipelineandStorageSegmentMember2023-10-012024-09-300000731802us-gaap:OperatingSegmentsMemberato:GassalesrevenueMemberato:DistributionSegmentMember2023-10-012024-09-300000731802us-gaap:OperatingSegmentsMemberato:GassalesrevenueMemberato:PipelineandStorageSegmentMember2023-10-012024-09-300000731802us-gaap:OperatingSegmentsMemberato:TransportationrevenueMemberato:DistributionSegmentMember2023-10-012024-09-300000731802us-gaap:OperatingSegmentsMemberato:TransportationrevenueMemberato:PipelineandStorageSegmentMember2023-10-012024-09-300000731802us-gaap:OperatingSegmentsMemberato:MiscellaneousrevenueMemberato:DistributionSegmentMember2023-10-012024-09-300000731802us-gaap:OperatingSegmentsMemberato:MiscellaneousrevenueMemberato:PipelineandStorageSegmentMember2023-10-012024-09-300000731802us-gaap:OperatingSegmentsMemberato:GassalesrevenueMemberato:ResidentialCustomersMemberato:DistributionSegmentMember2022-10-012023-09-300000731802us-gaap:OperatingSegmentsMemberato:GassalesrevenueMemberato:ResidentialCustomersMemberato:PipelineandStorageSegmentMember2022-10-012023-09-300000731802us-gaap:OperatingSegmentsMemberato:GassalesrevenueMemberato:CommercialCustomersMemberato:DistributionSegmentMember2022-10-012023-09-300000731802us-gaap:OperatingSegmentsMemberato:GassalesrevenueMemberato:CommercialCustomersMemberato:PipelineandStorageSegmentMember2022-10-012023-09-300000731802us-gaap:OperatingSegmentsMemberato:GassalesrevenueMemberato:IndustrialCustomersMemberato:DistributionSegmentMember2022-10-012023-09-300000731802us-gaap:OperatingSegmentsMemberato:GassalesrevenueMemberato:IndustrialCustomersMemberato:PipelineandStorageSegmentMember2022-10-012023-09-300000731802us-gaap:OperatingSegmentsMemberato:GassalesrevenueMemberato:PublicAuthorityandOtherCustomersMemberato:DistributionSegmentMember2022-10-012023-09-300000731802us-gaap:OperatingSegmentsMemberato:GassalesrevenueMemberato:PublicAuthorityandOtherCustomersMemberato:PipelineandStorageSegmentMember2022-10-012023-09-300000731802us-gaap:OperatingSegmentsMemberato:GassalesrevenueMemberato:DistributionSegmentMember2022-10-012023-09-300000731802us-gaap:OperatingSegmentsMemberato:GassalesrevenueMemberato:PipelineandStorageSegmentMember2022-10-012023-09-300000731802us-gaap:OperatingSegmentsMemberato:TransportationrevenueMemberato:DistributionSegmentMember2022-10-012023-09-300000731802us-gaap:OperatingSegmentsMemberato:TransportationrevenueMemberato:PipelineandStorageSegmentMember2022-10-012023-09-300000731802us-gaap:OperatingSegmentsMemberato:MiscellaneousrevenueMemberato:DistributionSegmentMember2022-10-012023-09-300000731802us-gaap:OperatingSegmentsMemberato:MiscellaneousrevenueMemberato:PipelineandStorageSegmentMember2022-10-012023-09-300000731802ato:MississippiPublicServiceCommissionMember2023-12-310000731802ato:MississippiPublicServiceCommissionMember2023-11-300000731802ato:MississippiPublicServiceCommissionMember2023-10-012023-12-310000731802ato:MississippiPublicServiceCommissionMember2022-04-012025-09-300000731802ato:MississippiPublicServiceCommissionMember2024-10-012025-09-300000731802us-gaap:SubsequentEventMember2025-12-310000731802ato:Unsecured300SeniorNotesDueJune2027Member2025-09-300000731802ato:Unsecured300SeniorNotesDueJune2027Member2024-09-300000731802ato:Unsecured2625SeniorNotesDueSeptember2029Member2025-09-300000731802ato:Unsecured2625SeniorNotesDueSeptember2029Member2024-09-300000731802ato:Unsecured150SeniorNotesDueJanuary2031Member2025-09-300000731802ato:Unsecured150SeniorNotesDueJanuary2031Member2024-09-300000731802ato:Unsecured545SeniorNotesDueOctober2032Member2025-09-300000731802ato:Unsecured545SeniorNotesDueOctober2032Member2024-09-300000731802ato:Unsecured5.90SeniorNotesDueNovember2033Member2025-09-300000731802ato:Unsecured5.90SeniorNotesDueNovember2033Member2024-09-300000731802ato:Unsecured595SeniorNotesDueOctober2034Member2025-09-300000731802ato:Unsecured595SeniorNotesDueOctober2034Member2024-09-300000731802ato:Unsecured5.20SeniorNotesDueAugust2035Member2025-09-300000731802ato:Unsecured5.20SeniorNotesDueAugust2035Member2024-09-300000731802ato:Unsecured550SeniorNotesDueJune2041Member2025-09-300000731802ato:Unsecured550SeniorNotesDueJune2041Member2024-09-300000731802ato:Unsecured415SeniorNotesDueJanuary2043Member2025-09-300000731802ato:Unsecured415SeniorNotesDueJanuary2043Member2024-09-300000731802ato:Unsecured4125SeniorNotesDueOctober2044Member2025-09-300000731802ato:Unsecured4125SeniorNotesDueOctober2044Member2024-09-300000731802ato:Unsecured430SeniorNotesDueOctober2048Member2025-09-300000731802ato:Unsecured430SeniorNotesDueOctober2048Member2024-09-300000731802ato:Unsecured4125SeniorNotesDueMarch2049Member2025-09-300000731802ato:Unsecured4125SeniorNotesDueMarch2049Member2024-09-300000731802ato:Unsecured3375SeniorNotesDueSeptember2049Member2025-09-300000731802ato:Unsecured3375SeniorNotesDueSeptember2049Member2024-09-300000731802ato:Unsecured285SeniorNotesDueFebruary2052Member2025-09-300000731802ato:Unsecured285SeniorNotesDueFebruary2052Member2024-09-300000731802ato:Unsecured575SeniorNotesDueOctober2052Member2025-09-300000731802ato:Unsecured575SeniorNotesDueOctober2052Member2024-09-300000731802ato:Unsecured6.20SeniorNotesDueNovember2053Member2025-09-300000731802ato:Unsecured6.20SeniorNotesDueNovember2053Member2024-09-300000731802ato:Unsecured5.00SeniorNotesDueDecember2054Member2025-09-300000731802ato:Unsecured5.00SeniorNotesDueDecember2054Member2024-09-300000731802ato:MediumTermNoteSeriesA19951667DueDecember2025Member2025-09-300000731802ato:MediumTermNoteSeriesA19951667DueDecember2025Member2024-09-300000731802ato:Unsecured675DebenturesDueJuly2028Member2025-09-300000731802ato:Unsecured675DebenturesDueJuly2028Member2024-09-300000731802ato:Unsecured5.45SeniorNotesDueJanuary2056Memberus-gaap:SeniorNotesMemberus-gaap:SubsequentEventMember2025-10-010000731802ato:Unsecured5.45SeniorNotesDueJanuary2056Memberus-gaap:SeniorNotesMember2025-09-012025-09-300000731802us-gaap:SeniorNotesMember2025-09-012025-09-300000731802ato:Unsecured5.20SeniorNotesDueAugust2035Memberus-gaap:SeniorNotesMember2025-06-260000731802ato:Unsecured5.20SeniorNotesDueAugust2035Memberus-gaap:SeniorNotesMember2025-06-262025-06-260000731802ato:Unsecured5.00SeniorNotesDueDecember2054Memberus-gaap:SeniorNotesMember2024-10-010000731802ato:Unsecured5.00SeniorNotesDueDecember2054Memberus-gaap:SeniorNotesMember2024-10-012024-10-010000731802us-gaap:SeniorNotesMember2024-09-012024-09-300000731802ato:Unsecured5.90SeniorNotesDueNovember2033Memberus-gaap:SeniorNotesMember2024-06-210000731802ato:Unsecured5.90SeniorNotesDueNovember2033Memberus-gaap:SeniorNotesMember2024-06-212024-06-210000731802ato:Unsecured6.20SeniorNotesDueNovember2053Memberus-gaap:SeniorNotesMember2023-10-100000731802ato:Unsecured5.90SeniorNotesDueNovember2033Memberus-gaap:SeniorNotesMember2023-10-100000731802ato:UnsecuredSeniorNotesDue2033AndUnsecuredSeniorNotesDue2053Memberus-gaap:SeniorNotesMember2023-10-102023-10-100000731802us-gaap:SeniorNotesMember2023-09-012023-09-300000731802us-gaap:CommercialPaperMemberato:FiveYearUnsecuredRevolvingCreditAgreementMaturingOnMarch282029Member2025-09-300000731802us-gaap:RevolvingCreditFacilityMemberato:FiveYearUnsecuredRevolvingCreditAgreementMaturingOnMarch282029Member2025-09-300000731802us-gaap:CommercialPaperMemberato:FiveYearUnsecuredRevolvingCreditAgreementMember2024-03-272024-03-270000731802us-gaap:CommercialPaperMemberato:FiveYearUnsecuredRevolvingCreditAgreementMember2024-03-270000731802us-gaap:BaseRateMemberato:FiveYearUnsecuredRevolvingCreditAgreementMaturingOnMarch282029Membersrt:MinimumMember2024-10-012025-09-300000731802us-gaap:BaseRateMemberato:FiveYearUnsecuredRevolvingCreditAgreementMaturingOnMarch282029Membersrt:MaximumMember2024-10-012025-09-300000731802us-gaap:SecuredOvernightFinancingRateSofrMemberato:FiveYearUnsecuredRevolvingCreditAgreementMaturingOnMarch282029Membersrt:MinimumMember2024-10-012025-09-300000731802us-gaap:SecuredOvernightFinancingRateSofrMemberato:FiveYearUnsecuredRevolvingCreditAgreementMaturingOnMarch282029Membersrt:MaximumMember2024-10-012025-09-300000731802ato:FiveYearUnsecuredRevolvingCreditAgreementMember2025-09-300000731802us-gaap:RevolvingCreditFacilityMemberato:A1.5BillionRevolvingCreditFacilityMember2024-03-280000731802us-gaap:RevolvingCreditFacilityMemberato:A1.5BillionRevolvingCreditFacilityMember2024-03-282024-03-280000731802us-gaap:RevolvingCreditFacilityMemberus-gaap:BaseRateMemberato:A1.5BillionRevolvingCreditFacilityMembersrt:MinimumMember2024-10-012025-09-300000731802us-gaap:RevolvingCreditFacilityMemberus-gaap:BaseRateMemberato:A1.5BillionRevolvingCreditFacilityMembersrt:MaximumMember2024-10-012025-09-300000731802us-gaap:RevolvingCreditFacilityMemberus-gaap:SecuredOvernightFinancingRateSofrMemberato:A1.5BillionRevolvingCreditFacilityMembersrt:MinimumMember2024-10-012025-09-300000731802us-gaap:RevolvingCreditFacilityMemberus-gaap:SecuredOvernightFinancingRateSofrMemberato:A1.5BillionRevolvingCreditFacilityMembersrt:MaximumMember2024-10-012025-09-300000731802us-gaap:RevolvingCreditFacilityMemberato:A900MillionRevolvingCreditFacilityMember2024-09-300000731802us-gaap:RevolvingCreditFacilityMemberato:A1.5BillionRevolvingCreditFacilityMember2025-09-300000731802us-gaap:RevolvingCreditFacilityMemberato:A900MillionRevolvingCreditFacilityMember2025-09-300000731802us-gaap:RevolvingCreditFacilityMemberato:A1.5BillionRevolvingCreditFacilityMember2024-09-300000731802us-gaap:LineOfCreditMemberato:A50MillionBankLoanAgreementMember2025-04-010000731802us-gaap:LineOfCreditMemberato:A50MillionBankLoanAgreementMember2025-04-012025-04-010000731802us-gaap:LineOfCreditMemberato:A50MillionBankLoanAgreementMember2025-09-300000731802us-gaap:LineOfCreditMemberato:A50MillionBankLoanAgreementMember2024-09-300000731802us-gaap:RevolvingCreditFacilityMemberato:A50MillionRevolvingCreditFacilityMember2025-03-310000731802us-gaap:RevolvingCreditFacilityMemberato:A50MillionRevolvingCreditFacilityMember2025-03-312025-03-310000731802us-gaap:RevolvingCreditFacilityMemberato:A50MillionRevolvingCreditFacilityMember2025-09-300000731802srt:MinimumMember2025-09-300000731802srt:MaximumMember2025-09-300000731802ato:ShelfRegistrationStatementMember2024-12-030000731802ato:ShelfRegistrationStatementMemberus-gaap:SubsequentEventMember2025-11-140000731802ato:AtTheMarketMember2024-12-030000731802ato:AtTheMarketMember2024-10-012025-09-300000731802ato:AtTheMarketMember2025-09-300000731802ato:ForwardSalesEquityAgreementMaturingQuarterEndedDecember312025Member2025-09-300000731802ato:ForwardSalesEquityAgreementMaturingQuarterEndedDecember312025Member2024-10-012025-09-300000731802ato:ForwardSalesEquityAgreementMaturingQuarterEndedMarch312026Member2025-09-300000731802ato:ForwardSalesEquityAgreementMaturingQuarterEndedMarch312026Member2024-10-012025-09-300000731802ato:ForwardSalesEquityAgreementMaturingQuarterEndedJune302026Member2025-09-300000731802ato:ForwardSalesEquityAgreementMaturingQuarterEndedJune302026Member2024-10-012025-09-300000731802ato:ForwardSalesEquityAgreementMaturingQuarterEndedDecember312026Member2025-09-300000731802ato:ForwardSalesEquityAgreementMaturingQuarterEndedDecember312026Member2024-10-012025-09-300000731802ato:ForwardSalesEquityAgreementMaturingQuarterEndedMarch312027Member2025-09-300000731802ato:ForwardSalesEquityAgreementMaturingQuarterEndedMarch312027Member2024-10-012025-09-300000731802us-gaap:AccumulatedNetUnrealizedInvestmentGainLossMember2024-09-300000731802us-gaap:AccumulatedGainLossNetCashFlowHedgeParentMember2024-09-300000731802us-gaap:AccumulatedNetUnrealizedInvestmentGainLossMember2024-10-012025-09-300000731802us-gaap:AccumulatedGainLossNetCashFlowHedgeParentMember2024-10-012025-09-300000731802us-gaap:AccumulatedNetUnrealizedInvestmentGainLossMember2025-09-300000731802us-gaap:AccumulatedGainLossNetCashFlowHedgeParentMember2025-09-300000731802us-gaap:AccumulatedNetUnrealizedInvestmentGainLossMember2023-09-300000731802us-gaap:AccumulatedGainLossNetCashFlowHedgeParentMember2023-09-300000731802us-gaap:AccumulatedNetUnrealizedInvestmentGainLossMember2023-10-012024-09-300000731802us-gaap:AccumulatedGainLossNetCashFlowHedgeParentMember2023-10-012024-09-300000731802us-gaap:VariableInterestEntityPrimaryBeneficiaryMemberato:Series2023ASeniorSecuredSecuritizedUtilityTariffBondsDueMarch2033Memberus-gaap:SeniorNotesMember2023-06-300000731802us-gaap:VariableInterestEntityPrimaryBeneficiaryMemberato:Series2023ASeniorSecuredSecuritizedUtilityTariffBondsDueMarch2033Memberus-gaap:SeniorNotesMember2023-06-012023-06-300000731802ato:SecuritizedUtilityTariffPropertyMemberus-gaap:VariableInterestEntityPrimaryBeneficiaryMember2023-06-012023-06-300000731802ato:SecuritizedUtilityTariffPropertyMemberus-gaap:VariableInterestEntityPrimaryBeneficiaryMember2023-06-300000731802ato:SecuritizedUtilityTariffPropertyMemberus-gaap:VariableInterestEntityPrimaryBeneficiaryMember2025-09-300000731802us-gaap:VariableInterestEntityPrimaryBeneficiaryMember2025-09-300000731802us-gaap:VariableInterestEntityPrimaryBeneficiaryMember2024-09-300000731802us-gaap:VariableInterestEntityPrimaryBeneficiaryMember2024-10-012025-09-300000731802us-gaap:VariableInterestEntityPrimaryBeneficiaryMember2023-10-012024-09-300000731802us-gaap:VariableInterestEntityPrimaryBeneficiaryMember2022-10-012023-09-300000731802us-gaap:VariableInterestEntityPrimaryBeneficiaryMemberato:Series2023ASeniorSecuredSecuritizedUtilityTariffBondsDueMarch2033Memberus-gaap:SeniorNotesMember2025-09-300000731802us-gaap:VariableInterestEntityPrimaryBeneficiaryMemberato:Series2023ASeniorSecuredSecuritizedUtilityTariffBondsDueMarch2033Memberus-gaap:SeniorNotesMember2024-09-300000731802stpr:TXato:WinterStormUriMemberus-gaap:AssetRecoverableGasCostsMember2023-03-310000731802stpr:TXsrt:MinimumMemberato:WinterStormUriMemberus-gaap:AssetRecoverableGasCostsMember2023-03-012023-03-310000731802stpr:TXsrt:MaximumMemberato:WinterStormUriMemberus-gaap:AssetRecoverableGasCostsMember2023-03-012023-03-310000731802stpr:TXato:WinterStormUriMemberus-gaap:AssetRecoverableGasCostsMember2023-03-012023-03-310000731802ato:UnrecognizedPriorServiceCreditMemberus-gaap:PensionPlansDefinedBenefitMember2025-09-300000731802ato:UnrecognizedPriorServiceCreditMemberus-gaap:SupplementalEmployeeRetirementPlanDefinedBenefitMember2025-09-300000731802ato:UnrecognizedPriorServiceCreditMemberus-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember2025-09-300000731802ato:UnrecognizedPriorServiceCreditMember2025-09-300000731802ato:UnrecognizedActuarialGainLossMemberus-gaap:PensionPlansDefinedBenefitMember2025-09-300000731802ato:UnrecognizedActuarialGainLossMemberus-gaap:SupplementalEmployeeRetirementPlanDefinedBenefitMember2025-09-300000731802ato:UnrecognizedActuarialGainLossMemberus-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember2025-09-300000731802ato:UnrecognizedActuarialGainLossMember2025-09-300000731802ato:TotalUnrecognizedinNetPeriodicPensionCostMemberus-gaap:PensionPlansDefinedBenefitMember2025-09-300000731802ato:TotalUnrecognizedinNetPeriodicPensionCostMemberus-gaap:SupplementalEmployeeRetirementPlanDefinedBenefitMember2025-09-300000731802ato:TotalUnrecognizedinNetPeriodicPensionCostMemberus-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember2025-09-300000731802ato:TotalUnrecognizedinNetPeriodicPensionCostMemberus-gaap:PensionAndOtherPostretirementPlansCostsMember2025-09-300000731802ato:UnrecognizedPriorServiceCreditMemberus-gaap:PensionPlansDefinedBenefitMember2024-09-300000731802ato:UnrecognizedPriorServiceCreditMemberus-gaap:SupplementalEmployeeRetirementPlanDefinedBenefitMember2024-09-300000731802ato:UnrecognizedPriorServiceCreditMemberus-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember2024-09-300000731802ato:UnrecognizedPriorServiceCreditMember2024-09-300000731802ato:UnrecognizedActuarialGainLossMemberus-gaap:PensionPlansDefinedBenefitMember2024-09-300000731802ato:UnrecognizedActuarialGainLossMemberus-gaap:SupplementalEmployeeRetirementPlanDefinedBenefitMember2024-09-300000731802ato:UnrecognizedActuarialGainLossMemberus-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember2024-09-300000731802ato:UnrecognizedActuarialGainLossMember2024-09-300000731802ato:TotalUnrecognizedinNetPeriodicPensionCostMemberus-gaap:PensionPlansDefinedBenefitMember2024-09-300000731802ato:TotalUnrecognizedinNetPeriodicPensionCostMemberus-gaap:SupplementalEmployeeRetirementPlanDefinedBenefitMember2024-09-300000731802ato:TotalUnrecognizedinNetPeriodicPensionCostMemberus-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember2024-09-300000731802ato:TotalUnrecognizedinNetPeriodicPensionCostMemberus-gaap:PensionAndOtherPostretirementPlansCostsMember2024-09-300000731802us-gaap:PensionPlansDefinedBenefitMember2024-10-012025-09-300000731802us-gaap:PensionPlansDefinedBenefitMember2023-10-012024-09-300000731802srt:MinimumMemberus-gaap:PensionPlansDefinedBenefitMember2024-10-012025-09-300000731802srt:MaximumMemberus-gaap:PensionPlansDefinedBenefitMember2024-10-012025-09-300000731802us-gaap:PensionPlansDefinedBenefitMembersrt:MinimumMemberato:DomesticEquitySecuritiesMember2025-09-300000731802us-gaap:PensionPlansDefinedBenefitMembersrt:MaximumMemberato:DomesticEquitySecuritiesMember2025-09-300000731802ato:DomesticEquitySecuritiesMemberus-gaap:PensionPlansDefinedBenefitMember2025-09-300000731802ato:DomesticEquitySecuritiesMemberus-gaap:PensionPlansDefinedBenefitMember2024-09-300000731802us-gaap:PensionPlansDefinedBenefitMembersrt:MinimumMemberato:InternationalEquitySecuritiesMember2025-09-300000731802us-gaap:PensionPlansDefinedBenefitMembersrt:MaximumMemberato:InternationalEquitySecuritiesMember2025-09-300000731802ato:InternationalEquitySecuritiesMemberus-gaap:PensionPlansDefinedBenefitMember2025-09-300000731802ato:InternationalEquitySecuritiesMemberus-gaap:PensionPlansDefinedBenefitMember2024-09-300000731802us-gaap:PensionPlansDefinedBenefitMembersrt:MinimumMemberus-gaap:FixedIncomeSecuritiesMember2025-09-300000731802us-gaap:PensionPlansDefinedBenefitMembersrt:MaximumMemberus-gaap:FixedIncomeSecuritiesMember2025-09-300000731802us-gaap:FixedIncomeSecuritiesMemberus-gaap:PensionPlansDefinedBenefitMember2025-09-300000731802us-gaap:FixedIncomeSecuritiesMemberus-gaap:PensionPlansDefinedBenefitMember2024-09-300000731802us-gaap:PensionPlansDefinedBenefitMembersrt:MinimumMemberato:CompanyStockMember2025-09-300000731802us-gaap:PensionPlansDefinedBenefitMembersrt:MaximumMemberato:CompanyStockMember2025-09-300000731802ato:CompanyStockMemberus-gaap:PensionPlansDefinedBenefitMember2025-09-300000731802ato:CompanyStockMemberus-gaap:PensionPlansDefinedBenefitMember2024-09-300000731802us-gaap:PensionPlansDefinedBenefitMembersrt:MinimumMemberato:OtherInvestmentAssetsMember2025-09-300000731802us-gaap:PensionPlansDefinedBenefitMembersrt:MaximumMemberato:OtherInvestmentAssetsMember2025-09-300000731802ato:OtherInvestmentAssetsMemberus-gaap:PensionPlansDefinedBenefitMember2025-09-300000731802ato:OtherInvestmentAssetsMemberus-gaap:PensionPlansDefinedBenefitMember2024-09-300000731802us-gaap:PensionPlansDefinedBenefitMember2025-09-300000731802us-gaap:PensionPlansDefinedBenefitMember2024-09-300000731802us-gaap:PensionPlansDefinedBenefitMember2022-10-012023-09-300000731802srt:ScenarioForecastMemberus-gaap:PensionPlansDefinedBenefitMember2026-09-300000731802srt:ScenarioForecastMemberus-gaap:PensionPlansDefinedBenefitMember2026-10-010000731802us-gaap:PensionPlansDefinedBenefitMember2023-09-300000731802us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel1Memberus-gaap:PensionPlansDefinedBenefitMemberus-gaap:EquitySecuritiesMember2025-09-300000731802us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel2Memberus-gaap:PensionPlansDefinedBenefitMemberus-gaap:EquitySecuritiesMember2025-09-300000731802us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel3Memberus-gaap:PensionPlansDefinedBenefitMemberus-gaap:EquitySecuritiesMember2025-09-300000731802us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel12And3Memberus-gaap:PensionPlansDefinedBenefitMemberus-gaap:EquitySecuritiesMember2025-09-300000731802us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel1Memberus-gaap:PensionPlansDefinedBenefitMemberus-gaap:MoneyMarketFundsMember2025-09-300000731802us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel2Memberus-gaap:PensionPlansDefinedBenefitMemberus-gaap:MoneyMarketFundsMember2025-09-300000731802us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel3Memberus-gaap:PensionPlansDefinedBenefitMemberus-gaap:MoneyMarketFundsMember2025-09-300000731802us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel12And3Memberus-gaap:PensionPlansDefinedBenefitMemberus-gaap:MoneyMarketFundsMember2025-09-300000731802us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel1Memberus-gaap:PensionPlansDefinedBenefitMemberus-gaap:MutualFundMember2025-09-300000731802us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel2Memberus-gaap:PensionPlansDefinedBenefitMemberus-gaap:MutualFundMember2025-09-300000731802us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel3Memberus-gaap:PensionPlansDefinedBenefitMemberus-gaap:MutualFundMember2025-09-300000731802us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel12And3Memberus-gaap:PensionPlansDefinedBenefitMemberus-gaap:MutualFundMember2025-09-300000731802us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel1Memberus-gaap:PensionPlansDefinedBenefitMemberus-gaap:USGovernmentSponsoredEnterprisesDebtSecuritiesMember2025-09-300000731802us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel2Memberus-gaap:PensionPlansDefinedBenefitMemberus-gaap:USGovernmentSponsoredEnterprisesDebtSecuritiesMember2025-09-300000731802us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel3Memberus-gaap:PensionPlansDefinedBenefitMemberus-gaap:USGovernmentSponsoredEnterprisesDebtSecuritiesMember2025-09-300000731802us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel12And3Memberus-gaap:PensionPlansDefinedBenefitMemberus-gaap:USGovernmentSponsoredEnterprisesDebtSecuritiesMember2025-09-300000731802us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel1Memberus-gaap:PensionPlansDefinedBenefitMemberus-gaap:USTreasurySecuritiesMember2025-09-300000731802us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel2Memberus-gaap:PensionPlansDefinedBenefitMemberus-gaap:USTreasurySecuritiesMember2025-09-300000731802us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel3Memberus-gaap:PensionPlansDefinedBenefitMemberus-gaap:USTreasurySecuritiesMember2025-09-300000731802us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel12And3Memberus-gaap:PensionPlansDefinedBenefitMemberus-gaap:USTreasurySecuritiesMember2025-09-300000731802us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel1Memberus-gaap:PensionPlansDefinedBenefitMemberus-gaap:CorporateDebtSecuritiesMember2025-09-300000731802us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel2Memberus-gaap:PensionPlansDefinedBenefitMemberus-gaap:CorporateDebtSecuritiesMember2025-09-300000731802us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel3Memberus-gaap:PensionPlansDefinedBenefitMemberus-gaap:CorporateDebtSecuritiesMember2025-09-300000731802us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel12And3Memberus-gaap:PensionPlansDefinedBenefitMemberus-gaap:CorporateDebtSecuritiesMember2025-09-300000731802us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel1Memberus-gaap:PensionPlansDefinedBenefitMemberus-gaap:AssetBackedSecuritiesMember2025-09-300000731802us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel2Memberus-gaap:PensionPlansDefinedBenefitMemberus-gaap:AssetBackedSecuritiesMember2025-09-300000731802us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel3Memberus-gaap:PensionPlansDefinedBenefitMemberus-gaap:AssetBackedSecuritiesMember2025-09-300000731802us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel12And3Memberus-gaap:PensionPlansDefinedBenefitMemberus-gaap:AssetBackedSecuritiesMember2025-09-300000731802us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel1Memberus-gaap:PensionPlansDefinedBenefitMember2025-09-300000731802us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel2Memberus-gaap:PensionPlansDefinedBenefitMember2025-09-300000731802us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel3Memberus-gaap:PensionPlansDefinedBenefitMember2025-09-300000731802us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel12And3Memberus-gaap:PensionPlansDefinedBenefitMember2025-09-300000731802us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueMeasuredAtNetAssetValuePerShareMemberus-gaap:PensionPlansDefinedBenefitMemberato:CommonCollectiveTrustsMember2025-09-300000731802us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueMeasuredAtNetAssetValuePerShareMemberus-gaap:PensionPlansDefinedBenefitMemberato:LimitedPartnershipInterestMember2025-09-300000731802us-gaap:FairValueMeasurementsRecurringMemberus-gaap:PensionPlansDefinedBenefitMember2025-09-300000731802us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel1Memberus-gaap:PensionPlansDefinedBenefitMemberus-gaap:EquitySecuritiesMember2024-09-300000731802us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel2Memberus-gaap:PensionPlansDefinedBenefitMemberus-gaap:EquitySecuritiesMember2024-09-300000731802us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel3Memberus-gaap:PensionPlansDefinedBenefitMemberus-gaap:EquitySecuritiesMember2024-09-300000731802us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel12And3Memberus-gaap:PensionPlansDefinedBenefitMemberus-gaap:EquitySecuritiesMember2024-09-300000731802us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel1Memberus-gaap:PensionPlansDefinedBenefitMemberus-gaap:MoneyMarketFundsMember2024-09-300000731802us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel2Memberus-gaap:PensionPlansDefinedBenefitMemberus-gaap:MoneyMarketFundsMember2024-09-300000731802us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel3Memberus-gaap:PensionPlansDefinedBenefitMemberus-gaap:MoneyMarketFundsMember2024-09-300000731802us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel12And3Memberus-gaap:PensionPlansDefinedBenefitMemberus-gaap:MoneyMarketFundsMember2024-09-300000731802us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel1Memberus-gaap:PensionPlansDefinedBenefitMemberus-gaap:MutualFundMember2024-09-300000731802us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel2Memberus-gaap:PensionPlansDefinedBenefitMemberus-gaap:MutualFundMember2024-09-300000731802us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel3Memberus-gaap:PensionPlansDefinedBenefitMemberus-gaap:MutualFundMember2024-09-300000731802us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel12And3Memberus-gaap:PensionPlansDefinedBenefitMemberus-gaap:MutualFundMember2024-09-300000731802us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel1Memberus-gaap:PensionPlansDefinedBenefitMemberus-gaap:USGovernmentSponsoredEnterprisesDebtSecuritiesMember2024-09-300000731802us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel2Memberus-gaap:PensionPlansDefinedBenefitMemberus-gaap:USGovernmentSponsoredEnterprisesDebtSecuritiesMember2024-09-300000731802us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel3Memberus-gaap:PensionPlansDefinedBenefitMemberus-gaap:USGovernmentSponsoredEnterprisesDebtSecuritiesMember2024-09-300000731802us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel12And3Memberus-gaap:PensionPlansDefinedBenefitMemberus-gaap:USGovernmentSponsoredEnterprisesDebtSecuritiesMember2024-09-300000731802us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel1Memberus-gaap:PensionPlansDefinedBenefitMemberus-gaap:USTreasurySecuritiesMember2024-09-300000731802us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel2Memberus-gaap:PensionPlansDefinedBenefitMemberus-gaap:USTreasurySecuritiesMember2024-09-300000731802us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel3Memberus-gaap:PensionPlansDefinedBenefitMemberus-gaap:USTreasurySecuritiesMember2024-09-300000731802us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel12And3Memberus-gaap:PensionPlansDefinedBenefitMemberus-gaap:USTreasurySecuritiesMember2024-09-300000731802us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel1Memberus-gaap:PensionPlansDefinedBenefitMemberus-gaap:CorporateDebtSecuritiesMember2024-09-300000731802us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel2Memberus-gaap:PensionPlansDefinedBenefitMemberus-gaap:CorporateDebtSecuritiesMember2024-09-300000731802us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel3Memberus-gaap:PensionPlansDefinedBenefitMemberus-gaap:CorporateDebtSecuritiesMember2024-09-300000731802us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel12And3Memberus-gaap:PensionPlansDefinedBenefitMemberus-gaap:CorporateDebtSecuritiesMember2024-09-300000731802us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel1Memberus-gaap:PensionPlansDefinedBenefitMember2024-09-300000731802us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel2Memberus-gaap:PensionPlansDefinedBenefitMember2024-09-300000731802us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel3Memberus-gaap:PensionPlansDefinedBenefitMember2024-09-300000731802us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel12And3Memberus-gaap:PensionPlansDefinedBenefitMember2024-09-300000731802us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueMeasuredAtNetAssetValuePerShareMemberus-gaap:PensionPlansDefinedBenefitMemberato:CommonCollectiveTrustsMember2024-09-300000731802us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueMeasuredAtNetAssetValuePerShareMemberus-gaap:PensionPlansDefinedBenefitMemberato:LimitedPartnershipInterestMember2024-09-300000731802us-gaap:FairValueMeasurementsRecurringMemberus-gaap:PensionPlansDefinedBenefitMember2024-09-300000731802ato:SupplementalExecutiveBenefitPlanMember2025-09-300000731802ato:SupplementalExecutiveBenefitPlanMemberus-gaap:SupplementalEmployeeRetirementPlanDefinedBenefitMember2024-10-012025-09-300000731802ato:A1998SupplementalExecutiveRetirementPlanMemberus-gaap:SupplementalEmployeeRetirementPlanDefinedBenefitMember2024-10-012025-09-300000731802ato:A2009SupplementalExecutiveRetirementPlanDefinedBenefitMemberus-gaap:SupplementalEmployeeRetirementPlanDefinedBenefitMember2024-10-012025-09-300000731802srt:ExecutiveOfficerMemberus-gaap:SupplementalEmployeeRetirementPlanDefinedBenefitMember2023-10-012024-09-300000731802srt:ExecutiveOfficerMemberus-gaap:SupplementalEmployeeRetirementPlanDefinedBenefitMember2022-10-012023-09-300000731802us-gaap:SupplementalEmployeeRetirementPlanDefinedBenefitMember2025-09-300000731802us-gaap:SupplementalEmployeeRetirementPlanDefinedBenefitMember2024-09-300000731802us-gaap:SupplementalEmployeeRetirementPlanDefinedBenefitMember2024-10-012025-09-300000731802us-gaap:SupplementalEmployeeRetirementPlanDefinedBenefitMember2023-10-012024-09-300000731802us-gaap:SupplementalEmployeeRetirementPlanDefinedBenefitMember2022-10-012023-09-300000731802srt:ScenarioForecastMemberus-gaap:SupplementalEmployeeRetirementPlanDefinedBenefitMember2026-09-300000731802srt:ScenarioForecastMemberus-gaap:SupplementalEmployeeRetirementPlanDefinedBenefitMember2026-10-010000731802us-gaap:SupplementalEmployeeRetirementPlanDefinedBenefitMember2023-09-300000731802srt:MinimumMemberus-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember2025-09-300000731802srt:MaximumMemberus-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember2025-09-300000731802ato:DiversifiedInvestmentFundsMemberus-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember2024-10-012025-09-300000731802ato:DiversifiedInvestmentFundsMemberus-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember2025-09-300000731802ato:DiversifiedInvestmentFundsMemberus-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember2024-09-300000731802us-gaap:DefinedBenefitPlanCashAndCashEquivalentsMemberus-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember2025-09-300000731802us-gaap:DefinedBenefitPlanCashAndCashEquivalentsMemberus-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember2024-09-300000731802us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember2025-09-300000731802us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember2024-09-300000731802us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember2024-10-012025-09-300000731802us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember2023-10-012024-09-300000731802us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember2022-10-012023-09-300000731802us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember2023-09-300000731802us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel1Memberus-gaap:OtherPostretirementBenefitPlansDefinedBenefitMemberus-gaap:MoneyMarketFundsMember2025-09-300000731802us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel2Memberus-gaap:OtherPostretirementBenefitPlansDefinedBenefitMemberus-gaap:MoneyMarketFundsMember2025-09-300000731802us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel3Memberus-gaap:OtherPostretirementBenefitPlansDefinedBenefitMemberus-gaap:MoneyMarketFundsMember2025-09-300000731802us-gaap:FairValueMeasurementsRecurringMemberus-gaap:OtherPostretirementBenefitPlansDefinedBenefitMemberus-gaap:MoneyMarketFundsMember2025-09-300000731802us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel1Memberus-gaap:OtherPostretirementBenefitPlansDefinedBenefitMemberus-gaap:MutualFundMember2025-09-300000731802us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel2Memberus-gaap:OtherPostretirementBenefitPlansDefinedBenefitMemberus-gaap:MutualFundMember2025-09-300000731802us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel3Memberus-gaap:OtherPostretirementBenefitPlansDefinedBenefitMemberus-gaap:MutualFundMember2025-09-300000731802us-gaap:FairValueMeasurementsRecurringMemberus-gaap:OtherPostretirementBenefitPlansDefinedBenefitMemberus-gaap:MutualFundMember2025-09-300000731802us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel1Memberus-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember2025-09-300000731802us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel2Memberus-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember2025-09-300000731802us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel3Memberus-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember2025-09-300000731802us-gaap:FairValueMeasurementsRecurringMemberus-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember2025-09-300000731802us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel1Memberus-gaap:OtherPostretirementBenefitPlansDefinedBenefitMemberus-gaap:MoneyMarketFundsMember2024-09-300000731802us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel2Memberus-gaap:OtherPostretirementBenefitPlansDefinedBenefitMemberus-gaap:MoneyMarketFundsMember2024-09-300000731802us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel3Memberus-gaap:OtherPostretirementBenefitPlansDefinedBenefitMemberus-gaap:MoneyMarketFundsMember2024-09-300000731802us-gaap:FairValueMeasurementsRecurringMemberus-gaap:OtherPostretirementBenefitPlansDefinedBenefitMemberus-gaap:MoneyMarketFundsMember2024-09-300000731802us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel1Memberus-gaap:OtherPostretirementBenefitPlansDefinedBenefitMemberus-gaap:MutualFundMember2024-09-300000731802us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel2Memberus-gaap:OtherPostretirementBenefitPlansDefinedBenefitMemberus-gaap:MutualFundMember2024-09-300000731802us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel3Memberus-gaap:OtherPostretirementBenefitPlansDefinedBenefitMemberus-gaap:MutualFundMember2024-09-300000731802us-gaap:FairValueMeasurementsRecurringMemberus-gaap:OtherPostretirementBenefitPlansDefinedBenefitMemberus-gaap:MutualFundMember2024-09-300000731802us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel1Memberus-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember2024-09-300000731802us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel2Memberus-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember2024-09-300000731802us-gaap:FairValueMeasurementsRecurringMemberus-gaap:FairValueInputsLevel3Memberus-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember2024-09-300000731802us-gaap:FairValueMeasurementsRecurringMemberus-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember2024-09-300000731802ato:RetirementSavingsPlanMember2024-10-012025-09-300000731802ato:RetirementSavingsPlanMemberus-gaap:PensionPlansDefinedBenefitMember2024-10-012025-09-300000731802srt:ScenarioForecastMemberato:RetirementSavingsPlanMember2026-01-012026-01-010000731802ato:RetirementSavingsPlanMember2023-10-012024-09-300000731802ato:RetirementSavingsPlanMember2022-10-012023-09-300000731802ato:RetirementSavingsPlanMember2025-09-300000731802ato:RetirementSavingsPlanMember2024-09-300000731802us-gaap:TradeAccountsReceivableMemberus-gaap:BilledRevenuesMember2025-09-300000731802us-gaap:TradeAccountsReceivableMemberus-gaap:BilledRevenuesMember2024-09-300000731802us-gaap:TradeAccountsReceivableMemberus-gaap:UnbilledRevenuesMember2025-09-300000731802us-gaap:TradeAccountsReceivableMemberus-gaap:UnbilledRevenuesMember2024-09-300000731802ato:InsuranceReceivableMember2025-09-300000731802ato:InsuranceReceivableMember2024-09-300000731802ato:OtherAccountsReceivableMember2025-09-300000731802ato:OtherAccountsReceivableMember2024-09-300000731802stpr:TX2024-10-012025-09-300000731802stpr:TX2023-10-012024-09-300000731802stpr:TX2022-10-012023-09-300000731802stpr:LA2024-10-012025-09-300000731802stpr:LA2023-10-012024-09-300000731802stpr:LA2022-10-012023-09-300000731802ato:OtherStatesMember2024-10-012025-09-300000731802ato:OtherStatesMember2023-10-012024-09-300000731802ato:OtherStatesMember2022-10-012023-09-300000731802ato:JacksonMississippiMemberato:NationalTransportationSafetyBoardMember2024-01-242024-01-270000731802ato:NationalTransportationSafetyBoardMember2024-01-270000731802ato:NationalTransportationSafetyBoardMember2024-12-020000731802us-gaap:SupplyCommitmentMember2024-10-012025-09-300000731802us-gaap:ShortTermContractWithCustomerMemberus-gaap:SupplyCommitmentMember2024-10-012025-09-300000731802ato:LongtermContractwithCustomerWithinTwoToThreeYearsMemberus-gaap:SupplyCommitmentMember2024-10-012025-09-300000731802ato:LongtermContractwithCustomerWithinTwoToThreeYearsMembersrt:MinimumMemberus-gaap:SupplyCommitmentMember2024-10-012025-09-300000731802ato:LongtermContractwithCustomerWithinTwoToThreeYearsMembersrt:MaximumMemberus-gaap:SupplyCommitmentMember2024-10-012025-09-300000731802srt:WeightedAverageMemberus-gaap:SupplyCommitmentMember2024-10-012025-09-300000731802us-gaap:DomesticCountryMember2025-09-300000731802us-gaap:StateAndLocalJurisdictionMember2025-09-300000731802us-gaap:OtherCurrentLiabilitiesMemberus-gaap:DeferredIncomeTaxChargesMember2025-09-300000731802us-gaap:OtherCurrentLiabilitiesMemberus-gaap:DeferredIncomeTaxChargesMember2024-09-300000731802ato:RegulatoryExcessDeferredTaxesToBeReturnedTrancheOneMember2025-09-300000731802srt:MinimumMemberato:RegulatoryExcessDeferredTaxesToBeReturnedTrancheOneMember2024-10-012025-09-300000731802srt:MaximumMemberato:RegulatoryExcessDeferredTaxesToBeReturnedTrancheOneMember2024-10-012025-09-300000731802ato:RegulatoryExcessDeferredTaxesToBeReturnedTrancheTwoMember2025-09-300000731802srt:MinimumMemberato:RegulatoryExcessDeferredTaxesToBeReturnedTrancheTwoMember2024-10-012025-09-300000731802srt:MaximumMemberato:RegulatoryExcessDeferredTaxesToBeReturnedTrancheTwoMember2024-10-012025-09-300000731802ato:RegulatoryExcessDeferredTaxesToBeReturnedTrancheThreeMember2025-09-300000731802us-gaap:CommodityContractMemberus-gaap:NondesignatedMemberato:GasPurchasesMembersrt:MinimumMember2025-09-300000731802us-gaap:CommodityContractMemberus-gaap:NondesignatedMemberato:GasPurchasesMembersrt:MaximumMember2025-09-300000731802us-gaap:CommodityContractMemberus-gaap:NondesignatedMemberato:GasPurchasesMember2024-10-012025-09-300000731802us-gaap:CommodityContractMemberus-gaap:NondesignatedMemberato:GasPurchasesMembersrt:WeightedAverageMember2024-10-012025-09-300000731802us-gaap:CommodityContractMemberus-gaap:OtherCurrentAssetsMemberus-gaap:NondesignatedMember2025-09-300000731802us-gaap:CommodityContractMemberus-gaap:OtherCurrentLiabilitiesMemberus-gaap:NondesignatedMember2025-09-300000731802us-gaap:CommodityContractMemberus-gaap:OtherNoncurrentAssetsMemberus-gaap:NondesignatedMember2025-09-300000731802us-gaap:CommodityContractMemberus-gaap:OtherNoncurrentLiabilitiesMemberus-gaap:NondesignatedMember2025-09-300000731802us-gaap:NondesignatedMember2025-09-300000731802us-gaap:InterestRateContractMemberus-gaap:OtherNoncurrentAssetsMemberus-gaap:DesignatedAsHedgingInstrumentMember2024-09-300000731802us-gaap:InterestRateContractMemberus-gaap:OtherNoncurrentLiabilitiesMemberus-gaap:DesignatedAsHedgingInstrumentMember2024-09-300000731802us-gaap:DesignatedAsHedgingInstrumentMember2024-09-300000731802us-gaap:CommodityContractMemberus-gaap:OtherCurrentAssetsMemberus-gaap:NondesignatedMember2024-09-300000731802us-gaap:CommodityContractMemberus-gaap:OtherCurrentLiabilitiesMemberus-gaap:NondesignatedMember2024-09-300000731802us-gaap:CommodityContractMemberus-gaap:OtherNoncurrentAssetsMemberus-gaap:NondesignatedMember2024-09-300000731802us-gaap:CommodityContractMemberus-gaap:OtherNoncurrentLiabilitiesMemberus-gaap:NondesignatedMember2024-09-300000731802us-gaap:NondesignatedMember2024-09-300000731802us-gaap:InterestRateContractMember2024-10-012025-09-300000731802us-gaap:FairValueInputsLevel1Member2025-09-300000731802us-gaap:FairValueInputsLevel2Member2025-09-300000731802us-gaap:FairValueInputsLevel3Member2025-09-300000731802us-gaap:EquitySecuritiesMemberus-gaap:FairValueInputsLevel1Member2025-09-300000731802us-gaap:EquitySecuritiesMemberus-gaap:FairValueInputsLevel2Member2025-09-300000731802us-gaap:EquitySecuritiesMemberus-gaap:FairValueInputsLevel3Member2025-09-300000731802us-gaap:EquitySecuritiesMember2025-09-300000731802us-gaap:FixedIncomeFundsMemberus-gaap:FairValueInputsLevel1Member2025-09-300000731802us-gaap:FixedIncomeFundsMemberus-gaap:FairValueInputsLevel2Member2025-09-300000731802us-gaap:FixedIncomeFundsMemberus-gaap:FairValueInputsLevel3Member2025-09-300000731802us-gaap:FixedIncomeFundsMember2025-09-300000731802us-gaap:DebtSecuritiesMemberus-gaap:FairValueInputsLevel1Member2025-09-300000731802us-gaap:DebtSecuritiesMemberus-gaap:FairValueInputsLevel2Member2025-09-300000731802us-gaap:DebtSecuritiesMemberus-gaap:FairValueInputsLevel3Member2025-09-300000731802us-gaap:DebtSecuritiesMember2025-09-300000731802us-gaap:MoneyMarketFundsMemberus-gaap:FairValueInputsLevel1Member2025-09-300000731802us-gaap:MoneyMarketFundsMemberus-gaap:FairValueInputsLevel2Member2025-09-300000731802us-gaap:MoneyMarketFundsMemberus-gaap:FairValueInputsLevel3Member2025-09-300000731802us-gaap:MoneyMarketFundsMember2025-09-300000731802us-gaap:FairValueInputsLevel1Member2024-09-300000731802us-gaap:FairValueInputsLevel2Member2024-09-300000731802us-gaap:FairValueInputsLevel3Member2024-09-300000731802us-gaap:EquitySecuritiesMemberus-gaap:FairValueInputsLevel1Member2024-09-300000731802us-gaap:EquitySecuritiesMemberus-gaap:FairValueInputsLevel2Member2024-09-300000731802us-gaap:EquitySecuritiesMemberus-gaap:FairValueInputsLevel3Member2024-09-300000731802us-gaap:EquitySecuritiesMember2024-09-300000731802us-gaap:FixedIncomeFundsMemberus-gaap:FairValueInputsLevel1Member2024-09-300000731802us-gaap:FixedIncomeFundsMemberus-gaap:FairValueInputsLevel2Member2024-09-300000731802us-gaap:FixedIncomeFundsMemberus-gaap:FairValueInputsLevel3Member2024-09-300000731802us-gaap:FixedIncomeFundsMember2024-09-300000731802us-gaap:DebtSecuritiesMemberus-gaap:FairValueInputsLevel1Member2024-09-300000731802us-gaap:DebtSecuritiesMemberus-gaap:FairValueInputsLevel2Member2024-09-300000731802us-gaap:DebtSecuritiesMemberus-gaap:FairValueInputsLevel3Member2024-09-300000731802us-gaap:DebtSecuritiesMember2024-09-300000731802us-gaap:MoneyMarketFundsMemberus-gaap:FairValueInputsLevel1Member2024-09-300000731802us-gaap:MoneyMarketFundsMemberus-gaap:FairValueInputsLevel2Member2024-09-300000731802us-gaap:MoneyMarketFundsMemberus-gaap:FairValueInputsLevel3Member2024-09-300000731802us-gaap:MoneyMarketFundsMember2024-09-3000007318022025-07-012025-09-30

UNITED STATES SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

Form 10-K

(Mark One)

☑ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934

For the fiscal year ended September 30, ~~2024~~2025

☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934

For the transition period from to

Commission file number 1-10042

Atmos Energy Corporation

(Exact name of registrant as specified in its charter)

Texas and Virginia 75-1743247

(State or other jurisdiction of (IRS employer

incorporation or organization) identification no.)

1800 Three Lincoln Centre

5430 LBJ Freeway

Dallas, Texas 75240

(Address of principal executive offices) (Zip code)

Registrant’s telephone number, including area code:

(972) 934-9227

Securities registered pursuant to Section 12(b) of the Act:


Table of each class		Trading Symbol	Name of each exchange on which registered
Common stock	No Par Value	ATO	New York Stock Exchange

Securities registered pursuant to Section 12(g) of the Act:

None

Indicate by check mark if the registrant is a well-known seasoned issuer, as defined in Rule 405 of the Securities Act. Yes þ No ¨

Indicate by check mark if the registrant is not required to file reports pursuant to Section 13 or Section 15(d) of the Act. Yes ¨ No þ

Indicate by check mark whether the registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days. Yes þ No ¨

Indicate by check mark whether the registrant has submitted electronically every Interactive Data File required to be submitted pursuant to Rule 405 of Regulation S-T (§ 232.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrant was required to submit such files). Yes þ No ¨

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, a smaller reporting company or an emerging growth company. See definitions of “large accelerated filer,” “accelerated filer,” “smaller reporting company” and "emerging growth company" in Rule 12b-2 of the Exchange Act. (Check one):

Large accelerated filer

☑

Accelerated filer

☐

Non-accelerated filer

☐

Smaller reporting company

☐

Emerging growth company

☐

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ¨

Indicate by check mark whether the registrant has filed a report on and attestation to its management’s assessment of the effectiveness of its internal control over financial reporting under Section 404(b) of the Sarbanes-Oxley Act (15 U.S.C. 7262(b)) by the registered public accounting firm that prepared or issued its audit report. ☑

If securities are registered pursuant to Section 12(b) of the Act, indicate by check mark whether the financial statements of the registrant included in the filing reflect the correction of an error to previously issued financial statements. ¨

Indicate by check mark whether any of those error corrections are restatements that required a recovery analysis of incentive-based compensation received by any of the registrant's executive officers during the relevant recovery period pursuant to §240.10D-1(b). ¨

Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Act). Yes ☐ No þ

The aggregate market value of the common voting stock held by non-affiliates of the registrant as of the last business day of the registrant’s most recently completed second fiscal quarter, March 31, ~~2024~~2025, was $1724,~~825~~413,~~800~~133,~~856~~216.

As of November 1410, ~~2024~~2025, the registrant had ~~155~~161,~~399~~693,~~533~~336 shares of common stock outstanding.

DOCUMENTS INCORPORATED BY REFERENCE

Portions of the registrant’s Definitive Proxy Statement to be filed for the Annual Meeting of Shareholders on February 54, ~~2025~~2026 are incorporated by reference into Part III of this report.

Table of Contents

TABLE OF CONTENTS

		Page
Glossary of Key Terms		3
	Part I
Item 1.	Business	4
Item 1A.	Risk Factors	14
Item 1B.	Unresolved Staff Comments	1918
Item 1C.	Cybersecurity	1918
Item 2.	Properties	2120
Item 3.	Legal Proceedings	22
Item 4.	Mine Safety Disclosures	22
	Part II
Item 5.	Market for Registrant’s Common Equity, Related Stockholder Matters and Issuer Purchases of Equity Securities	22
Item 6.	Reserved	24
Item 7.	Management’s Discussion and Analysis of Financial Condition and Results of Operations	24
Item 7A.	Quantitative and Qualitative Disclosures About Market Risk	3534
Item 8.	Financial Statements and Supplementary Data	36
Item 9.	Changes in and Disagreements With Accountants on Accounting and Financial Disclosure	86
Item 9A.	Controls and Procedures	86
Item 9B.	Other Information	88
Item 9C.	Disclosure Regarding Foreign Jurisdictions that Prevent Inspections	88
	Part III
Item 10.	Directors, Executive Officers and Corporate Governance	88
Item 11.	Executive Compensation	89
Item 12.	Security Ownership of Certain Beneficial Owners and Management and Related Stockholder Matters	89
Item 13.	Certain Relationships and Related Transactions, and Director Independence	89
Item 14.	Principal Accountant Fees and Services	89
	Part IV
Item 15.	Exhibits and Financial Statement Schedules	89
Item 16.	Form 10-K Summary	9495

Table of Contents

GLOSSARY OF KEY TERMS




AEK			Atmos Energy Kansas Securitization I, LLC
AFUDC			Allowance for funds used during construction
AOCI			Accumulated Other Comprehensive Income
ARM			Annual Rate Mechanism
ATO			Trading symbol for Atmos Energy Corporation common stock on the NYSE
Bcf			Billion cubic feet
COSO			Committee of Sponsoring Organizations of the Treadway Commission
DARR			Dallas Annual Rate Review
EDIT			Excess Deferred Income Taxes
ERISA			Employee Retirement Income Security Act of 1974

FERC			Federal Energy Regulatory Commission
GAAP			Generally Accepted Accounting Principles
GRIP			Gas Reliability Infrastructure Program
GSRS			Gas System Reliability Surcharge
LTIP			1998 Long-Term Incentive Plan
Mcf			Thousand cubic feet
MDWQ			Maximum daily withdrawal quantity
Mid-Tex ATM Cities			Represents a coalition of 47 incorporated cities or approximately 10 percent of the Mid-Tex Division's customers.
Mid-Tex Cities			Represents all incorporated cities other than Dallas and Mid-Tex ATM Cities, or approximately 72 percent of the Mid-Tex Division’s customers.
MMcf			Million cubic feet
Moody’s			Moody’s Investor Service, Inc.
NGPA			Natural Gas Policy Act of 1978

NYSE			New York Stock Exchange
PHMSA			Pipeline and Hazardous Materials Safety Administration
PPA			Pension Protection Act of 2006
PRP			Pipeline Replacement Program

RRC			Railroad Commission of Texas
RRM			Rate Review Mechanism
RSC			Rate Stabilization Clause
S&P			Standard & Poor’s Corporation
SAVE			Steps to Advance Virginia Energy
SEC			United States Securities and Exchange Commission
Securitized Utility Tariff Bonds			Series 2023-A Senior Secured Securitized Utility Tariff Bonds
Securitized Utility Tariff Property			As defined in the financing order issued by the KCC in October 2022
SIP			System Integrity Program
SIR			System Integrity Rider
SOFR			Secured Overnight Financing Rate
SRF			Stable Rate Filing
SSIR			System Safety and Integrity Rider
TCJA			Tax Cuts and Jobs Act of 2017
WNA			Weather Normalization Adjustment

Table of Contents

PART I

The terms “we,” “our,” “us,” “Atmos Energy,” and the “Company” refer to Atmos Energy Corporation and its subsidiaries, unless the context suggests otherwise.


ITEM 1.			Business.

Overview and Strategy

Atmos Energy Corporation, ~~headquartered~~a innatural ~~Dallas,~~gas-only ~~Texas~~distributor, ~~and~~is ~~incorporated~~an inS&P ~~Texas~~500 ~~and~~company ~~Virginia,~~headquartered isin ~~the~~Dallas ~~country’s~~and ~~largest~~incorporated ~~natural-gas-only~~in ~~distributor~~Texas ~~based~~and ~~on number of customers~~Virginia. We safely deliver reliable, efficient, and abundant natural gas through regulated sales and transportation arrangements to ~~over~~approximately 3.34 million residential, commercial, public authority, and industrial customers in eight states located primarily in the South. We also operate one of the largest intrastate pipelines in Texas based on miles of pipe.

Atmos Energy's vision is to be the safest provider of natural gas services. We will be recognized for exceptional customer service, for being a great employer, and for achieving superior financial results.

Our operating strategy is focused on modernizing our business and infrastructure while reducing regulatory lag. This operating strategy supports continued investment in safety, innovation, environmental sustainability, and our communities.

Operating Segments

We manage and review our consolidated operations through the following reportable segments:

•The distribution segment is comprised of our regulated natural gas distribution and related sales operations in eight states.

•The pipeline and storage segment is comprised primarily of the regulated pipeline and storage operations of our Atmos Pipeline-Texas division and our natural gas transmission operations in Louisiana.

Distribution Segment Overview

The following table summarizes key information about our six regulated natural gas distribution divisions, presented in order of total rate base.

Division

Service Areas

Communities Served

Customer Meters

Mid-Tex

Texas, including the Dallas/Fort Worth Metroplex

550

1,~~804~~830,~~265~~387

Kentucky/Mid-States

Kentucky

220

176,~~903~~494

Tennessee

~~161~~163,~~193~~667

Virginia

23,~~777~~836

Louisiana

270

360,~~870~~589

West Texas

Amarillo, Lubbock, Midland

~~314~~316,~~503~~036

Mississippi

110

~~251~~249,~~147~~562

Colorado-Kansas

Colorado

170

~~129~~130,~~727~~890

Kansas

~~139~~140,~~435~~542

We operate in our service areas under terms of non-exclusive franchise agreements granted by the various cities and towns that we serve. At September 30, ~~2024~~2025, we held 1,~~026~~010 franchises having terms generally ranging from five to 35 years. A number of our franchises expire each year, which require renewal prior to the end of their terms. Historically, we have successfully renewed these franchises and believe that we will continue to be able to renew our franchises as they expire.

Revenues in this operating segment are established by regulatory authorities in the states in which we operate. These rates are intended to be sufficient to cover the costs of conducting business, including a reasonable return on invested capital. In addition, we transport natural gas for others through our distribution systems.

Table of Contents

Rates established by regulatory authorities often include cost adjustment mechanisms for costs that (i) are subject to significant price fluctuations compared to our other costs, (ii) represent a large component of our cost of service, and (iii) are generally outside our control.

Purchased gas cost adjustment mechanisms represent a traditional and common form of cost adjustment mechanism. Purchased gas cost adjustment mechanisms provide a method of recovering purchased gas costs on an ongoing basis without filing a rate case because they provide a dollar-for-dollar offset to increases or decreases in the cost of natural gas. Therefore, although substantially all of our distribution operating revenues fluctuate with the cost of gas that we purchase, distribution operating income is generally not affected by fluctuations in the cost of gas.

Additionally, some jurisdictions have performance-based ratemaking adjustments to provide incentives to minimize purchased gas costs through improved storage management and use of financial instruments to reduce volatility in gas costs. Under the performance-based ratemaking adjustments, purchased gas costs savings are shared between the Company and its customers.

Our supply of natural gas is provided by a variety of suppliers, including independent producers, and marketers. The gas is delivered into our systems by various pipeline companies, withdrawals of gas from proprietary and contracted storage assets, and base load and peaking arrangements, as needed.

Supply arrangements consist of both base load and peaking quantities and are contracted from our suppliers on a firm basis with various terms at market prices. Base load quantities are those that flow at a constant level throughout the month and peaking quantities provide the flexibility to change daily quantities to match increases or decreases in requirements related to weather conditions.

Except for local production purchases, we select our natural gas suppliers through a competitive bidding process by periodically requesting proposals from suppliers. We select these suppliers based on their ability to reliably deliver gas supply to our designated firm pipeline receipt points at the lowest reasonable cost. Major suppliers during fiscal ~~2024~~2025 were ARM Energy Management LLC, Cima Energy, LP, ConocoPhillips Company, ~~EnLink~~ECO ~~Gas~~Energy ~~Marketing~~Natural ~~LP,~~Gas ~~Enterprise Navitas Midstream Midland Basin~~ LLC, ~~Hartree~~EnLink ~~Partners,~~Gas ~~L.P.~~Marketing LP, Sequent Energy Management LLC, Symmetry Energy Solutions, LLC, Targa Gas Marketing LLC, Tenaska Marking Ventures, and Texla Energy Management, Inc.

The combination of base load and peaking agreements, coupled with the withdrawal of gas held in storage, allows us the flexibility to adjust to changes in weather, which minimizes our need to enter into long-term firm commitments. We estimate our peak-day availability of natural gas supply to be approximately 5.34 Bcf. The peak-day demand for our distribution operations in fiscal ~~2024~~2025 was on ~~January~~February 1519, ~~2024~~2025, when sales to customers reached approximately 4.32 Bcf.

Currently, our distribution divisions utilize 3433 pipeline transportation companies, both interstate and intrastate, to transport our natural gas. The pipeline transportation agreements are firm and many of them have “pipeline no-notice” storage service, which provides for daily balancing between system requirements and nominated flowing supplies. These agreements have been negotiated with the shortest term necessary while still maintaining our right of first refusal. The natural gas supply for our Mid-Tex Division is delivered primarily by our APT Division.

To maintain our deliveries to high priority customers, we have the ability, and have exercised our right, to interrupt or curtail service to certain customers pursuant to contracts and applicable state regulations or statutes. Our customers’ demand on our system is not necessarily indicative of our ability to meet current or anticipated market demands or immediate delivery requirements because of factors such as the physical limitations of gathering, storage and transmission systems, the duration and severity of cold weather, the availability of gas reserves from our suppliers, the ability to purchase additional supplies on a short-term basis, and actions by federal and state regulatory authorities. Interruption and curtailment rights provide us the flexibility to meet the human-needs requirements of our customers on a reliable basis. Priority allocations imposed by federal and state regulatory agencies, as well as other factors beyond our control, may affect our ability to meet the demands of some of our customers.

Pipeline and Storage Segment Overview

Our pipeline and storage segment consists of the regulated pipeline and storage operations of APT and our natural gas transmission operations in Louisiana. APT is one of the largest intrastate pipeline operations in Texas with a heavy concentration in the established natural gas-producing areas of central, northern, and eastern Texas, extending into or near the major producing areas of the Barnett Shale, the Texas Gulf Coast, and the Permian Basin of West Texas. Through its system, APT provides transportation and storage services to our Mid-Tex Division, other third party local distribution companies, industrial and electric generation customers, marketers, and producers. As part of its pipeline operations, APT owns and operates five underground storage facilities in Texas.

Revenues earned from transportation and storage services for APT are subject to traditional ratemaking governed by the RRC. Rates are updated through periodic filings made under Texas’ GRIP. GRIP allows us to include in our rate base annually approved capital costs incurred in the prior calendar year provided that we file a complete rate case at least once every five

Table of Contents

years; the most recent of which was completed in December 2023. APT’s existing regulatory mechanisms allow certain transportation and storage services to be provided under market-based rates.

Our natural gas transmission operations in Louisiana are comprised of a 21-mile pipeline located in the New Orleans, Louisiana area that is primarily used to aggregate gas supply for our distribution division in Louisiana under a long-term contract and, on a more limited basis, to third parties. The demand fee charged to our Louisiana distribution division for these services is subject to regulatory approval by the Louisiana Public Service Commission. We also manage two asset management plans that serve distribution affiliates of the Company, which have been approved by applicable state regulatory commissions. Generally, these asset management plans require us to share with our distribution customers a significant portion of the cost savings earned from these arrangements.

Ratemaking Activity

Overview

The method of determining regulated rates varies among the states in which our regulated businesses operate. The regulatory authorities have the responsibility of ensuring that utilities in their jurisdictions operate in the best interests of customers while providing utility companies the opportunity to earn a reasonable return on their investment. Generally, each regulatory authority reviews rate requests and establishes a rate structure intended to generate revenue sufficient to cover the costs of conducting business, including a reasonable return on invested capital.

Our rate strategy focuses on reducing or eliminating regulatory lag, obtaining adequate returns, and providing stable, predictable margins, which benefit both our customers and the Company. As a result of our ratemaking efforts and legislative actions in our jurisdictions in recent years, Atmos Energy has:

•Formula rate mechanisms in place in four states that provide for an annual rate review and adjustment to rates.

•Infrastructure programs in place in all of our states that provide for an annual adjustment to rates for qualifying capital expenditures. Through our annual formula rate mechanisms and infrastructure programs, we have the ability to begin recovering approximately 9095 percent of our capital expenditures within six months and substantially all of our capital expenditures within twelve months.

•Authorization in tariffs, statute or commission rules that allows us to defer certain elements of our incurred cost of service such as depreciation, ad valorem taxes, pension costs, and certain safety related expenses, until they are included in rates.

•WNA mechanisms in seven states that serve to minimize the effects of weather on approximately 97 percent of our distribution residential and commercial revenues.

•The ability to recover the gas cost portion of bad debts in six states which represents approximately 89 percent of our distribution residential and commercial revenues.

Table of Contents

The following tables provides a jurisdictional rate summary for our regulated operations as of September 30, ~~2024~~2025. This information is for regulatory purposes only and may not be representative of our actual financial position.

Division

Jurisdiction

EffectiveDate of LastRate/GRIP Action

Rate Base(thousands)(1)

AuthorizedRate ofReturn(1)

Authorized Debt/Equity Ratio(1)

AuthorizedReturnon Equity(1)

Atmos Pipeline — Texas

Texas

0506/1417/~~2024~~2025

$45,~~773~~237,~~699~~614

8.49%

40/60

11.45%

Colorado-Kansas

Colorado

05/14/2023

229,565

7.00%

42-45/55-58

9.3% - 9.6%

Colorado SSIR

01/01/~~2024~~2025

5273,~~820~~623

7.00% / 3.97%

42/58

(4)

Kansas

05/09/2023

295,070

(4)

Kansas GSRS

1112/0217/~~2023~~2024

1638,~~546~~932

(4)

Kansas SIP

04/01/~~2024~~2025

1925,~~908~~707

(4)

Kentucky/Mid-States

Kentucky

05/2012/~~2022~~2025

~~568~~611,~~506~~038

67.8215%

4546/5554

9.2375%

Kentucky-PRP

1005/0129/~~2023~~2025

4067,~~504~~464

6.94%

45/55

9.45%

Tennessee

06/01/~~2024~~2025

~~554~~611,~~053~~649

7.6463%

3839/6261

9.80%

Virginia

12/01/2023

71,450

7.57%

39/61

9.90%

Virginia-SAVE

10/01/~~2023~~2024

1621,~~422~~436

7.4357%

4239/5861

9.2090%

Louisiana

07/01/~~2024~~2025

1,~~227~~352,~~842~~758

7.4342%

42/58

9.80%

Mid-Tex

Mid-Tex Cities(5)

10/01/~~2023~~2024

67,~~070~~146,~~321~~843(6)

7.3541%

42/58

9.80%

Mid-Tex ATM Cities

0608/0701/~~2024~~2025

7,~~009~~953,~~146~~622(6)

7.9759%

4039/6061

9.80%

Mid-Tex Environs

0608/01/~~2024~~2025

7,~~009~~953,~~154~~529(6)

7.9759%

4039/6061

9.80%

Mid-Tex — Dallas

06/01/~~2024~~2025

67,~~844~~973,~~772~~771(6)

7.4752%

40/60

9.80%

Mississippi

Mississippi(7)

1211/0104/~~2023~~2024

~~591~~592,~~882~~236

7.8280%

~~39/61~~(4)

~~10.34%~~(4)

Mississippi - SIR(7)

1211/0104/~~2023~~2024

~~472~~629,~~676~~687

7.8280%

~~39/61~~(4)

~~10.34%~~(4)

West Texas

West Texas ~~Cities~~Systemwide (8) ~~(10)~~

1006/01/~~2023~~2025

~~965~~1,~~289(9)~~231,651

7.3559%

4239/5861

9.80%

West Texas - ALDC

06/07/2024

1,062,054(9)

7.35%

41/59

(4)

West Texas - Environs

06/01/2024

1,059,604(9)

7.97%

40/60

9.80%

West Texas - Triangle

06/01/2024

65,124

7.71%

40/60

9.80%

Division

Jurisdiction

Bad Debt

Rider(2)

Formula Rate

Infrastructure Mechanism

Performance Based

Rate Program(3)

WNA Period

Atmos Pipeline — Texas

Texas

Yes

N/A

Colorado-Kansas

Colorado

Yes

N/A

Kansas

Yes

October-May

Kentucky/Mid-States

Kentucky

Yes

November-April

Tennessee

Yes

October-April

Virginia

Yes

January-December

Louisiana

Yes

December-March

Mid-Tex Cities

Texas

Yes

November-April

Mid-Tex — Dallas

Texas

Yes

November-April

Mississippi

Yes

November-April

West Texas

Texas

Yes

October-May

Table of Contents

Division

Jurisdiction

Bad DebtRider(2)

Formula Rate

Infrastructure Mechanism

Performance BasedRate Program(3)

WNA Period

Atmos Pipeline — Texas

Texas

Yes

N/A

Colorado-Kansas

Colorado

Yes

N/A

Kansas

Yes

October-May

Kentucky/Mid-States

Kentucky

Yes

November-April

Tennessee

Yes

October-April

Virginia

Yes

January-December

Louisiana

Yes

December-March

Mid-Tex Cities

Texas

Yes

November-April

Mid-Tex — Dallas

Texas

Yes

November-April

Mississippi

Yes

November-April

West Texas

Texas

Yes

October-May

(1)The rate base, authorized rate of return, authorized debt/equity ratio, and authorized return on equity presented in this table are those from the most recent approved regulatory filing for each jurisdiction. These rate bases, rates of return, debt/equity ratios, and returns on equity are not necessarily indicative of current or future rate bases, rates of return or returns on equity.

(2)The bad debt rider allows us to recover from customers the gas cost portion of customer accounts that have been written off.

Table of Contents

(3)The performance-based rate program provides incentives to distribution companies to minimize purchased gas costs by allowing the companies and their customers to share the purchased gas costs savings.

(4)A rate base, rate of return, return on equity, or debt/equity ratio was not included in the respective state commission’s final decision.

(5)The Mid-Tex Cities approved the Formula Rate Mechanism filing with rates effective October 1, ~~2024~~2025, which included a rate base of $78.13 billion, an authorized return of 7.4142%, a debt/equity ratio of 42/58, and an authorized ROE of 9.80%.

(6)The Mid-Tex rate base represents a “system-wide,” or 100 percent, of the Mid-Tex Division’s rate base.

(7)The Mississippi SRF and SIR were filed jointly in a general rate case. On November 4, 2025, the Mississippi Public Service Commission ~~approved~~issued a ~~settlement~~rate atorder ~~its~~in ~~meeting~~this oncase. We are required to file tariffs consistent with the final order by November 418, ~~2024~~2025, which ~~included~~we aexpect will determine the final impact to operating income and rate base. We expect rates to be implemented during the first quarter of $1fiscal 2026.2 ~~billion~~The ~~and~~final order included an authorized return of 76.80%~~. No~~, a debt/equity ratio orof 50/50, and an authorized ROE ~~was~~of ~~included in the commissions final order~~9.40%.

(8)The West Texas ~~Cities~~Systemwide ~~includes~~Statement ~~all~~of Intent filing included the West Texas ~~Division~~RRM ~~cities~~and ~~except~~the Amarillo, Lubbock, Dalhart and Channing (ALDC), Environs, and Triangle GRIP filings.

(9)The West Texas rate base represents a "system-wide," or 100 percent, of the West Texas Division's rate base.

(10)The West Texas Cities approved the Formula Rate Mechanism filing with rates effective October 1, 2024, which included a rate base of $1.1 billion, an authorized return of 7.41%, a debt/equity ratio of 42/58 and an authorized ROE of 9.80%.

Although substantial progress has been made in recent years to improve rate design and recovery of investment across our service areas, we are continuing to seek improvements in rate design to address cost variations and pursue tariffs that reduce regulatory lag associated with investments. Further, potential changes in federal energy policy, federal safety regulations, and changing economic conditions will necessitate continued vigilance by the Company and our regulators in meeting the challenges presented by these external factors.

Recent Ratemaking Activity

The amounts described in the following sections represent the annual operating income that was requested or received in each rate filing, which may not necessarily reflect the stated amount referenced in the final order, as certain operating costs may have changed as a result of the commission's or other governmental authority's final ruling. Our ratemaking outcomes include the refund (return) of excess deferred income taxes (EDIT) resulting from previously enacted tax reform legislation and do not reflect the true economic benefit of the outcomes because they do not include the corresponding income tax benefit. The following tables summarize the annualized ratemaking outcomes we implemented in each of the last three fiscal years.


Rate Action	Annual Increase (Decrease) in Operating Income		EDIT Impact		Annual Increase (Decrease) in Operating Income Excluding EDIT
	(In thousands)
2025 Filings:
Annual formula rate mechanisms	$	279,724	$	2,255	$	281,979
Rate case filings	53,732		(12,976)		40,756
Other ratemaking activity	111		—		111
Total 2025 Filings	$	333,567	$	(10,721)	$	322,846

2024 Filings:
Annual formula rate mechanisms	$	347,763	$	(31,314)	$	316,449
Rate case filings	29,458		(37,860)		(8,402)
Other ratemaking activity	(971)		—		(971)
Total 2024 Filings	$	376,250	$	(69,174)	$	307,076

2023 Filings:
Annual formula rate mechanisms	$	258,824	$	(1,099)	$	257,725
Rate case filings	2,940		6,791		9,731
Other ratemaking activity	1,320		—		1,320
Total 2023 Filings	$	263,084	$	5,692	$	268,776

The following ratemaking efforts seeking $231.1 million in annual operating income were initiated during fiscal 2025 but had not been completed or implemented as of September 30, 2025:

Table of Contents

Rate Action	Annual Increase (Decrease) in Operating Income		EDIT Impact		Annual Increase (Decrease) in Operating Income Excluding EDIT
Division	Rate Action		Jurisdiction		Operating IncomeRequested
	~~(In thousands)~~				(In thousands)
2024 Filings:
Colorado-Kansas	Rate Case		Kansas		$	15,977
Annual formula rate mechanisms	$	347,763	$	(31,314)	$	316,449
Colorado-Kansas	Infrastructure Mechanism		Kansas (1)		1,949
Rate case filings	29,458		(37,860)		(8,402)
Kentucky/Mid-States	Infrastructure Mechanism		Virginia (2)		550
Other ratemaking activity	(971)		—		(971)
Kentucky/Mid-States	Infrastructure Mechanism		Kentucky (3)		7,246
Total 2024 Filings	$	376,250	$	(69,174)	$	307,076
Mid-Tex	Formula Rate Mechanism		Mid-Tex Cities (4)		165,027
2023 Filings:
Mississippi	Rate Case		Mississippi (5)		40,301
Annual formula rate mechanisms	$	258,824	$	(1,099)	$	257,725
					$	231,050
Rate case filings	2,940		6,791		9,731
Other ratemaking activity	1,320		—		1,320
Total 2023 Filings	$	263,084	$	5,692	$	268,776
2022 Filings:
Annual formula rate mechanisms	$	169,354	$	33,249	$	202,603
Rate case filings	5,938		7,379		13,317
Other ratemaking activity	(370)		—		(370)
Total 2022 Filings	$	174,922	$	40,628	$	215,550

(1) The ~~following~~staff ~~ratemaking~~of ~~efforts~~the ~~seeking~~Kansas ~~$218.0~~Corporation ~~million~~Commission inrecommended ~~annual~~approval ~~operating~~of ~~income~~the ~~were~~GSRS ~~initiated~~filing ~~during~~on ~~fiscal~~October ~~2024~~17, ~~but~~2025, ~~had~~subject ~~not~~to ~~been~~commission ~~completed or implemented as of September 30, 2024:~~approval.

Division

Rate Action

Jurisdiction

Operating IncomeRequested

(In thousands)

Colorado-Kansas

Infrastructure Mechanism

Kansas (1)

1,998

Kentucky/Mid-States

Infrastructure Mechanism

Virginia (2)

748

Kentucky/Mid-States

Infrastructure Mechanism

Kentucky (3)

3,441

Kentucky/Mid-States

Rate Case

Kentucky

33,654

Mid-Tex

Formula Rate Mechanism

Mid-Tex Cities (4)

133,414

Mississippi

Infrastructure Mechanism

Mississippi (5)

21,830

Mississippi

Formula Rate Mechanism

Mississippi (5)

16,244

West Texas

Formula Rate Mechanism

West Texas Cities (6)

6,709

218,038

(2) On August 22, 2025, the State Corporation Commission of Virginia approved a rate increase of $0.5 million effective October 1, 2025.

(13) ~~The~~ On ~~staff~~September of15, 2025, the ~~Kansas~~Kentucky ~~Corporation~~Public Service Commission ~~recommended~~approved ~~approval~~a ofrate ~~the~~increase ~~GSRS~~of ~~filing~~$7.2 onmillion effective October 172, ~~2024~~2025, subject to ~~commission approval~~refund.

(24) OnThe ~~September~~Mid-Tex 4,Cities ~~2024, the State Corporation Commission of Virginia~~ approved a rate increase of $0138.75 million. ~~effective~~New rates were implemented October 1, ~~2024~~2025.

(35) On ~~September~~November 274, ~~2024~~2025, the ~~Kentucky~~Mississippi Public Service Commission ~~approved~~issued a rate ~~increase~~order ofin $3this case.4 ~~million~~We ~~effective~~are ~~October~~required 2to file tariffs consistent with the final order by November 18, ~~2024~~2025, ~~subject~~which we expect will determine the final impact to ~~refund~~operating income and rate base. We expect rates to be implemented during the first quarter of fiscal 2026.

(4) The Mid-Tex Cities approved a rate increase of $112.1 million. New rates were implemented October 1, 2024.

(5) On November 4, 2024, the Mississippi Public Service Commission (MPSC) approved an increase in operating income of $24.0 million for the SIR filing and an increase in operating income of $3.8 million for the SRF filing.

(6) The West Texas Cities approved a rate increase of $4.4 million. New rates were implemented on October 1, 2024.

Our recent ratemaking activity is discussed in greater detail below.

Annual Formula Rate Mechanisms

As an instrument to reduce regulatory lag, formula rate mechanisms allow us to refresh our rates on an annual basis without filing a formal rate case. However, these filings still involve discovery by the appropriate regulatory authorities prior to the final determination of rates under these mechanisms. We currently have specific infrastructure programs in all of our distribution divisions with tariffs in place to permit the investment associated with these programs to have their surcharge rate adjusted annually to recover approved capital costs incurred in a prior test-year period. The following table summarizes our annual formula rate mechanisms by state.

Annual Formula Rate Mechanisms

State

Infrastructure Programs

Formula Rate Mechanisms

Colorado

System Safety and Integrity Rider (SSIR)

—

Kansas

Gas System Reliability Surcharge (GSRS), System Integrity Program (SIP)

—

Kentucky

Pipeline Replacement Program (PRP)

—

Louisiana

(1)

Rate Stabilization Clause (RSC)

Mississippi

System Integrity Rider (SIR)

Stable Rate Filing (SRF)

Tennessee

(1)

Annual Rate Mechanism (ARM)

Texas

Gas Reliability Infrastructure Program (GRIP), (1)

Dallas Annual Rate Review (DARR), Mid-Tex Rate Review Mechanism (RRM)

Virginia

Steps to Advance Virginia Energy (SAVE)

—

(1) Infrastructure mechanisms in Texas, Louisiana, and Tennessee allow for the deferral of all expenses associated with capital expenditures incurred pursuant to these rules, which primarily consists of interest, depreciation, and other taxes (Texas and Tennessee only), until the next rate proceeding (rate case or annual rate filing), at which time investment and costs would be recoverable through base rates.

Table of Contents

Annual Formula Rate Mechanisms

State

Infrastructure Programs

Formula Rate Mechanisms

Colorado

System Safety and Integrity Rider (SSIR)

—

Kansas

Gas System Reliability Surcharge (GSRS), System Integrity Program (SIP)

—

Kentucky

Pipeline Replacement Program (PRP)

—

Louisiana

(1)

Rate Stabilization Clause (RSC)

Mississippi

System Integrity Rider (SIR)

Stable Rate Filing (SRF)

Tennessee

(1)

Annual Rate Mechanism (ARM)

Texas

Gas Reliability Infrastructure Program (GRIP), (1)

Dallas Annual Rate Review (DARR), Rate Review Mechanism (RRM)

Virginia

Steps to Advance Virginia Energy (SAVE)

—

The following table summarizes our annual formula rate mechanisms with effective dates during the fiscal years ended September 30, 2025, 2024, and 2023:

(1) Infrastructure mechanisms in Texas, Louisiana, and Tennessee allow for the deferral of all expenses associated with capital expenditures incurred pursuant to these rules, which primarily consists of interest, depreciation, and other taxes (Texas only), until the next rate proceeding (rate case or annual rate filing), at which time investment and costs would be recoverable through base rates.


Division	Jurisdiction	Test Year Ended	Increase in Annual Operating Income		EDIT Impact		Increase (Decrease) in Annual Operating Income Excluding EDIT		Effective Date
					(In thousands)
2025 Filings:

Louisiana	Louisiana	12/2024	$	22,304	$	1,473	$	23,777	07/01/2025











Atmos Pipeline - Texas	Texas	12/2024	77,206		—		77,206		06/17/2025
Kentucky/Mid-States	Tennessee ARM	09/2024	1,432		—		1,432		06/01/2025
Mid-Tex	DARR	09/2024	25,916		—		25,916		06/01/2025
Kentucky/Mid-States	Kentucky PRP (1)	09/2025	3,248		—		3,248		05/29/2025
Colorado-Kansas	Kansas SIP	12/2024	612		—		612		04/01/2025
Colorado-Kansas	Colorado SSIR	12/2025	1,907		—		1,907		01/01/2025
Colorado-Kansas	Kansas GSRS	09/2024	1,998		—		1,998		12/17/2024


Mississippi	Mississippi - SIR	10/2025	23,995		—		23,995		11/04/2024
Mississippi	Mississippi - SRF	10/2025	3,800		15		3,815		11/04/2024


Mid-Tex	Mid-Tex Cities RRM	12/2023	112,144		645		112,789		10/01/2024
West Texas	West Texas Cities RRM	12/2023	4,414		122		4,536		10/01/2024
Kentucky/Mid-States	Virginia - SAVE	09/2025	748		—		748		10/01/2024
Total 2025 Filings			$	279,724	$	2,255	$	281,979

2024 Filings:

Louisiana	Louisiana	12/2023	$	35,645	$	(11,785)	$	23,860	07/01/2024

Mid-Tex	ATM Cities	12/2023	17,104		—		17,104		06/07/2024
West Texas	Amarillo, Lubbock, Dalhart and Channing	12/2023	7,344		—		7,344		06/07/2024
Kentucky/Mid-States	Tennessee ARM	09/2023	18,570		(4,348)		14,222		06/01/2024
Mid-Tex	DARR	09/2023	37,809		(14,782)		23,027		06/01/2024
West Texas	Triangle	12/2023	1,300		—		1,300		06/01/2024
West Texas	Environs	12/2023	1,379		—		1,379		06/01/2024

Mid-Tex	Environs	12/2023	8,529		—		8,529		06/01/2024


Atmos Pipeline - Texas	Texas	12/2023	82,440		—		82,440		05/14/2024
Colorado-Kansas	Kansas SIP	12/2023	708		—		708		04/01/2024

Colorado-Kansas	Colorado SSIR	12/2024	2,017		—		2,017		01/01/2024


Mississippi	Mississippi - SIR	10/2024	10,969		—		10,969		12/01/2023
Mississippi	Mississippi - SRF	10/2024	11,539		(472)		11,067		12/01/2023
Colorado-Kansas	Kansas GSRS	09/2023	1,752		—		1,752		11/02/2023
Kentucky/Mid-States	Kentucky PRP	09/2024	2,906		—		2,906		10/01/2023
Mid-Tex	Mid-Tex Cities RRM	12/2022	98,585		185		98,770		10/01/2023
West Texas	West Texas Cities RRM	12/2022	8,594		(112)		8,482		10/01/2023
Kentucky/Mid-States	Virginia - SAVE	09/2024	573		—		573		10/01/2023

Total 2024 Filings			$	347,763	$	(31,314)	$	316,449

The following table summarizes our annual formula rate mechanisms with effective dates during the fiscal years ended September 30, 2024, 2023, and 2022:

Division	Jurisdiction	Test YearEnded	Increase(Decrease) inAnnualOperatingIncome		EDIT Impact		Increase (Decrease) in Annual Operating Income Excluding EDIT		EffectiveDate
					(In thousands)
2024 Filings:
Louisiana	Louisiana	12/2023	$	35,645	$	(11,785)	$	23,860	07/01/2024
Mid-Tex	ATM Cities	12/2023	17,104		—		17,104		06/07/2024
West Texas	Amarillo, Lubbock, Dalhart and Channing	12/2023	7,344		—		7,344		06/07/2024
Kentucky/Mid-States	Tennessee ARM	09/2023	18,570		(4,348)		14,222		06/01/2024
Mid-Tex	DARR	09/2023	37,809		(14,782)		23,027		06/01/2024
West Texas	Triangle	12/2023	1,300		—		1,300		06/01/2024
West Texas	Environs	12/2023	1,379		—		1,379		06/01/2024
Mid-Tex	Environs	12/2023	8,529		—		8,529		06/01/2024
Atmos Pipeline - Texas	Texas	12/2023	82,440		—		82,440		05/14/2024
Colorado-Kansas	Kansas SIP	12/2023	708		—		708		04/01/2024
Colorado-Kansas	Colorado SSIR	12/2024	2,017		—		2,017		01/01/2024
Mississippi	Mississippi - SIR	10/2024	10,969		—		10,969		12/01/2023
Mississippi	Mississippi - SRF	10/2024	11,539		(472)		11,067		12/01/2023
Colorado-Kansas	Kansas GSRS	09/2023	1,752		—		1,752		11/02/2023
Kentucky/Mid-States	Kentucky PRP	09/2024	2,906		—		2,906		10/01/2023
Mid-Tex	Mid-Tex Cities RRM	12/2022	98,585		185		98,770		10/01/2023
West Texas	West Texas Cities RRM	12/2022	8,594		(112)		8,482		10/01/2023
Kentucky/Mid-States	Virginia - SAVE	09/2024	573		—		573		10/01/2023
Total 2024 Filings			$	347,763	$	(31,314)	$	316,449

Table of Contents

2023 Filings:
Louisiana	Louisiana	12/2022	$	14,466	$	17	$	14,483	07/01/2023
Mid-Tex	DARR (12)	09/2022	17,345		51		17,396		06/14/2023
Mid-Tex	ATM Cities	12/2022	12,825		—		12,825		06/09/2023
West Texas	Amarillo, Lubbock, Dalhart and Channing	12/~~2022~~2023	6,938		—		6,938		06/09/2023
West Texas	Triangle	12/2022	717		—		717		06/01/2023
West Texas	Environs	12/2022	1,332		—		1,332		06/01/2023
Mid-Tex	Environs	12/2022	5,983		—		5,983		06/01/2023
Kentucky/Mid-States	Tennessee ARM	09/2022	14		(1,509)		(1,495)		06/01/2023
Atmos Pipeline - Texas	Texas	12/2022	84,931		—		84,931		05/17/2023
Colorado-Kansas	Kansas SIP	12/2022	772		—		772		04/01/2023
Colorado-Kansas	Colorado SSIR	12/2023	1,971		—		1,971		01/01/2023
Mississippi	Mississippi - SIR	10/2023	8,560		—		8,560		11/01/2022
Mississippi	Mississippi - SRF	10/2023	12,188		778		12,966		11/01/2022
Kentucky/Mid-States	Kentucky PRP	09/2023	1,588		—		1,588		10/02/2022
Mid-Tex	Mid-Tex Cities RRM	12/2021	81,402		(395)		81,007		10/01/2022
West Texas	West Texas Cities RRM	12/2021	7,315		(41)		7,274		10/01/2022
Kentucky/Mid-States	Virginia - SAVE	09/2023	477		—		477		10/01/2022
Total 2023 Filings			$	258,824	$	(1,099)	$	257,725
2022 Filings:
Kentucky/Mid-States	Tennessee ARM	09/2021	$	2,466	$	—	$	2,466	07/01/2022
Louisiana	Louisiana	12/2021	17,650		(10,389)		7,261		07/01/2022
West Texas	Amarillo, Lubbock, Dalhart and Channing	12/2021	6,122		—		6,122		06/11/2022
West Texas	Triangle	12/2021	1,549		—		1,549		06/11/2022
West Texas	Environs	12/2021	1,221		—		1,221		06/11/2022
Mid-Tex	ATM Cities	12/2021	12,815		—		12,815		06/10/2022
Mid-Tex	Environs	12/2021	5,646		—		5,646		06/10/2022
Mid-Tex	DARR (2)	09/2021	13,201		—		13,201		05/25/2022
Atmos Pipeline - Texas	Texas	12/2021	78,750		—		78,750		05/18/2022
Colorado-Kansas	Kansas SIP	12/2021	623		—		623		04/01/2022
Colorado-Kansas	Kansas GSRS	09/2021	1,820		—		1,820		02/01/2022
Colorado-Kansas	Colorado SSIR	12/2022	2,610		—		2,610		01/01/2022
Mid-Tex	Mid-Tex Cities RRM	12/2020	21,673		33,851		55,524		12/01/2021
West Texas	West Texas Cities RRM	12/2020	151		3,347		3,498		12/01/2021
Mississippi	Mississippi - SIR	10/2022	8,354		2,123		10,477		11/01/2021
Mississippi	Mississippi - SRF	10/2022	(5,624)		4,317		(1,307)		11/01/2021
Kentucky/Mid-States	Virginia - SAVE	09/2022	327		—		327		10/01/2021
Total 2022 Filings			$	169,354	$	33,249	$	202,603

(1) ~~The~~On ~~rate~~October ~~increase~~2, ~~for~~2024, ~~this~~we ~~filing~~implemented ~~was~~the ~~approved~~PRP ~~based~~rates onsubject ~~the~~to ~~effective~~refund; ~~date~~on ~~herein;~~May ~~however~~29, 2025, the ~~new~~Kentucky ~~rates~~Public ~~were~~Service ~~implemented~~Commission ~~beginning~~issued ~~September~~a 1,final ~~2023~~order approving the PRP filing.

(2) The rate increase for this filing was approved based on the effective date herein; however, the new rates were implemented beginning September 1, ~~2022~~2023.

Table of Contents

Rate Case Filings

A rate case is a formal request from Atmos Energy to a regulatory authority to increase rates that are charged to customers. Rate cases may also be initiated when the regulatory authorities request us to justify our rates. This process is referred to as a “show cause” action. Adequate rates are intended to provide for recovery of the Company’s costs as well as a reasonable rate of return to our shareholders and ensure that we continue to safely deliver reliable, reasonably priced natural gas service to our customers.

The following table summarizes our recent rate case activity during the fiscal years ended September 30, ~~2024~~2025, ~~2023~~2024, and ~~2022~~2023:

Division	State	Increase in Annual Operating Income		EDIT Impact		Increase (Decrease) in Annual Operating Income Excluding EDIT		Effective Date
				(In thousands)
2024 Rate Case Filings:
Atmos Pipeline - Texas	Texas	$	27,024	$	(36,921)	$	(9,897)	12/13/2023
Kentucky/Mid-States	Virginia	2,434		(939)		1,495		12/01/2023
Total 2024 Rate Case Filings		$	29,458	$	(37,860)	$	(8,402)
2023 Rate Case Filings:
Colorado-Kansas	Colorado	$	913	$	(54)	$	859	05/14/2023
Colorado-Kansas	Kansas	2,027		6,845		8,872		05/09/2023
Total 2023 Rate Case Filings		$	2,940	$	6,791	$	9,731
2022 Rate Case Filings:
Kentucky/Mid-States	Kentucky (1)	$	5,938	$	7,379	$	13,317	05/20/2022
Total 2022 Rate Case Filings		$	5,938	$	7,379	$	13,317

(1) The rate case outcome for Kentucky is inclusive of the fiscal 2022 pipeline replacement program.

Other Ratemaking Activity

The following table summarizes other ratemaking activity during the fiscal years ended September 30, 2024, 2023, and 2022:

Division

Jurisdiction

Rate Activity

Increase (Decrease) in AnnualOperating Income

EffectiveDate

(In thousands)

2024 Other Rate Activity:

Colorado-Kansas

Kansas

Ad Valorem (1)

(971)

02/01/2024

Total 2024 Other Rate Activity

(971)

2023 Other Rate Activity:

Colorado-Kansas

Kansas

Ad Valorem (1)

1,320

02/01/2023

Total 2023 Other Rate Activity

1,320

2022 Other Rate Activity:

Colorado-Kansas

Kansas

Ad-Valorem (1)

(370)

02/01/2022

Total 2022 Other Rate Activity

(370)

(1)The Ad Valorem filing relates to property taxes that are either over or undercollected compared to the amount included in our Kansas service area's base rates.

Other Regulation

Table of Contents

There are no administrative or judicial proceedings arising under environmental quality statutes pending or known to be contemplated by governmental agencies which would have a material adverse effect on us or our operations. The Pipeline and Hazardous Materials Safety Administration (PHMSA), within the U.S. Department of Transportation, develops and enforces regulations for the safe, reliable, and environmentally sound operation of the pipeline transportation system. The PHMSA pipeline safety statutes provide for states to assume safety authority over intrastate natural transmission and distribution gas pipelines. State pipeline safety programs are responsible for adopting and enforcing the federal and state pipeline safety regulations for intrastate natural gas transmission and distribution pipelines.


Division	State	Increase in Annual Operating Income		EDIT Impact		Increase (Decrease) in Annual Operating Income Excluding EDIT		Effective Date
				(In thousands)
2025 Rate Case Filings:
Mid-Tex ATM Cities	Texas	$	4,439	$	25	$	4,464	08/01/2025
Mid-Tex Environs	Texas	2,297		(174)		2,123		08/01/2025
West Texas Systemwide	Texas	30,615		(4,343)		26,272		06/01/2025
Kentucky/Mid-States	Kentucky (1)	16,381		(8,484)		7,897		05/12/2025
Total 2025 Rate Case Filings		$	53,732	$	(12,976)	$	40,756
2024 Rate Case Filings:
Atmos Pipeline - Texas	Texas	$	27,024	$	(36,921)	$	(9,897)	12/13/2023
Kentucky/Mid-States	Virginia	2,434		(939)		1,495		12/01/2023
Total 2024 Rate Case Filings		$	29,458	$	(37,860)	$	(8,402)
2023 Rate Case Filings:
Colorado-Kansas	Colorado	$	913	$	(54)	$	859	05/14/2023
Colorado-Kansas	Kansas	2,027		6,845		8,872		05/09/2023
Total 2023 Rate Case Filings		$	2,940	$	6,791	$	9,731

(1) On May 12, 2025, we implemented rates subject to refund; on August 11, 2025, the Kentucky Public Service Commission issued a final order.

Other Regulation

We are regulated by various state or local public utility authorities. We are also subject to regulation by the United States Department of Transportation with respect to safety requirements in the operation and maintenance of our transmission and distribution facilities. In addition, our operations are also subject to various state and federal laws regulating environmental matters. From time to time, we receive inquiries regarding various environmental matters. We believe that our properties and operations comply with, and are operated in conformity with, applicable safety and environmental statutes and regulations. There are no administrative or judicial proceedings arising under environmental quality statutes pending or known to be contemplated by governmental agencies which would have a material adverse effect on us or our operations. The Pipeline and Hazardous Materials Safety Administration (PHMSA), within the U.S. Department of Transportation, develops and enforces regulations for the safe, reliable, and environmentally sound operation of the pipeline transportation system. The PHMSA pipeline safety statutes provide for states to assume safety authority over intrastate natural transmission and distribution gas pipelines. State pipeline safety programs are responsible for adopting and enforcing the federal and state pipeline safety regulations for intrastate natural gas transmission and distribution pipelines.

The Federal Energy Regulatory Commission (FERC) allows, pursuant to Section 311 of the Natural Gas Policy Act (NGPA), gas transportation services through our APT assets “on behalf of” interstate pipelines or local distribution companies served by interstate pipelines, without subjecting these assets to the jurisdiction of the FERC under the NGPA. Additionally, the FERC has regulatory authority over the use and release of interstate pipeline and storage capacity. The FERC also has authority to detect and prevent market manipulation and to enforce compliance with FERC’s other rules, policies, and orders by companies engaged in the sale, purchase, transportation, or storage of natural gas in interstate commerce. We have taken what we believe are the necessary and appropriate steps to comply with these regulations.

The SEC and the Commodities Futures Trading Commission, pursuant to the Dodd–Frank Act, established numerous regulations relating to U.S. financial markets. We enacted procedures and modified existing business practices and contractual arrangements to comply with such regulations.

Competition

Although our regulated distribution operations are not currently in significant direct competition with any other distributors of natural gas to residential and commercial customers within our service areas, we do compete with other natural gas suppliers and suppliers of alternative fuels for sales to industrial customers. We compete in all aspects of our business with alternative energy sources, including, in particular, electricity. Electric utilities offer electricity as a rival energy source and compete for the space heating, water heating, and cooking markets. Promotional incentives, improved equipment efficiencies, and promotional rates all contribute to the acceptability of electrical equipment. The principal means to compete against ~~alternative fuels is lower prices, and natural gas historically has maintained its price advantage in the residential, commercial, and industrial markets.~~

Table of Contents

alternative fuels is lower prices, and natural gas historically has maintained its price advantage in the residential, commercial, and industrial markets.

Our pipeline and storage operations have historically faced competition from other existing intrastate pipelines seeking to provide or arrange transportation, storage, and other services for customers. In the last few years, several new pipelines have been completed, which has increased the level of competition in this segment of our business.

Employees

The Corporate Responsibility, Sustainability, and Safety Committee of the Board of Directors oversees matters relating to equal employment opportunities, diversity, and inclusion; human workplace rights; employee health and safety; and the Company’s vision, values, and culture. It oversees the Company's policies, practices, and procedures relating to sustainability to support the alignment of the Company's sustainability strategy with the Company's corporate strategy.

Part of our vision is to create a culture that respects and appreciates diversity. For this reason, we strive to have a workforce that reflects the communities we serve. At September 30, ~~2024~~2025, we had 5,~~260~~487 employees. We monitor our workforce data on a calendar year basis. As of December 31, ~~2023~~2024, the last date for which information is available, 6162 percent of our employees worked in field roles and 3938 percent worked in support/shared services roles. None of our employees have chosen to work under a collective bargaining agreement.

To recruit and hire individuals with a variety of skills, talents, backgrounds, and experiences, we value and cultivate our strong relationships with various community and diversity outreach sources. We also target jobs fairs including those focused on minority, veteran, and women candidates and partner with local colleges and universities to identify and recruit qualified applicants in each of the cities and towns we serve. Finally, we believe we offer a competitive benefits program to help retain our employees.

Table of Contents

applicants in each of the cities and towns we serve. Finally, we believe we offer a competitive benefits program to help retain our employees.

We perform succession planning annually to ensure that we develop and sustain a strong bench of talent capable of performing at the highest levels. Not only is talent identified, but potential paths of development are discussed to ensure that employees have an opportunity to build their skills and are well-prepared for future roles. The strength of our succession planning process is evident through our long history of promoting most of our leaders from within the organization.

Available Information

Our Annual Reports on Form 10-K, Quarterly Reports on Form 10-Q, Current Reports on Form 8-K, and other reports, and amendments to those reports, and other forms that we file with or furnish to the Securities and Exchange Commission (SEC) at their website, www.sec.gov, are also available free of charge at our website, www.investors.atmosenergy.com/~~company~~financials/~~publications-and-~~sec-filings/default.aspx, as soon as reasonably practicable, after we electronically file these reports with, or furnish these reports to, the SEC. We will also provide copies of these reports free of charge upon request to ~~Shareholder~~Investor Relations at the address and telephone number appearing below:

~~Shareholder Relations~~13

Table of Contents

Investor Relations

Atmos Energy Corporation

P.O. Box 650205

Dallas, Texas 75265-0205

972-855-3729

Corporate Governance

In accordance with and pursuant to relevant related rules and regulations of the SEC as well as corporate governance-related listing standards of the New York Stock Exchange (NYSE), the Board of Directors of the Company has established and periodically updated our Corporate Governance Guidelines and Code of Conduct, which is applicable to all directors, officers, and employees of the Company. In addition, in accordance with and pursuant to such NYSE listing standards, our Chief Executive Officer during fiscal ~~2024~~2025, John K. Akers, certified to the New York Stock Exchange that he was not aware of any violations by the Company of NYSE corporate governance listing standards. The Board of Directors also annually reviews and updates, if necessary, the charters for each of its Audit, Human Resources, Nominating and Corporate Governance, and Corporate Responsibility, Sustainability, and Safety Committees. All of the foregoing documents are posted on our website at www.atmosenergy.com/company/corporate-responsiblity-reports. We will also provide copies of all corporate governance documents free of charge upon request to ~~Shareholder~~Investor Relations at the address listed above.


ITEM 1A.			Risk Factors.

Our financial and operating results are subject to a number of risk factors, many of which are not within our control. Investors should carefully consider the following discussion of risk factors as well as other information appearing in this report. These factors include the following, which are organized by category:

Regulatory and Legislative Risks

We are subject to federal, state, and local regulations that affect our operations and financial results.

We are subject to safety and financial regulatory oversight from various federal, state, and local regulatory authorities in the eight states that we serve. Therefore, our returns are continuously monitored and are subject to challenge for their reasonableness by the appropriate regulatory authorities or other third-party intervenors. In the normal course of business, as a regulated entity, we often need to place assets in service and establish historical test periods before rate cases that seek to adjust our allowed returns to recover that investment can be filed. Further, the regulatory review process can be lengthy in the context of traditional ratemaking. Because of this process, we could suffer the negative financial effects of having placed assets in service without the benefit of rate relief, which is commonly referred to as “regulatory lag.”

Table of Contents

our allowed returns to recover that investment can be filed. Further, the regulatory review process can be lengthy in the context of traditional ratemaking. Because of this process, we could suffer the negative financial effects of having placed assets in service without the benefit of rate relief, which is commonly referred to as “regulatory lag.”

Regulatory authorities in the states we serve have approved various infrastructure and annual rate adjustment mechanisms to effectively reduce the regulatory lag inherent in the ratemaking process. Regulatory lag could significantly increase if the regulatory authorities modify or terminate these rate mechanisms. The regulatory process also involves the risk that regulatory authorities may (i) review our purchases of natural gas and adjust the amount of our gas costs that we pass through to our customers or (ii) limit or disallow the costs we may have incurred from our cost of service that can be recovered from customers.

We are also subject to laws, regulations, and other legal requirements enacted or adopted by federal, state, and local governmental authorities relating to protection of the environment and health and safety matters, including those that govern discharges of substances into the air and water, the management and disposal of hazardous substances and waste, the clean-up of contaminated sites, groundwater quality and availability, plant and wildlife protection, as well as work practices related to employee health and safety. Environmental legislation also requires that our facilities, sites, and other properties associated with our operations be operated, maintained, abandoned, and reclaimed to the satisfaction of applicable regulatory authorities. Failure to comply with these laws, regulations, permits, and licenses may expose us to fines, penalties, or interruptions in our operations that could be significant to our financial results. In addition, existing environmental regulations may be revised or our operations may become subject to new regulations.

Some of our operations are subject to increased federal regulatory oversight that could affect our operations and financial results.

FERC has regulatory authority over some of our operations, including the use and release of interstate pipeline and storage capacity. FERC has adopted rules designed to prevent market power abuse and market manipulation and to promote compliance with FERC’s other rules, policies, and orders by companies engaged in the sale, purchase, transportation, or storage of natural gas in interstate commerce. These rules carry increased penalties for violations. Although we have taken steps to structure current and future transactions to comply with applicable current FERC regulations, changes in FERC regulations or their ~~interpretation by FERC or additional regulations issued by FERC in the future could also adversely affect our business, financial condition, or financial results.~~

Table of Contents

interpretation by FERC or additional regulations issued by FERC in the future could also adversely affect our business, financial condition, or financial results.

We may experience increased federal, state, and local regulation of the safety of our operations.

The safety and protection of the public, our customers, and our employees is our top priority. We constantly monitor and maintain our pipeline and distribution systems to ensure that natural gas is delivered safely, reliably, and efficiently through our network of more than 8081,000 miles of distribution and transmission lines. As in recent years, natural gas distribution and pipeline companies are continuing to encounter increasing federal, state, and local oversight of the safety of their operations. Although we believe these are costs ultimately recoverable through our rates, the costs of complying with new laws and regulations may have at least a short-term adverse impact on our operating costs and financial results.

Operational Risks

We may incur significant costs and liabilities resulting from pipeline integrity and other similar programs and related repairs.

PHMSA requires pipeline operators to develop integrity management programs to comprehensively evaluate certain areas along their pipelines and to take additional measures to protect pipeline segments located in “high consequence areas” where a leak or rupture could potentially do the most harm. As a pipeline operator, the Company is required to:

•perform ongoing assessments of pipeline integrity;

•identify and characterize applicable threats to pipeline segments that could impact a “high consequence area”;

•improve data collection, integration, and analysis;

•repair and remediate the pipeline as necessary; and

•implement preventative and mitigating actions.

The Company incurs significant costs to comply with existing PHMSA and comparable state regulations. Although we believe these costs are ultimately recoverable through our rates, the costs of complying with new laws and regulations may have at least a short-term adverse impact on our operating costs and financial results. For example, the adoption of new regulations requiring more comprehensive or stringent safety standards could require installation of new or modified safety controls, new capital projects, or accelerated maintenance programs, all of which could require a potentially significant increase in operating costs.

Table of Contents

Distributing, transporting, and storing natural gas involve risks that may result in accidents and additional operating costs.

Our operations involve a number of hazards and operating risks inherent in storing and transporting natural gas that could affect the public safety and reliability of our distribution system. While Atmos Energy, with the support from each of its regulatory commissions, is accelerating the replacement of pipeline infrastructure, operating issues such as leaks, accidents, equipment problems, and incidents, including explosions and fire, could result in legal liability, repair, and remediation costs, increased operating costs, significant increased capital expenditures, regulatory fines and penalties, and other costs and a loss of customer confidence. We maintain liability and property insurance coverage in place for many of these hazards and risks. However, because some of our transmission pipeline and storage facilities are near or are in populated areas, any loss of human life or adverse financial results resulting from such events could be large. If these events were not fully covered by our general liability and property insurance, which policies are subject to certain limits and deductibles, our operations or financial results could be adversely affected.

If contracted gas supplies, interstate pipeline, and/or storage services are not available or delivered in a timely manner, our ability to meet our customers’ natural gas requirements may be impaired and our financial condition may be adversely affected.

In order to meet our customers’ annual and seasonal natural gas demands, we must obtain a sufficient supply of natural gas, interstate pipeline capacity, and storage capacity. If we are unable to obtain these, either from our suppliers’ inability to deliver the contracted commodity or the inability to secure replacement quantities, our financial condition and results of operations may be adversely affected. If a substantial disruption to or reduction in interstate natural gas pipelines’ transmission and storage capacity occurred due to operational failures or disruptions, legislative or regulatory actions, hurricanes, tornadoes, floods, extreme cold weather, terrorist or cyber-attacks, or acts of war, our operations or financial results could be adversely affected.

Our operations are subject to increased competition.

In residential and commercial customer markets, our distribution operations compete with other energy products, such as electricity and propane. Our primary product competition is with electricity for heating, water heating, and cooking. If customer ~~growth slows or existing customers choose to conserve their use of gas or choose another energy product, reduced gas purchases and customer billings could adversely impact our business.~~

Table of Contents

growth slows or existing customers choose to conserve their use of gas or choose another energy product, reduced gas purchases and customer billings could adversely impact our business.

In the case of industrial customers, such as manufacturing plants, adverse economic conditions, including higher gas costs, could cause these customers to use alternative sources of energy, such as electricity, or bypass our systems in favor of special competitive contracts with lower per-unit costs. Our pipeline and storage operations historically have faced limited competition from other existing intrastate pipelines and gas marketers seeking to provide or arrange transportation, storage, and other services for customers. The completion of new pipelines in our service area may increase the competition in this segment of our business.

Failure to attract and retain a qualified workforce could adversely affect our results of operations.

The competition for talent has become increasingly intense ~~and we may experience increased employee turnover due to a tightening labor market~~. If we are unable to recruit and retain an appropriately qualified workforce, the Company could encounter operating challenges primarily due to a loss of institutional knowledge and expertise, errors due to inexperience, or the lengthy time period typically required to adequately train replacement personnel. In addition, higher costs could result from loss of productivity, increased safety compliance issues, or cost of contract labor.

Additionally, our ability to operate is contingent on maintaining a healthy workforce and a safe working environment. As a provider of essential services, we have an obligation to provide natural gas services to customers. Incidents that impact the health and availability of our workforce could threaten the continuity of our business operations.

Natural disasters, adverse weather, terrorist activities, or other significant events could adversely affect our operations or financial results.

Natural disasters and adverse weather are always a threat to our assets and operations. In addition, the threat of terrorist activities could lead to increased economic instability and volatility in the price of natural gas that could affect our operations. Also, companies in our industry may face a heightened risk of exposure to actual acts of terrorism, which could subject our operations to increased risks. As a result, the Company's contractors, suppliers, and other business partners may be unable to fulfill their contractual obligations or the availability of insurance covering such risks may become more limited, which could increase the risk that an event could adversely affect our operations or financial results.

Technology and Cybersecurity Risks

The failure of technology may hinder the Company’s business operations and adversely affect its financial condition and results of operations.

Table of Contents

The Company uses Company-owned information technology and technology hosted by third parties to support critical functions including scheduling and dispatching of service technicians, automated meter reading systems, customer care and billing, operational plant logistics, management reporting, and external financial reporting. The failure of these or other similarly important technologies, or the Company’s inability to have these technologies supported, updated, expanded, or integrated into other technologies, could hinder its business operations and adversely impact its financial condition and results of operations.

Although the Company has, when possible, developed alternative sources of technology and built redundancy into its computer networks and tools, there can be no assurance that these efforts would protect against all potential issues related to the loss of any such technologies.

Cyber-attacks or acts of cyber-terrorism could disrupt our business operations and information technology systems or result in the loss or exposure of confidential or sensitive customer, employee or Company information.

Our business operations and information technology systems may be vulnerable to an attack by individuals or organizations intending to disrupt our business operations and information technology systems. Disruption of those systems could adversely impact our ability to safely deliver natural gas to our customers, operate our pipeline and storage systems, or serve our customers timely. Further, any attack on our technology systems that would result in the unauthorized release of confidential or sensitive data could have a material adverse effect on our business reputation, increase our costs, and expose us to material legal claims and liability. The Company has implemented policies, procedures, and controls to identify, protect, detect, and respond to cyberattacks or acts of terrorism. However, these measures may be insufficient or become ineffective, and there are no assurances that cybersecurity breaches or acts of terrorism will not impact our business operations and strategy, results of operations, and financial condition in the future. Even though we have insurance coverage in place for many of these cyber-related risks, if such an attack or act of terrorism were to occur, our operations and financial results could be adversely affected to the extent not fully covered by such insurance coverage.

Compliance with and changes in cybersecurity requirements have a cost and operational impact on our business, and failure to comply with such laws and regulations could adversely impact our reputation, results of operations, financial condition, and/or cash flows.

Table of Contents

As cyber-attacks are becoming more sophisticated, U.S. government warnings have indicated that critical infrastructure assets, including pipeline infrastructure, may be specifically targeted by certain groups. In recent years, the U.S. government has issued directives that require critical pipeline owners to comply with mandatory reporting measures, designate a cybersecurity coordinator, provide vulnerability assessments, and ensure compliance with certain cybersecurity requirements. Such directives or other requirements may require expenditure of significant additional resources to respond to cyber-attacks, to continue to modify or enhance protective measures, or to assess, investigate, and remediate any critical infrastructure security vulnerabilities. Any failure to comply with such government regulations or failure in our cybersecurity protective measures may result in enforcement actions that may have a material adverse effect on our business, results of operations, and financial condition. In addition, there is no certainty that costs incurred related to securing against threats will be recovered through rates.

Climate Risks

Adverse weather conditions could affect our operations or financial results.

We have weather-normalized rates for approximately 97 percent of our residential and commercial revenues in our distribution operations, which substantially mitigates the adverse effects of warmer-than-normal weather for meters in those service areas. However, there is no assurance that we will continue to receive such regulatory protection from adverse weather in our rates in the future. The loss of such weather-normalized rates could have an adverse effect on our operations and financial results. In addition, our operating results may continue to vary somewhat with the actual temperatures during the winter heating season. Additionally, sustained cold weather could challenge our ability to adequately meet customer demand in our operations.

Legislation to reduce or eliminate greenhouse gas emissions or fossil fuels could increase our operating costs, adversely affecting our financial results, growth, cash flows, and results of operations.

Six of the eight states in which we operate have passed legislation to prevent local governments from limiting the types of energy available to customers. However, federal, regional, and/or state legislative and/or regulatory initiatives may attempt to control or limit greenhouse gas emissions, such as carbon dioxide and methane, by requiring the adoption of new infrastructure or technology to limit greenhouse gas emissions, limiting our ability to serve new or existing customers, imposing costs or restrictions on end users of natural gas, or assessing additional charges to fund energy efficiency activities. Such laws or regulations could adversely affect our business, results of operations, and cash flows if the costs we incur to comply with these laws or regulations are not recovered or if the cost of providing natural gas services becomes prohibitively expensive, leading to a reduction in the demand for natural gas or fuel-switching to alternate sources of energy.

Table of Contents

The operations and financial results of the Company could be adversely impacted as a result of climate change.

Climate change may result in a reduction in the demand for natural gas or cause shifts in the population of our service territories which could adversely impact the economic outlook for our service territories. These occurrences could adversely impact our financial results, growth, cash flows, and results of operations.

It could also result in more frequent and more severe weather events, such as hurricanes and tornadoes, which could increase our costs to repair damaged facilities and restore service to our customers or impact the cost of gas. If we were unable to deliver natural gas to our customers, our financial results would be impacted by lost revenues, and we generally would have to seek approval from regulators to recover restoration costs. To the extent we would be unable to recover those costs, or if higher rates resulting from our recovery of such costs would result in reduced demand for our services, our future business, financial condition, or financial results could be adversely impacted.

Financial, Economic, and Market Risks

Our growth in the future may be limited by the nature of our business, which requires extensive capital spending.

Our operations are capital-intensive. We must make significant capital expenditures on a long-term basis to modernize our distribution and transmission system and to comply with the safety rules and regulations issued by the regulatory authorities responsible for the service areas we operate. In addition, we must continually build new capacity to serve the growing needs of the communities we serve. The magnitude of these expenditures may be affected by a number of factors, including new policy and regulations, and the general state of the economy.

The liquidity required to fund our working capital, capital expenditures, and other cash needs is provided from a combination of internally generated cash flows and external debt and equity financing. The cost and availability of borrowing funds from third party lenders or issuing equity is dependent on the liquidity of the credit markets, interest rates and other market conditions. This in turn may limit the amount of funds we can invest in our infrastructure.

The Company is dependent on continued access to the credit and capital markets to execute our business strategy.

Our long-term debt is currently rated as “investment grade” by Standard & Poor’s Corporation and Moody’s Investors Service, Inc. Similar to most companies, we rely upon access to both short-term and long-term credit and capital markets to satisfy our liquidity requirements. If adverse credit conditions were to cause a significant limitation on our access to the private credit and public capital markets, we could see a reduction in our liquidity. A significant reduction in our liquidity could in turn trigger a negative change in our ratings outlook or even a reduction in our credit ratings by one or more of the credit rating agencies. Such a downgrade could further limit our access to private credit and/or public capital markets and increase our costs of borrowing.

Table of Contents

satisfy our liquidity requirements. If adverse credit conditions were to cause a significant limitation on our access to the private credit and public capital markets, we could see a reduction in our liquidity. A significant reduction in our liquidity could in turn trigger a negative change in our ratings outlook or even a reduction in our credit ratings by one or more of the credit rating agencies. Such a downgrade could further limit our access to private credit and/or public capital markets and increase our costs of borrowing.

While we believe we can meet our capital requirements from our operations and the sources of financing available to us, we can provide no assurance that we will continue to be able to do so in the future. The future effects on our business, liquidity, and financial results of a deterioration of current conditions in the credit and capital markets could be material and adverse to us, both in the ways described above or in other ways that we do not currently anticipate.

We are exposed to market risks that are beyond our control, which could adversely affect our financial results.

We are subject to market risks beyond our control, including (i) commodity price volatility caused by market supply and demand dynamics, counterparty performance, or counterparty creditworthiness and (ii) interest rate risk. We are generally insulated from commodity price risk through our purchased gas cost mechanisms. With respect to interest rate risk, increases in interest rates could adversely affect our future financial results to the extent that we do not recover our actual interest expense in our rates.

The concentration of our operations in the State of Texas exposes our operations and financial results to economic conditions, weather patterns, and regulatory decisions in Texas.

Approximately 75 percent of our consolidated operations are located in the State of Texas. This concentration of our business in Texas means that our operations and financial results may be significantly affected by changes in the Texas economy in general, weather patterns, and regulatory decisions by state and local regulatory authorities in Texas.

A deterioration in economic conditions could adversely affect our customers and negatively impact our financial results.

Any adverse changes in economic conditions in the states in which we operate could adversely affect the financial resources of many domestic households. As a result, our customers could seek to use less gas and it may be more difficult for them to pay their gas bills. This would likely lead to slower collections and higher than normal levels of accounts receivable. This, in turn, could increase our financing requirements. Additionally, should economic conditions deteriorate, our industrial customers could seek alternative energy sources, which could result in lower transportation volumes.

Table of Contents

Increased gas costs could adversely impact our customer base and customer collections and increase our level of indebtedness.

Rapid increases in the costs of purchased gas would cause us to experience a significant increase in short-term or long-term debt. We must pay suppliers for gas when it is purchased, which can be significantly in advance of when these costs may be recovered through the collection of monthly customer bills for gas delivered. Increases in purchased gas costs also slow our natural gas distribution collections as customers may delay the payment of their gas bills, leading to higher than normal accounts receivable. This could result in higher short-term debt levels, greater collection efforts, and increased bad debt expense.

Our pension and other postretirement benefit plans are subject to investment and interest rate risk that could negatively impact our financial condition.

We have pension and other postretirement benefit plans that provide benefits to many of our employees and retirees. Costs of providing benefits and related- funding requirements of these plans are subject to changes in the market value of the assets that fund the plans. The funded status of the plans and the related costs reflected in the Company’s financial statements are affected by various factors, which are subject to an inherent degree of uncertainty, including economic conditions, financial market performance, interest rates, life expectancies, and demographics. Poor investment returns or lower interest rates may necessitate accelerated funding of the plans to meet minimum federal government requirements, which could have an adverse impact on the Company’s financial condition and results of operations if such costs are not ultimately recoverable.


ITEM 1B.			Unresolved Staff Comments.

Not applicable.


ITEM 1C.			Cybersecurity.

We continuously assess our risk of cyber threats to adapt quickly to the ever-changing challenges and risks surrounding cybersecurity. Atmos Energy has implemented policies, procedures, and controls to identify, protect, detect, and respond to cyberattacks or acts of online terrorism. Atmos Energy is also subject to the U.S. Department of Homeland Security Transportation Security Administration (TSA) security directive for our natural gas pipeline monitoring and control systems.

Table of Contents

cyberattacks or acts of online terrorism. Atmos Energy is also subject to the U.S. Department of Homeland Security Transportation Security Administration (TSA) security directive for our natural gas pipeline monitoring and control systems.

The potential impact of cybersecurity risks on our business operations, results of operations, or financial condition is discussed in the “Technology and Cybersecurity Risks” section of Item 1A “Risk Factors.” We have not had any material cybersecurity breaches or incidents and have not incurred any material expenses, penalties, or settlement costs related to any cybersecurity breaches or incidents. However, measures that we take to identify, protect, detect, and respond from cybersecurity breaches or incidents may be insufficient or become ineffective, and there are no assurances that cybersecurity breaches or incidents will not impact our business operations and strategy, results of operations, and financial condition in the future.

The following describes our risk management and strategy and corporate governance as it pertains to cybersecurity.

Risk Management and Strategy

Atmos Energy’s cybersecurity program leverages the National Institute of Standards and Technology (NIST) Cybersecurity Framework (CSF) in its design of controls intended to reduce the risk and potential impact of cybersecurity incidents. This comprehensive approach encompasses continuous monitoring, risk assessments, a cybersecurity incident response plan, and regular evaluations to align our practices with industry standards. Additionally, we actively engage in cybersecurity risk management practices and continually improve procedures and practices to support the continued safe and reliable delivery of natural gas to our customers.

The identification and management of cybersecurity risk is a component of our Integrated Risk Management process, which applies adaptive process improvement to help us respond to the changing cybersecurity landscape. Additionally, we use third parties to enhance our collective capability to monitor, detect, and respond to cybersecurity incidents. Further, we maintain collaborative relationships with government officials, law enforcement, and industry peers to keep informed of trends and potential cyber tactics. Finally, we maintain cybersecurity insurance coverage that we believe is appropriate for the size and complexity of our business.

We have an information technology cybersecurity incident response plan to manage cybersecurity incidents. The plan provides guidelines for actions in response to cyber security incidents that may occur at or otherwise affect Atmos Energy. These guidelines include notification to a cross-functional management team to assess incident materiality and an escalation process to members of our senior management team and our Board of Directors. This plan, which is periodically reviewed and tested, is supported by third parties to provide guidance and support to our cybersecurity management team.

Table of Contents

We also address cybersecurity risks associated with third-party service providers, including those in our supply chain or who have access to our data or our information technology systems. Atmos Energy currently conducts cyber assessments on potential vendors that will have access to information technology systems, data or facilities that house such systems or data. Following approval, those vendors are contractually required to manage their cybersecurity risks and provide notification in the event of a cybersecurity incident.

Governance

Our Vice President and Chief Information Officer (CIO), who has over two decades of experience in information technology, is responsible for overseeing our cybersecurity program. The CIO oversees an IT Information security team responsible for our overall cybersecurity program. This team is comprised of several IT professionals with varying degrees of cybersecurity experience and is led by our Director – Cybersecurity who has over 30 years of experience in information technology and cybersecurity. The Director – Cybersecurity reports to the CIO, who reports to the Senior Vice President and Chief Financial Officer.

The CIO is a member of the Company’s Risk Management and Compliance Committee (RMCC). The RMCC is comprised of members from the senior leadership team and is responsible for overseeing enterprise-wide risk management across all categories, including cybersecurity. The RMCC is overseen by the Company’s Management Committee, which is comprised of the President and Chief Executive Officer, Senior Vice President and Chief Financial Officer, Senior Vice President, Utility Operations, Senior Vice President, General Counsel & Corporate Secretary, ~~and~~ Senior Vice President, Human Resources, and Senior Advisor. The CIO provides regular cybersecurity updates to the Audit Committee of the Board of Directors and the Management Committee. These updates address prevention, detection, mitigation, and remediation of cybersecurity incidents, as well as risks, threats, and the threat landscape.

The Audit Committee of the Board of Directors oversees the company's cybersecurity risks. Additionally, our Board of Directors periodically engages with third-party advisors to provide further education about cybersecurity risks.

2019

Table of Contents


ITEM 2.			Properties.

To manage the integrity and safety of our natural gas distribution and transmission systems, consistent with PHMSA regulations, we have integrity management programs that integrate information sources and data, identify risks to infrastructure integrity, rank risks, and designate measures and actions to reduce or mitigate risks as appropriate. These programs take into consideration numerous input factors and no single factor is determinative in our decision to take mitigative actions on our distribution or transmission pipeline systems. Based upon these programs, along with the oversight of state regulators responsible for adopting and enforcing the federal pipeline safety regulations, we believe that our distribution and transmission pipeline systems are suitable and adequate for our purposes.

Distribution, transmission, and related assets

In our distribution segment, we owned an aggregate of 74approximately 76,~~596~~000 miles of underground distribution and transmission mains throughout our distribution systems. These mains are located on easements or rights-of-way. We maintain our mains through a program of continuous inspection and repair and believe that our system of mains is in good condition. Through our pipeline and storage segment we owned approximately 5,~~682~~700 miles of gas transmission lines.

Storage Assets

We own underground gas storage facilities in several states to supplement the supply of natural gas in periods of peak demand. The following table summarizes certain information regarding our underground gas storage facilities at September 30, ~~2024~~2025:

State

Working Capacity(Mcf)

Base Gas(Mcf)(1)

TotalCapacity(Mcf)

MaximumDaily DeliveryCapability(Mcf)

Distribution Segment

Kentucky

7,956,991

9,562,283

17,519,274

~~146~~151,~~660~~719

Kansas

3,239,000

2,300,000

5,539,000

32,000

Mississippi

1,907,571

2,442,917

4,350,488

29,136

Total

13,103,562

14,305,200

27,408,762

~~207~~212,~~796~~855

Pipeline and Storage Segment

Texas

5352,~~083~~761,~~549~~317

1920,~~678~~155,025

72,~~761~~916,~~574~~342

21,~~460~~653,000

Louisiana

411,040

256,900

667,940

56,000

Total

53,~~494~~172,~~589~~357

1920,~~934~~411,925

73,~~429~~584,~~514~~282

21,~~516~~709,000

Total

66,~~598~~275,~~151~~919

34,~~240~~717,125

100,~~838~~993,~~276~~044

21,~~723~~921,~~796~~855

(1)Base gas represents the volume of gas that must be retained in a facility to maintain reservoir pressure.

Additionally, we contract for storage service in underground storage facilities on many of the interstate and intrastate pipelines serving us to supplement our proprietary storage capacity. The following table summarizes our contracted storage capacity at September 30, ~~2024~~2025:

Segment	Division/Company	MaximumStorageQuantity(MMBtu)	MaximumDailyWithdrawalQuantity(Mcf)(1)
Distribution Segment
	Colorado-Kansas Division	6,343,728	147,692
	Kentucky/Mid-States Division	8,175,103	226,320
	Louisiana Division	2,594,875	177,765
	Mid-Tex Division	6,000,000	190,000
	Mississippi Division	5,799,536	222,764
	West Texas Division	6,500,000	246,000
Total		35,413,242	1,210,541
Pipeline and Storage Segment
	Trans Louisiana Gas Pipeline, Inc.	1,500,000	71,250
Total Contracted Storage Capacity		36,913,242	1,281,791

Table of Contents


Segment	Division/Company	Maximum Storage Quantity (MMBtu)	Maximum Daily Withdrawal Quantity (Mcf)(1)
Distribution Segment
	Colorado-Kansas Division	7,343,728	157,692
	Kentucky/Mid-States Division	11,699,976	281,320
	Louisiana Division	2,594,875	177,765
	Mid-Tex Division	46,771,428	1,260,000
	Mississippi Division	5,799,536	222,764
	West Texas Division	6,500,000	246,000
Total		80,709,543	2,345,541
Pipeline and Storage Segment
	Trans Louisiana Gas Pipeline, Inc.	1,500,000	71,250

Total Contracted Storage Capacity		82,209,543	2,416,791

(1)Maximum daily withdrawal quantity (MDWQ) amounts will fluctuate depending upon the season and the month. Unless otherwise noted, MDWQ amounts represent the MDWQ amounts as of November 1, which is the beginning of the winter heating season.

Table of Contents


ITEM 3.			Legal Proceedings.

See Note 14 to the consolidated financial statements, which is incorporated in this Item 3 by reference.


ITEM 4.			Mine Safety Disclosures.

Not applicable.

PART II


ITEM 5.			Market for Registrant’s Common Equity, Related Stockholder Matters and Issuer Purchases of Equity Securities.

Our stock trades on the New York Stock Exchange under the trading symbol “ATO.” The dividends paid per share of our common stock was $3.48 for fiscal ~~2024 and 2023 are listed below~~2025.

	Fiscal 2024		Fiscal 2023
Quarter ended:
December 31	$	0.805	$	0.740
March 31	0.805		0.740
June 30	0.805		0.740
September 30	0.805		0.740
	$	3.22	$	2.96

Dividends are payable at the discretion of our Board of Directors out of legally available funds. The Board of Directors typically declares dividends in the same fiscal quarter in which they are paid. As of October 31, 2025, there were 8,446 holders of record of our common stock. Future payments of dividends, and the amounts of these dividends, will depend on our financial condition, results of operations, capital requirements, and other factors. We sold no securities during fiscal 2025 that were not registered under the Securities Act of 1933, as amended.

Dividends are payable at the discretion of our Board of Directors out of legally available funds. The Board of Directors typically declares dividends in the same fiscal quarter in which they are paid. As of October 31, 2024, there were 8,968 holders of record of our common stock. Future payments of dividends, and the amounts of these dividends, will depend on our financial condition, results of operations, capital requirements, and other factors. We sold no securities during fiscal 2024 that were not registered under the Securities Act of 1933, as amended.

Table of Contents

Performance Graph

The performance graph and table below compares the yearly percentage change in our total return to shareholders for the last five fiscal years with the total return of the S&P 500 Stock Index (S&P 500) and the total return of the S&P 500 Utilities Industry Index. The graph and table below assume that $100.00 was invested on September 30, ~~2019~~2020 in our common stock, the S&P 500 and the S&P 500 Utilities Industry Index, as well as a reinvestment of dividends paid on such investments throughout the period.

Comparison of Five-Year Cumulative Total Return

among Atmos Energy Corporation, S&P 500 Index and

S&P 500 Utilities Industry Index

Cumulative Total Return

9/30/2019

9/30/2020

9/30/2021

9/30/2022

9/30/2023

9/30/2024

9/30/2020

9/30/2021

9/30/2022

9/30/2023

9/30/2024

9/30/2025

Atmos Energy Corporation

100.00

8594.7768

81112.2114

96119.1961

~~102~~161.5900

~~138~~202.1067

S&P 500 Stock Index

100.00

~~115~~130.1501

~~149~~109.7089

~~126~~133.5465

~~153~~182.8923

~~209~~214.8430

S&P 500 Utilities Stock Index

100.00

95111.0301

~~105~~117.4920

~~111~~108.3898

~~103~~154.5655

~~146~~171.8786

Table of Contents

The following table sets forth the number of securities authorized for issuance under our equity compensation plans at September 30, ~~2024~~2025.

Number ofsecurities to be issuedupon exercise ofoutstanding options, warrants and rights

Weighted-averageexercise price ofoutstanding options,warrants and rights

Number of securities remainingavailable for future issuanceunder equity compensationplans (excluding securitiesreflected in column (a))

(a)

(b)

(c)

Equity compensation plans approved by security holders:

1998 Long-Term Incentive Plan

~~737~~703,~~219~~176

(1)

—

~~407~~2,~~966~~166,340

Total equity compensation plans approved by security holders

~~737~~703,~~219~~176

—

~~407~~2,~~966~~166,340

Equity compensation plans not approved by security holders

—

Total

~~737~~703,~~219~~176

—

~~407~~2,~~966~~166,340

(1)Comprised of a total of ~~259~~229,~~666~~681 time-lapse restricted stock units, ~~215~~151,~~515~~684 director share units, and ~~262~~321,~~038~~811 performance-based restricted stock units at the target level of performance granted under our 1998 Long-Term Incentive Plan.


ITEM 6.			Reserved.


ITEM 7.			Management’s Discussion and Analysis of Financial Condition and Results of Operations.

INTRODUCTION

This section provides management’s discussion of the financial condition, changes in financial condition, and results of operations of Atmos Energy Corporation and its consolidated subsidiaries with specific information on results of operations and liquidity and capital resources. It includes management’s interpretation of our financial results, the factors affecting these results, the major factors expected to affect future operating results, and future investment and financing plans. This discussion should be read in conjunction with our consolidated financial statements and notes thereto.

Several factors exist that could influence our future financial performance, some of which are described in Item 1A above, “Risk Factors”. They should be considered in connection with evaluating forward-looking statements contained in this report or otherwise made by or on behalf of us since these factors could cause actual results and conditions to differ materially from those set out in such forward-looking statements.

Cautionary Statement for the Purposes of the Safe Harbor under the Private Securities Litigation Reform Act of 1995

The statements contained in this Annual Report on Form 10-K may contain “forward-looking statements” within the meaning of Section 27A of the Securities Act of 1933 and Section 21E of the Securities Exchange Act of 1934. All statements other than statements of historical fact included in this Report are forward-looking statements made in good faith by us and are intended to qualify for the safe harbor from liability established by the Private Securities Litigation Reform Act of 1995. When used in this Report, or any other of our documents or oral presentations, the words “anticipate”, “believe”, “estimate”, “expect”, “forecast”, “goal”, “intend”, “objective”, “plan”, “projection”, “seek”, “strategy”, or similar words are intended to identify forward-looking statements. Such forward-looking statements are subject to risks and uncertainties that could cause actual results to differ materially from those expressed or implied in the statements relating to our strategy, operations, markets, services, rates, recovery of costs, availability of gas supply, and other factors. These risks and uncertainties include the following: federal, state, and local regulatory and political trends and decisions, including the impact of rate proceedings before various state regulatory commissions; increased federal regulatory oversight and potential penalties; possible increased federal, state, and local regulation of the safety of our operations; possible significant costs and liabilities resulting from pipeline integrity and other similar programs and related repairs; the inherent hazards and risks involved in distributing, transporting, and storing natural gas; the availability and accessibility of contracted gas supplies, interstate pipeline, and/or storage services; increased competition from energy suppliers and alternative forms of energy; failure to attract and retain a qualified workforce; natural disasters, adverse weather, terrorist activities, or other events and other risks and uncertainties discussed herein, all of which are difficult to predict and many of which are beyond our control; failure of technology that affects the Company's business operations; the threat of cyber-attacks or acts of cyber-terrorism that could disrupt our business operations and information technology systems or result in the loss or exposure of confidential or sensitive customer, employee, or Company information; the impact of new cybersecurity compliance requirements; adverse weather conditions; the impact of legislation to

Table of Contents

~~information; the impact of new cybersecurity compliance requirements; adverse weather conditions; the impact of legislation to~~ reduce or eliminate greenhouse gas emissions or fossil fuels; the impact of climate change; the capital-intensive nature of our business; our ability to continue to access the credit and capital markets to execute our business strategy; market risks beyond our control affecting our risk management activities, including commodity price volatility, counterparty performance or creditworthiness, and interest rate risk; the concentration of our operations in Texas; the impact of adverse economic conditions on our customers; changes in the availability and price of natural gas; and increased costs of providing health care benefits, along with pension and postretirement health care benefits and increased funding requirements. Accordingly, while we believe these forward-looking statements to be reasonable, there can be no assurance that they will approximate actual experience or that the expectations derived from them will be realized. Further, we undertake no obligation to update or revise any of our forward-looking statements whether as a result of new information, future events or otherwise.

OVERVIEW

Atmos Energy's vision is to be the safest provider of natural gas services. Our commitment to this vision requires significant levels of capital spending to modernize our natural gas distribution system and operating costs to deliver natural gas safely and reliably and in compliance with the various safety regulations impacting our business. We have the ability to begin recovering a significant portion of our expenditures timely through rate designs and mechanisms that reduce or eliminate regulatory lag and separate the recovery of our approved rate from customer usage patterns. The execution of our capital spending program, the ability to recover these expenditures timely and our ability to access the capital markets to satisfy our financing needs are the primary drivers that affect our financial performance.

We anticipate making significant capital expenditures for the foreseeable future to modernize our distribution and transmission system, to comply with the safety rules and regulations issued by the regulatory authorities responsible for the service areas in which we operate, and to prepare to serve the growing needs of the communities we serve. Between fiscal years 2026 and 2030, we anticipate spending approximately $26 billion, with more than 80 percent dedicated to safety and reliability spending. The magnitude and allocation of these expenditures may be affected by factors such as new policy and regulations, population growth, and increased labor and materials costs. Although we believe these costs are ultimately recoverable through our rates based on the regulatory frameworks currently available to us, full recovery is not assured.

CRITICAL ACCOUNTING POLICIES

Our consolidated financial statements were prepared in accordance with accounting principles generally accepted in the United States. Preparation of these financial statements requires us to make estimates and judgments that affect the reported amounts of assets, liabilities, revenues, and expenses and the related disclosures of contingent assets and liabilities. We base our estimates on historical experience and various other assumptions that we believe to be reasonable under the circumstances. Actual results may differ from estimates.

Our significant accounting policies are discussed in Note 2 to our consolidated financial statements. The accounting policies discussed below are both important to the presentation of our financial condition and results of operations and require management to make difficult, subjective, or complex accounting estimates. Accordingly, these critical accounting policies are reviewed periodically by the Audit Committee of the Board of Directors.


Critical Accounting Policy	Summary of Policy	Factors Influencing Application of the Policy
Regulation	Our distribution and pipeline operations meet the criteria of a cost-based, rate-regulated entity under accounting principles generally accepted in the United States. Accordingly, the financial results for these operations reflect the effects of the ratemaking and accounting practices and policies of the various regulatory commissions to which we are subject. As a result, certain costs that would normally be expensed under accounting principles generally accepted in the United States are permitted to be capitalized or deferred on the balance sheet because it is probable they can be recovered through rates. Further, regulation may impact the period in which revenues or expenses are recognized. The amounts expected to be recovered or recognized are based upon historical experience and our understanding of the regulations. Discontinuing the application of this method of accounting for regulatory assets and liabilities or changes in the accounting for our various regulatory mechanisms could significantly increase our operating expenses as fewer costs would likely be capitalized or deferred on the balance sheet, which could reduce our net income.	Decisions of regulatory authorities Issuance of new regulations or regulatory mechanisms Assessing that the recoverability of deferred costs and utility assets is probable Continuing to meet the criteria of a cost-based, rate regulated entity for accounting purposes

Table of Contents


Critical Accounting Policy	Summary of Policy	Factors Influencing Application of the Policy
Pension and other postretirement plans	Pension and other postretirement plan costs and liabilities are determined on an actuarial basis using a September 30 measurement date and are affected by numerous assumptions and estimates including the market value of plan assets, estimates of the expected return on plan assets, assumed discount rates, and current demographic and actuarial mortality data. The assumed discount rate and the expected return are the assumptions that generally have the most significant impact on our pension costs and liabilities. The assumed discount rate, the assumed health care cost trend rate, and assumed rates of retirement generally have the most significant impact on our postretirement plan costs and liabilities. The discount rate is utilized principally in calculating the actuarial present value of our pension and postretirement obligations and net periodic pension and postretirement benefit plan costs. When establishing our discount rate, we consider high quality corporate bond rates based on bonds available in the marketplace that are suitable for settling the obligations, changes in those rates from the prior year, and the implied discount rate that is derived from matching our projected benefit disbursements with currently available high quality corporate bonds. The expected long-term rate of return on assets is utilized in calculating the expected return on plan assets component of our annual pension and postretirement plan costs. We estimate the expected return on plan assets by evaluating expected bond returns, equity risk premiums, asset allocations, the effects of active plan management, the impact of periodic plan asset rebalancing, and historical performance. We also consider the guidance from our investment advisors in making a final determination of our expected rate of return on assets. To the extent the actual rate of return on assets realized over the course of a year is greater than or less than the assumed rate, that year’s annual pension or postretirement plan costs are not affected. Rather, this gain or loss reduces or increases future pension or postretirement plan costs over a period of approximately ten to twelve years. The market-related value of our plan assets represents the fair market value of the plan assets, adjusted to smooth out short-term market fluctuations over a five-year period. The use of this methodology will delay the impact of current market fluctuations on the pension expense for the period. We estimate the assumed health care cost trend rate used in determining our postretirement net expense based upon our actual health care cost experience, the effects of recently enacted legislation and general economic conditions. Our assumed rate of retirement is estimated based upon our annual review of our participant census information as of the measurement date.	General economic and market conditions Assumed investment returns by asset class Assumed future salary increases Assumed discount rate Projected timing of future cash disbursements Health care cost experience trends Participant demographic information Actuarial mortality assumptions Impact of legislation Impact of regulation

RESULTS OF OPERATIONS

Overview

Atmos Energy's vision is to be the safest provider of natural gas services. Our commitment to this vision requires significant levels of capital spending to modernize our natural gas distribution system and operating costs to deliver natural gas safely and reliably and in full compliance with the various safety regulations impacting our business. We have the ability to begin recovering a significant portion of our expenditures timely through rate designs and mechanisms that reduce or eliminate regulatory lag and separate the recovery of our approved rate from customer usage patterns. The execution of our capital spending program, the ability to recover these expenditures timely and our ability to access the capital markets to satisfy our financing needs are the primary drivers that affect our financial performance.

The following table details our consolidated net income by segment during the last three fiscal years:


	For the Fiscal Year Ended September 30
	2025		2024		2023
	(In thousands)
Distribution segment	$	746,781	$	671,413	$	580,397
Pipeline and storage segment	451,973		371,482		305,465
Net income	$	1,198,754	$	1,042,895	$	885,862

During fiscal 2025, we recorded net income of $1,198.8 million, or $7.46 per diluted share, compared to net income of $1,042.9 million, or $6.83 per diluted share in the prior year. The year-over-year increase in net income of $155.9 million largely reflects positive rate outcomes driven by safety and reliability spending. Additionally, our fiscal 2025 results were

Table of Contents

	For the Fiscal Year Ended September 30
	2024		2023		2022
	(In thousands)
Distribution segment	$	671,413	$	580,397	$	521,977
Pipeline and storage segment	371,482		305,465		252,421
Net income	$	1,042,895	$	885,862	$	774,398

favorably impacted by $26.2 million as a result of Texas legislation that became effective during the third quarter of fiscal 2025 related to infrastructure spending. These increases were partially offset by higher bad debt expense, increased employee-related costs, depreciation and property tax expenses, and higher spending on safety and compliance related activities.

During ~~fiscal~~the ~~2024,~~year weended ~~recorded~~September 30, ~~net~~2025, ~~income~~we ofimplemented ~~$1,042.9~~ratemaking ~~million,~~regulatory oractions ~~$6.83~~which ~~per~~resulted ~~diluted~~in ~~share,~~an ~~compared~~increase toin ~~net~~annual operating income of $~~885~~333.96 million~~, or $6~~.10 ~~per~~Excluding ~~diluted~~the ~~share~~impact inof the ~~prior~~refund ~~year.~~of ~~The~~excess ~~year-over-year~~deferred ~~increase in net~~ income oftaxes ~~$157.0~~resulting ~~million~~from ~~largely~~previously ~~reflects~~enacted ~~positive~~tax ~~rate~~reform ~~outcomes driven by safety and reliability spending. Additionally~~legislation, our total fiscal ~~2024~~2025 ~~results~~rate outcomes were ~~favorably impacted by~~ $21322.18 million. asAdditionally, awe ~~result~~had ofratemaking ~~legislation~~efforts ~~that~~in ~~became~~progress ~~effective~~at ~~during~~September 30, ~~the~~2025, ~~first~~seeking ~~quarter~~a oftotal ~~fiscal~~increase ~~2024~~in toannual ~~reduce~~operating ~~property~~income ~~tax~~of ~~expenses in Texas and~~ $13231.91 million ~~as a result of a change to our bad debt recovery mechanism in Mississippi~~. ~~These increases were partially offset by increased employee-related costs, depreciation expense, and interest expense.~~

During ~~the~~fiscal year ~~ended September 30~~2025, ~~2024,~~ we ~~implemented~~refunded ~~ratemaking regulatory actions which resulted in an increase in annual operating income of~~ $~~376~~78.38 million. ~~Excluding~~in ~~the impact of the refund of~~ excess deferred ~~income~~tax ~~taxes~~liabilities ~~resulting~~to ~~from~~customers. ~~previously~~These ~~enacted~~refunds ~~tax~~also ~~reform~~reduced ~~legislation,~~ our ~~total~~income ~~fiscal~~tax ~~2024 rate outcomes were $307.1 million. Additionally~~expense, weresulting ~~had ratemaking efforts~~ in ~~progress~~an atimmaterial ~~September 30,~~impact ~~2024,~~to ~~seeking~~our afiscal ~~total~~2025 ~~increase~~and in2024 ~~annual operating income of $218~~results.~~0 million.~~

~~During~~Capital ~~fiscal~~expenditures ~~year~~for ~~2024,~~fiscal we2025 ~~refunded~~were $~~133~~3.6 ~~million~~billion. inApproximately ~~excess~~87 ~~deferred~~percent ~~tax~~was ~~liabilities~~invested to ~~customers.~~improve ~~These~~the ~~refunds~~safety ~~also~~and ~~reduced~~reliability of our ~~income~~distribution ~~tax~~and ~~expense~~transportation systems, ~~resulting~~with ina ansignificant ~~immaterial~~portion ~~impact~~of tothis ~~our~~investment ~~fiscal~~incurred ~~2024~~under ~~and~~regulatory ~~2023~~mechanisms ~~results~~that reduce regulatory lag to six months or less.

~~Capital~~During ~~expenditures~~fiscal ~~for~~2025, ~~fiscal~~we ~~2024~~completed ~~were~~approximately $21.98 billion of long-term debt and equity financing. ~~Approximately~~As 83of ~~percent~~September 30, 2025, our equity capitalization was ~~invested~~60.3 topercent. ~~improve~~As ~~the~~of ~~safety~~September 30, ~~and~~2025, ~~reliability~~we had approximately $4.9 billion in total liquidity, consisting of ~~our~~$202.7 ~~distribution~~million in cash and ~~transportation~~cash ~~systems~~equivalents, ~~with~~$1,558.5 amillion ~~significant~~in ~~portion~~funds ofavailable ~~this~~through ~~investment~~equity ~~incurred~~forward ~~under~~sales ~~regulatory~~agreements, ~~mechanisms~~and ~~that~~$3,094.4 ~~reduce~~million ~~regulatory~~in ~~lag~~undrawn tocapacity ~~six~~under ~~months~~our orcredit ~~less~~facilities.

During fiscal 2024, we completed approximately $2.0 billion of long-term debt and equity financing. As of September 30, 2024, our equity capitalization was 61.0 percent. As of September 30, 2024, we had approximately $4.8 billion in total liquidity, consisting of $307.3 million in cash and cash equivalents, $1,380.6 million in funds available through equity forward sales agreements, and $3,094.4 million in undrawn capacity under our credit facilities.

Distribution Segment

The distribution segment is comprised of our regulated natural gas distribution and related sales operations in eight states. The primary factors that impact the results of our distribution operations are our ability to earn our authorized rates of return, competitive factors in the energy industry, and economic conditions in our service areas.

Our ability to earn our authorized rates is based primarily on our ability to improve the rate design in our various ratemaking jurisdictions to minimize regulatory lag and, ultimately, separate the recovery of our approved rates from customer usage patterns. Improving rate design is a long-term process and is further complicated by the fact that we operate in multiple rate jurisdictions. The “Ratemaking Activity” section of this Form 10-K describes our current rate strategy, progress towards implementing that strategy, and recent ratemaking initiatives in more detail. During fiscal ~~2024~~2025, we completed regulatory proceedings in our distribution segment resulting in a $~~266~~256.84 million increase in annual operating income. Excluding the impact of the refund of excess deferred income taxes resulting from previously enacted tax reform legislation, our total fiscal ~~2024~~2025 annualized rate outcomes in our distribution segment were $~~234~~245.56 million.

Our distribution operations are also affected by the cost of natural gas. We are generally able to pass the cost of gas through to our customers without markup under purchased gas cost adjustment mechanisms; therefore, increases in the cost of gas are offset by a corresponding increase in revenues. Revenues in our Texas and Mississippi service areas include franchise fees and gross receipts taxes, which are calculated as a percentage of revenue (inclusive of gas costs). Therefore, the amount of these taxes included in revenues is influenced by the cost of gas and the level of gas sales volumes. We record the associated tax expense as a component of taxes, other than income.

The cost of gas typically does not have a direct impact on our operating income because these costs are recovered through our purchased gas cost adjustment mechanisms. However, higher gas costs may adversely impact our accounts receivable collections, resulting in higher bad debt expense. This risk is currently mitigated by rate design that allows us to collect from our customers the gas cost portion of our bad debt expense on approximately 89 percent of our residential and commercial revenues. Additionally, higher gas costs may require us to increase borrowings under our credit facilities, resulting in higher interest expense. Finally, higher gas costs, as well as competitive factors in the industry and general economic conditions may cause customers to conserve or, in the case of industrial consumers, to use alternative energy sources.

Review of Financial and Operating Results

Financial and operational highlights for our distribution segment for the fiscal years ended September 30, 2025, 2024, and 2023 are presented below.

Table of Contents

Review of Financial and Operating Results


	For the Fiscal Year Ended September 30
	2025		2024		2023		2025 vs. 2024		2024 vs. 2023
	(In thousands, unless otherwise noted)
Operating revenues	$	4,425,397	$	3,915,141	$	4,099,690	$	510,256	$	(184,549)
Purchased gas cost	1,854,323		1,620,515		2,061,920		233,808		(441,405)

Operating expenses	1,607,684		1,440,192		1,345,144		167,492		95,048
Operating income	963,390		854,434		692,626		108,956		161,808
Other non-operating income	33,578		30,106		24,988		3,472		5,118
Interest charges	99,226		117,086		77,185		(17,860)		39,901
Income before income taxes	897,742		767,454		640,429		130,288		127,025
Income tax expense	150,961		96,041		60,032		54,920		36,009

Net income	$	746,781	$	671,413	$	580,397	$	75,368	$	91,016
Consolidated distribution sales volumes — MMcf	289,065		283,977		289,948		5,088		(5,971)
Consolidated distribution transportation volumes — MMcf	156,859		156,389		152,963		470		3,426
Total consolidated distribution throughput — MMcf	445,924		440,366		442,911		5,558		(2,545)

Consolidated distribution average cost of gas per Mcf sold	$	6.41	$	5.71	$	7.11	$	0.70	$	(1.40)

~~Financial~~Fiscal ~~and~~year ~~operational~~ended ~~highlights~~September 30, ~~for~~2025 ~~our~~compared ~~distribution~~with ~~segment for the~~ fiscal ~~years~~year ended September 30, 2024, ~~2023, and 2022 are presented below.~~

	For the Fiscal Year Ended September 30
	2024		2023		2022		2024 vs. 2023		2023 vs. 2022
	(In thousands, unless otherwise noted)
Operating revenues	$	3,915,141	$	4,099,690	$	4,035,194	$	(184,549)	$	64,496
Purchased gas cost	1,620,515		2,061,920		2,210,302		(441,405)		(148,382)
Operating expenses	1,440,192		1,345,144		1,220,347		95,048		124,797
Operating income	854,434		692,626		604,545		161,808		88,081
Other non-operating income	30,106		24,988		6,946		5,118		18,042
Interest charges	117,086		77,185		49,921		39,901		27,264
Income before income taxes	767,454		640,429		561,570		127,025		78,859
Income tax expense	96,041		60,032		39,593		36,009		20,439
Net income	$	671,413	$	580,397	$	521,977	$	91,016	$	58,420
Consolidated distribution sales volumes — MMcf	283,977		289,948		292,266		(5,971)		(2,318)
Consolidated distribution transportation volumes — MMcf	156,389		152,963		152,709		3,426		254
Total consolidated distribution throughput — MMcf	440,366		442,911		444,975		(2,545)		(2,064)
Consolidated distribution average cost of gas per Mcf sold	$	5.71	$	7.11	$	7.56	$	(1.40)	$	(0.45)

Operating income for our distribution segment increased 12.8 percent. Key drivers for the change in operating income include:

~~Fiscal~~•a ~~year~~$184.1 ~~ended~~million ~~September 30,~~increase ~~2024~~in ~~compared~~rate ~~with~~adjustments, ~~fiscal~~primarily ~~year~~in ~~ended~~our ~~September 30,~~Mid-Tex ~~2023~~ Division.

~~Operating~~•a ~~income~~$26.7 ~~for~~million ~~our~~increase ~~distribution~~related ~~segment~~to ~~increased~~residential ~~23.4~~customer ~~percent.~~growth, ~~Key~~primarily ~~drivers~~in ~~for~~our ~~the~~Mid-Tex ~~change~~Division, inand ~~operating~~increased ~~income~~industrial ~~include:~~load.

•a $~~219~~46.23 million ~~increase~~decrease in ~~rate~~refunds ~~adjustments~~of excess deferred taxes to customers, ~~primarily~~which is substantially offset in ~~our~~income ~~Mid-Tex~~tax ~~Division~~expense.

•a $24.8 million increase related to residential customer growth, primarily in our Mid-Tex Division, and increased industrial load.

•a $10.6 million decrease in bad debt expense, as discussed in Note 6 to the consolidated financial statements.

Partially offset by:

•a $5078.0 million increase in depreciation expense and property taxes associated with increased capital investments.

•a $1932.96 million increase in employee-related costs primarily due to an increase in headcount to support company growth.

•aan $218.76 million increase in ~~property~~system ~~taxes~~monitoring, ~~which~~line islocating, ~~inclusive~~and ofother ~~a $15.7 million decrease~~ compliance-related ~~to the Texas property tax legislation discussed above~~activities.

•a $2617.98 million increase in ~~other~~bad ~~operation~~debt ~~and~~expense ~~maintenance~~due ~~expense,~~to ~~including~~a ~~higher~~regulatory ~~costs~~change ~~associated~~in ~~with~~Mississippi ~~software~~in ~~maintenance,~~the ~~compliance~~first ~~activities,~~quarter ~~training~~of fiscal 2024 which significantly reduced bad debt expense in fiscal 2024, ~~and~~as ~~other~~discussed ~~administrative~~in ~~costs~~Note 6 to the consolidated financial statements.

~~Interest~~Additionally, ~~charges~~our ~~increased~~distribution ~~$39.9~~segment's ~~million~~fiscal ~~primarily~~2025 ~~due~~results towere ~~the~~favorably ~~issuance~~impacted ofby ~~long-term debt during fiscal 2024~~$18.5 ~~The~~million ~~increase~~as ina ~~interest~~result ~~charges is also due to the amortization~~ of ~~the~~ Texas ~~regulatory~~legislation ~~asset~~ that isbecame ~~discussed~~effective induring ~~Note 3 to~~ the ~~consolidated~~third ~~financial~~quarter ~~statements.~~of ~~However,~~fiscal ~~this~~2025 ~~increase~~related ~~is offset by a corresponding increase in revenue resulting in no impact~~ to ~~net~~infrastructure ~~income~~spending.

The fiscal year ended September 30, ~~2023~~2024 compared with fiscal year ended September 30, ~~2022~~2023 for our distribution segment is described in Item 7 "Management's Discussion and Analysis of Financial Condition and Results of Operations" of our Annual Report on Form 10-K for the fiscal year ended September 30, ~~2023~~2024.

The following table shows our operating income by distribution division, in order of total rate base, for the fiscal years ended September 30, ~~2024~~2025, ~~2023~~2024, and ~~2022~~2023. The presentation of our distribution operating income is included for financial reporting purposes and may not be appropriate for ratemaking purposes.

Table of Contents

For the Fiscal Year Ended September 30

2024

2023

2022

2024 vs. 2023

2023 vs. 2022

2025

2024

2023

2025 vs. 2024

2024 vs. 2023

(In thousands)

Mid-Tex

~~464~~532,~~616~~570

~~345~~464,~~545~~616

~~315~~345,~~644~~545

~~119~~67,~~071~~954

29119,~~901~~071

Kentucky/Mid-States

90112,~~601~~894

8790,~~258~~601

8487,~~098~~258

322,~~343~~293

3,~~160~~343

Louisiana

94109,~~362~~268

8094,~~942~~362

7380,~~486~~942

1314,~~420~~906

713,~~456~~420

West Texas

7273,~~929~~138

6272,~~351~~929

5362,~~604~~351

~~10,578~~209

810,~~747~~578

Mississippi

9794,~~512~~654

7897,~~517~~512

6578,~~947~~517

18(2,~~995~~858)

1218,~~570~~995

Colorado-Kansas

4237,~~816~~341

4042,~~674~~816

2640,~~000~~674

2(5,~~142~~475)

142,~~674~~142

Other

(83,~~402)~~525

(28,~~661~~402)

(142,~~234~~661)

(511,~~741)~~927

11(5,~~573~~741)

Total

~~854~~963,~~434~~390

~~692~~854,~~626~~434

~~604~~692,~~545~~626

~~161~~108,~~808~~956

88161,~~081~~808

Pipeline and Storage Segment

Our pipeline and storage segment consists of the pipeline and storage operations of our Atmos Pipeline–Texas Division (APT) and our natural gas transmission operations in Louisiana. APT is one of the largest intrastate pipeline operations in Texas with a heavy concentration in the established natural gas producing areas of central, northern, and eastern Texas, extending into or near the major producing areas of the Barnett Shale, the Texas Gulf Coast, and the Permian Basin of West Texas. APT provides transportation and storage services to our Mid-Tex Division, other third-party local distribution companies, industrial, and electric generation customers, as well as marketers and producers. Over 80 percent of this segment's revenues are derived from these APT services. These revenues are subject to traditional ratemaking governed by the Texas Railroad Commission (RRC). As part of its pipeline operations, APT owns and operates five underground storage facilities in Texas.

Our natural gas transmission operations in Louisiana are comprised of a 21-mile pipeline located in the New Orleans, Louisiana area that is primarily used to aggregate gas supply for our distribution division in Louisiana under a long-term contract and, on a more limited basis, to third parties. The demand fee charged to our Louisiana distribution division for these services is subject to regulatory approval by the Louisiana Public Service Commission. We also manage two asset management plans, which have been approved by applicable state regulatory commissions. Generally, these asset management plans require us to share with our distribution customers a significant portion of the cost savings earned from these arrangements.

Our pipeline and storage segment is impacted by seasonal weather patterns, competitive factors in the energy industry, and economic conditions in our Texas and Louisiana service areas. Natural gas prices do not directly impact the results of this segment as revenues are derived from the transportation and storage of natural gas. However, natural gas prices and demand for natural gas could influence the level of drilling activity in the supply areas that we serve, which may influence the level of throughput we may be able to transport on our pipelines. Further, natural gas price differences between the various hubs that we serve in Texas could influence the volumes of gas transported for shippers through our Texas pipeline system and rates for such transportation.

The results of APT are also significantly impacted by the natural gas requirements of its local distribution company customers. Additionally, its operations may be impacted by the timing of when costs and expenses are incurred and when these costs and expenses are recovered through its tariffs.

APT annually uses GRIP to recover capital costs incurred in the prior calendar year. On February 2726, ~~2024~~2025, APT made a GRIP filing that covered changes in net property, plant and equipment investment from January 1, ~~2023~~2024 through December 31, ~~2023~~2024 with a requested increase in operating income of $8277.42 million. On ~~May~~June 1417, ~~2024~~2025, the Texas Railroad Commission (RRC) approved the Company's GRIP filing.

Additionally, GRIP requires a utility to file a statement of intent at least once every five years to review its costs and expenses, including capital costs filed for recovery under GRIP. On May 19, 2023, APT filed its statement of intent seeking $107.4 million in additional annual operating income. On December 13, 2023, the RRC approved the settlement agreement between APT and the intervening parties for an increase in annual operating income of $27.0 million, exclusive of the impact of the cessation of $36.9 million in excess deferred income tax refunds, which are substantially offset by a corresponding increase in income taxes. New rates were implemented effective December 13, 2023.

The demand fee our Louisiana natural gas transmission pipeline charges to our Louisiana distribution division increases five percent annually and has been approved by the Louisiana Public Service Commission until September 30, 2027.

Review of Financial and Operating Results

Financial and operational highlights for our pipeline and storage segment for the fiscal years ended September 30, ~~2024~~2025, ~~2023~~2024, and ~~2022~~2023 are presented below.

Table of Contents

For the Fiscal Year Ended September 30

2024

2023

2022

2024 vs. 2023

2023 vs. 2022

2025

2024

2023

2025 vs. 2024

2024 vs. 2023

(In thousands, unless otherwise noted)

Mid-Tex / Affiliate transportation revenue

~~715~~815,~~117~~628

~~621~~715,~~987~~117

~~546~~621,~~038~~987

93100,~~130~~511

7593,~~949~~130

Third-party transportation revenue

~~210~~238,~~568~~667

~~154~~210,~~018~~568

~~136~~154,~~907~~018

5628,~~550~~099

1756,~~111~~550

Other revenue

1211,~~344~~005

912,~~169~~344

109,~~715~~169

3(1,~~175~~339)

(13,~~546)~~175

Total operating revenues

~~938~~1,~~029~~065,300

~~785~~938,~~174~~029

~~693~~785,~~660~~174

~~152~~127,~~855~~271

91152,~~514~~855

Total purchased gas cost

~~146~~(1,346)

~~(1,220)~~146

(1,~~583~~220)

(1,~~366~~492)

~~363~~1,366

Operating expenses

~~436~~470,~~955~~065

~~411~~436,~~873~~955

~~378~~411,~~806~~873

2533,~~082~~110

3325,~~067~~082

Operating income

~~500~~596,~~928~~581

~~374~~500,~~521~~928

~~316~~374,~~437~~521

~~126~~95,~~407~~653

58126,~~084~~407

Other non-operating income

4056,~~940~~163

4440,~~787~~940

2644,~~791~~787

(315,~~847)~~223

17(3,~~996~~847)

Interest charges

7372,~~546~~452

6073,~~096~~546

5260,~~890~~096

13(1,~~450~~094)

713,~~206~~450

Income before income taxes

~~468~~580,~~322~~292

~~359~~468,~~212~~322

~~290~~359,~~338~~212

~~109~~111,~~110~~970

68109,~~874~~110

Income tax expense

96128,~~840~~319

5396,~~747~~840

3753,~~917~~747

4331,~~093~~479

1543,~~830~~093

Net income

~~371~~451,~~482~~973

~~305~~371,~~465~~482

~~252~~305,~~421~~465

6680,~~017~~491

5366,~~044~~017

Gross pipeline transportation volumes — MMcf

~~831~~907,~~534~~536

~~834~~831,~~847~~534

~~776~~834,~~608~~847

(376,~~313)~~002

58(3,~~239~~313)

Consolidated pipeline transportation volumes — MMcf

~~635~~709,~~728~~645

635,~~508~~728

~~580~~635,~~488~~508

~~220~~73,917

~~55,020~~220

Fiscal year ended September 30, ~~2024~~2025 compared with fiscal year ended September 30, ~~2023~~2024

Operating income for our pipeline and storage segment increased 3319.81 percent. Key drivers for the change in operating income include:

•aan $6889.4 million increase primarily due to rate adjustments from the GRIP filings approved in May ~~2023~~2024 and June 2025, the System Safety and Integrity Rider filing approved in November 2024, and the rate case approved in December 2023.

•a $397.07 million ~~net~~ increase in APT's through-system activities ~~primarily associated with increased spreads~~.

•a $279.81 million decrease in refunds of excess deferred taxes to customers, which is substantially offset in income tax expense.

•a $1416.5 million increase due to higher capacity contracted by tariff-based customers due to their increased peak day demand.

•a $3.1 million decrease in property taxes, which is inclusive of a $5.4 million decrease related to the Texas property tax legislation discussed above.

Partially offset by:

•ana $823.45 million increase in depreciation expense and property taxes associated with increased capital investments.

•an $18.19 million increase in ~~operation~~expenses ~~and~~recognized ~~maintenance~~as ~~expense~~a ~~due~~result toof ~~increased~~the ~~storage~~System Safety and ~~compression~~Integrity ~~maintenance~~Rider ~~and~~filing ~~other~~approved ~~compliance-related~~in ~~activities~~November 2024, which is offset in operating revenues.

~~Interest~~Other ~~charges~~non-operating income increased $1315.52 million primarily due to ~~the~~higher ~~issuance~~AFUDC largely as a result of ~~long-term~~increased ~~debt~~capital spending. Additionally, our pipeline and storage segment's fiscal 2025 results were favorably impacted by $7.7 million as a result of Texas legislation that became effective during the third quarter of fiscal ~~2024~~2025 related to infrastructure spending.

The fiscal year ended September 30, ~~2023~~2024 compared with fiscal year ended September 30, ~~2022~~2023 for our pipeline and storage segment is described in Item 7 "Management's Discussion and Analysis of Financial Condition and Results of Operations" of our Annual Report on Form 10-K for the fiscal year ended September 30, ~~2023~~2024.

Table of Contents

LIQUIDITY AND CAPITAL RESOURCES

The liquidity required to fund our working capital, capital expenditures, and other cash needs is provided from a combination of internally generated cash flows and external debt and equity financing. Additionally, we have a $1.5 billion commercial paper program and four committed revolving credit facilities with $3.1 billion in total availability from third-party lenders. The commercial paper program and credit facilities provide cost-effective, short-term financing until it can be replaced with a balance of long-term debt and equity financing that achieves the Company's desired capital structure. Additionally, we have various uncommitted trade credit lines with our gas suppliers that we utilize to purchase natural gas on a monthly basis.

We have a shelf registration statement on file with the Securities and Exchange Commission (SEC) that allows us to issue up to $58.0 billion in common stock and/or debt securities. As of the date of this report, $15.12 billion of securities remained available for issuance under the shelf registration statement, which expires ~~March~~December 313, ~~2026~~2027.

We also have an at-the-market (ATM) equity sales program that allows us to issue and sell shares of our common stock up to an aggregate offering price of $1.7 billion (including shares of common stock that may be sold pursuant to forward sale agreements entered into in connection with the ATM equity sales program), which expires December 3, 2027. As of the date of this report, $828.5 million of equity is available for issuance under this ATM equity sales program. Additionally, as of September 30, 2025, we had $1.6 billion in available proceeds from outstanding forward sale agreements issued under the ATM program.

We also have an at-the-market (ATM) equity sales program that allows us to issue and sell shares of our common stock up to an aggregate offering price of $1.0 billion (including shares of common stock that may be sold pursuant to forward sale agreements entered into in connection with the ATM equity sales program), which expires March 31, 2026. As of the date of this report, $10.0 million of equity is available for issuance under this ATM equity sales program. Additionally, as of September 30, 2024, we had $1.4 billion in available proceeds from outstanding forward sale agreements issued under the ATM program.

In the first half of fiscal 2025, we anticipate filing a new $8.0 billion shelf registration statement and a prospectus supplement under this new shelf registration statement for a new $1.7 billion ATM equity sales program to replace the former arrangements.

As of September 30, 2024, we had the following forward starting interest rate swaps in place to hedge future planned debt issuances:

Planned Debt Issuance Date	Amount Hedged		Effective Interest Rate
	(In thousands)
Fiscal 2026	$	300,000	2.16	%
	$	300,000

The liquidity provided by these sources is expected to be sufficient to fund the Company's working capital needs and capital expenditures program. Additionally, we expect to continue to be able to obtain financing upon reasonable terms as necessary.

The following table presents our capitalization as of September 30, ~~2024~~2025 and ~~2023~~2024:

	September 30
	2024				2023
	2025				2024
	(In thousands, except percentages)
Short-term debt	$	—	—	%	$	~~241,933~~—	~~1.4~~—	%
Long-term debt (1)	78,~~785~~918,~~297~~944		39.07	%	67,~~555~~785,~~701~~297		3739.10	%
Shareholders’ equity	1213,~~157~~558,~~669~~890		6160.03	%	1012,~~870~~157,~~064~~669		61.50	%
Total capitalization, including short-term debt	$	1922,~~942~~477,~~966~~834	100.0	%	$	1719,~~667~~942,~~698~~966	100.0	%

(1)Inclusive of our finance leases, but exclusive of AEK's securitized long-term debt.

Cash Flows

Our internally generated funds may change in the future due to a number of factors, some of which we cannot control. These factors include regulatory changes, the price for our services, the demand for such products and services, margin requirements resulting from significant changes in commodity prices, operational risks, and other factors.

Cash flows from operating, investing, and financing activities for the years ended September 30, ~~2024~~2025, ~~2023~~2024, and ~~2022~~2023 are presented below.


	For the Fiscal Year Ended September 30
	2025		2024		2023		2025 vs. 2024		2024 vs. 2023
	(In thousands)
Total cash provided by (used in)
Operating activities	$	2,049,456	$	1,733,746	$	3,459,743	$	315,710	$	(1,725,997)
Investing activities	(3,561,282)		(2,922,769)		(2,795,280)		(638,513)		(127,489)
Financing activities	1,406,773		1,478,631		(696,769)		(71,858)		2,175,400
Change in cash and cash equivalents and restricted cash and cash equivalents	(105,053)		289,608		(32,306)		(394,661)		321,914
Cash and cash equivalents and restricted cash and cash equivalents at beginning of period	308,856		19,248		51,554		289,608		(32,306)
Cash and cash equivalents and restricted cash and cash equivalents at end of period	$	203,803	$	308,856	$	19,248	$	(105,053)	$	289,608

Table of Contents

	For the Fiscal Year Ended September 30
	2024		2023		2022		2024 vs. 2023		2023 vs. 2022
	(In thousands)
Total cash provided by (used in)
Operating activities	$	1,733,746	$	3,459,743	$	977,584	$	(1,725,997)	$	2,482,159
Investing activities	(2,922,769)		(2,795,280)		(2,429,958)		(127,489)		(365,322)
Financing activities	1,478,631		(696,769)		1,387,205		2,175,400		(2,083,974)
Change in cash and cash equivalents and restricted cash and cash equivalents	289,608		(32,306)		(65,169)		321,914		32,863
Cash and cash equivalents and restricted cash and cash equivalents at beginning of period	19,248		51,554		116,723		(32,306)		(65,169)
Cash and cash equivalents and restricted cash and cash equivalents at end of period	$	308,856	$	19,248	$	51,554	$	289,608	$	(32,306)

Cash flows for the fiscal year ended September 30, 2024 compared with fiscal year ended September 30, 2023 is described in Item 7 "Management's Discussion and Analysis of Financial Condition and Results of Operations" of our Annual Report on Form 10-K for the fiscal year ended September 30, 2024.

Cash flows for the fiscal year ended September 30, 2023 compared with fiscal year ended September 30, 2022 is described in Item 7 "Management's Discussion and Analysis of Financial Condition and Results of Operations" of our Annual Report on Form 10-K for the fiscal year ended September 30, 2023.

Cash flows from operating activities

For the fiscal year ended September 30, ~~2024~~2025, cash flow provided by operating activities was $12,~~733~~049.75 million compared with $31,~~459~~733.7 million in the prior year. ~~Fiscal~~The 2023 operating cash flow included $2,021.9 million of cash received as a result of the conclusion of Texas securitization proceedings. Excluding this cash inflow, operating cash flow in fiscal 2023 was $1,437.8 million, and the year-over-year increase in operating cash flow primarily reflects the positive effects of successful rate case outcomes achieved in fiscal ~~2024~~2025 and ~~2023~~2024.

Cash flows from investing activities

Our capital expenditures are primarily used to improve the safety and reliability of our distribution and transmission system through pipeline replacement and system modernization and to enhance and expand our system to meet customer needs. Over the last three fiscal years, approximately 8685 percent of our capital spending has been committed to improving the safety and reliability of our system.

For the fiscal year ended September 30, ~~2024~~2025, we had $23.96 billion in capital expenditures compared with $2.89 billion for the fiscal year ended September 30, ~~2023~~2024. Capital spending in our distribution segment increased $~~322~~413.24 million, primarily as a result of increased system modernization and customer growth spending. Capital spending in our pipeline and storage segment ~~decreased~~increased $~~191~~210.09 million, primarily due to ~~the~~increased ~~timing of~~ spending for pipeline system safety and reliability in Texas.

Cash flows from financing activities

Our financing activities provided $1,~~478~~406.68 million of cash for fiscal year ~~2024~~2025 compared with $~~696~~1,478.86 million of cash ~~used~~provided by financing activities for fiscal year ~~2023~~2024.

During the fiscal year ended September 30, ~~2024~~2025, we received approximately $21.08 billion in net proceeds from the issuance of long-term debt and equity. We completed a public offering of $~~500~~650 million of ~~6.20% senior notes due October 2053 and $400 million of~~ 5.9000% senior notes due ~~October~~December ~~2033~~2054, and received net proceeds from the offering, after the underwriting discount and offering expenses, of $~~889~~639.4 million. We also completed a public offering of $~~325~~500 million of 5.9020% senior notes due ~~October~~August ~~2033~~2035, and received net proceeds from the offering, after the underwriting discount and offering expenses, of $~~339~~493.07 million. Additionally, during the fiscal year ended September 30, ~~2024~~2025, we settled 65,~~401~~931,~~469~~289 shares that had been sold on a forward basis for net proceeds of $~~750~~698.05 million. The net proceeds were used primarily to support capital spending and for other general corporate purposes. We also received $~~231~~122.19 million from the settlement of forward starting interest rate swaps related to a debt issuance completed in October ~~2024~~2025. Cash dividends increased due to an 8.81 percent increase in our dividend rate and an increase in shares outstanding.

During the fiscal year ended September 30, ~~2023~~2024, we ~~repaid $2.2 billion in long-term debt, and we~~ received approximately $12.60 billion in net proceeds from the issuance of long-term debt and equity. We completed a public offering of $500 million of 56.7520% senior notes due ~~October~~November ~~2052~~2053 and $~~300~~400 million of 5.4590% senior notes due ~~October~~November ~~2032~~2033, and received net proceeds from the offering, after the underwriting discount and offering expenses, of $~~789~~889.4 million. We also completed a public offering of $325 million of 5.90% senior notes due November 2033, and received net proceeds from the offering, after the underwriting discount and offering expenses, of $339.0 million. Additionally, during the year ended September 30, ~~2023~~2024, we settled 76,~~272~~401,~~261~~469 shares that had been sold on a forward basis for net proceeds of $~~806~~750.90 million. The net proceeds were used primarily to support capital spending and for other general corporate purposes. We also received $~~171~~231.1 million from the settlement of forward starting interest rate swaps related to a debt issuance completed in October ~~2023~~2024. Cash dividends increased due to an 8.8 percent increase in our dividend rate and an increase in shares outstanding.

The following table shows the number of shares issued for the fiscal years ended September 30, 2025, 2024, and 2023:


	For the Fiscal Year Ended September 30
	2025	2024	2023
Shares issued:
Direct Stock Purchase Plan	47,422	60,756	64,871
Retirement Savings Plan and Trust	54,565	67,134	69,716
1998 Long-Term Incentive Plan (LTIP)	276,263	236,703	189,337

Equity Issuance (1)	5,931,289	6,401,469	7,272,261


Total shares issued	6,309,539	6,766,062	7,596,185

(1)Share amounts do not include shares issued under forward sale agreements until the shares have been settled.

Table of Contents

outstanding. Finally, Atmos Energy Kansas Securitization I, LLC, a special-purpose, wholly-owned subsidiary of Atmos Energy, issued $95 million in securitized long-term debt.

The following table shows the number of shares issued for the fiscal years ended September 30, 2024, 2023, and 2022:

	For the Fiscal Year Ended September 30
	2024	2023	2022
Shares issued:
Direct Stock Purchase Plan	60,756	64,871	68,693
Retirement Savings Plan and Trust	67,134	69,716	72,339
1998 Long-Term Incentive Plan (LTIP)	236,703	189,337	427,929
Equity Issuance (1)	6,401,469	7,272,261	7,907,883
Total shares issued	6,766,062	7,596,185	8,476,844

(1)Share amounts do not include shares issued under forward sale agreements until the shares have been settled.

Credit Ratings

Our credit ratings directly affect our ability to obtain short-term and long-term financing, in addition to the cost of such financing. In determining our credit ratings, the rating agencies consider a number of quantitative factors, including but not limited to, debt to total capitalization, operating cash flow relative to outstanding debt, operating cash flow coverage of interest, and operating cash flow less dividends to debt. In addition, the rating agencies consider qualitative factors such as consistency of our earnings over time, the risks associated with our business, and the regulatory structures that govern our rates in the states where we operate.

Our debt is rated by two rating agencies: Standard & Poor’s Corporation (S&P) and Moody’s Investors Service (Moody’s). On April 12, ~~2024~~2025, Moody's reaffirmed its ~~long~~short-term ~~and~~credit ~~short~~ratings, downgraded our long-term credit ~~ratings~~rating to A2, and placed our ratings under ~~negative~~stable outlook. ~~As of September 30~~Currently, ~~2024,~~ our outlook and current debt ratings, which are all considered investment grade, are as follows:

S&P

Moody’s

Senior unsecured long-term debt

A-

A1A2

Short-term debt

A-2

P-1

Outlook

Stable

~~Negative~~Stable

A significant degradation in our operating performance or a significant reduction in our liquidity caused by more limited access to the private and public credit markets as a result of deteriorating global or national financial and credit conditions could trigger a negative change in our ratings outlook or even a reduction in our credit ratings by the two credit rating agencies. This would mean more limited access to the private and public credit markets and an increase in the costs of such borrowings.

A credit rating is not a recommendation to buy, sell or hold securities. The highest investment grade credit rating is AAA for S&P and Aaa for Moody’s. The lowest investment grade credit rating is BBB- for S&P and Baa3 for Moody’s. Our credit ratings may be revised or withdrawn at any time by the rating agencies, and each rating should be evaluated independently of any other rating. There can be no assurance that a rating will remain in effect for any given period of time or that a rating will not be lowered, or withdrawn entirely, by a rating agency if, in its judgment, circumstances so warrant.

Debt Covenants

We were in compliance with all of our debt covenants as of September 30, ~~2024~~2025. Our debt covenants are described in Note 8 to the consolidated financial statements.

Contractual Obligations and Commercial Commitments

The following table provides information about contractual obligations and commercial commitments at September 30, ~~2024~~2025.


	Payments Due by Period
	Total		Less than 1 year		1-3 years		3-5 years		More than 5 years
					(In thousands)
Contractual Obligations
Long-term debt (1)	$	8,935,000	$	10,000	$	650,000	$	500,000	$	7,775,000

Securitized long-term debt	77,003		8,767		18,647		20,645		28,944
Interest charges (2)	7,867,907		418,219		827,500		779,125		5,843,063
Interest charges on securitized long-term debt	16,841		3,860		6,343		4,345		2,293
Finance leases (3)	63,067		3,502		7,203		7,485		44,877
Operating leases (4)	375,802		56,546		99,453		75,059		144,744


Financial instrument obligations (5)	6,485		6,339		146		—		—
Pension and postretirement benefit plan contributions (6)	286,856		30,175		75,661		45,773		135,247
Uncertain tax positions (7)	60,332		—		60,332		—		—
Total contractual obligations	$	17,689,293	$	537,408	$	1,745,285	$	1,432,432	$	13,974,168

(1)Long-term debt excludes our finance lease obligations, which are separately reported within this table. See Note 8 to the consolidated financial statements for further details.

Table of Contents

	Payments Due by Period
	Total		Less than 1year		1-3 years		3-5 years		More than 5years
					(In thousands)
Contractual Obligations
Long-term debt (1)	$	7,785,000	$	—	$	510,000	$	650,000	$	6,625,000
Securitized long-term debt	85,078		8,207		17,721		19,621		39,529
Interest charges (2)	5,854,623		318,117		635,037		592,054		4,309,415
Interest charges on securitized long-term debt	21,071		4,281		7,255		5,356		4,179
Finance leases (3)	66,506		3,438		7,070		7,338		48,660
Operating leases (4)	320,408		43,244		73,917		56,419		146,828
Financial instrument obligations (5)	7,637		7,324		313		—		—
Pension and postretirement benefit plan contributions (6)	273,428		27,596		51,411		65,310		129,111
Uncertain tax positions (7)	57,797		—		57,797		—		—
Total contractual obligations	$	14,471,548	$	412,207	$	1,360,521	$	1,396,098	$	11,302,722

(1)Long-term debt excludes our finance lease obligations, which are separately reported within this table. See Note 8 to the consolidated financial statements for further details.

(2)Interest charges were calculated using the coupon rate for each debt issuance through the contractual maturity date.

(3)Finance lease payments shown above include interest totaling $1715.68 million. See Note 7 to the consolidated financial statements.

(4)Operating lease payments shown above include interest totaling $6168.62 million. See Note 7 to the consolidated financial statements.

(5)Represents liabilities for natural gas commodity financial instruments that were valued as of September 30, ~~2024~~2025. The ultimate settlement amounts of these remaining liabilities are unknown because they are subject to continuing market risk until the financial instruments are settled.

(6)Represents expected contributions to our defined benefit and postretirement benefit plans, which are discussed in Note 11 to the consolidated financial statements.

(7)Represents liabilities associated with uncertain tax positions claimed or expected to be claimed on tax returns. The amount does not include interest and penalties that may be applied to these positions. See Note 15 to the consolidated financial statements for further details.

We maintain supply contracts with several vendors that generally cover a period of up to one year. Commitments for estimated base gas volumes are established under these contracts on a monthly basis at contractually negotiated prices. Commitments for incremental daily purchases are made as necessary during the month in accordance with the terms of individual contracts. Our Mid-Tex Division also maintains a limited number of long-term supply contracts to ensure a reliable source of gas for our customers in its service area which obligate it to purchase specified volumes at market and fixed prices. At September 30, ~~2024~~2025, we were committed to purchase 2573.94 Bcf within one year and 38114.79 Bcf within two to three years under indexed contracts. At September 30, ~~2024~~2025, we were committed to purchase 621.80 Bcf within one year under fixed price contracts with a weighted average price of $32.1070 per Mcf.

Risk Management Activities

In our distribution and pipeline and storage segments, we use a combination of physical storage, fixed physical contracts, and fixed financial contracts to reduce our exposure to unusually large winter-period gas price increases. Additionally, we manage interest rate risk by entering into financial instruments to effectively fix the Treasury yield component of the interest cost associated with anticipated financings.

We record our financial instruments as a component of risk management assets and liabilities, which are classified as current or noncurrent based upon the anticipated settlement date of the underlying financial instrument. Substantially all of our financial instruments are valued using external market quotes and indices.

The following table shows the components of the change in fair value of our financial instruments for the fiscal year ended September 30, ~~2024~~2025 (in thousands):

Fair value of contracts at September 30, 2023	$	370,256
Fair value of contracts at September 30, 2024	$	88,651
Contracts realized/settled	(~~264~~130,~~650~~755)
Fair value of new contracts	45,~~790~~181
Other changes in value	~~(21~~40,~~745)~~335
Fair value of contracts at September 30, 2024	88,651
Fair value of contracts at September 30, 2025	3,412
Netting of cash collateral	—
Cash collateral and fair value of contracts at September 30, 2024	$	88,651
Cash collateral and fair value of contracts at September 30, 2025	$	3,412

34The fair value of our financial instruments at September 30, 2025, is presented below by time period and fair value source:

Table of Contents


	Fair Value of Contracts at September 30, 2025
	Maturity in years
Source of Fair Value	Less than 1		1-3		4-5		Greater than 5		Total Fair Value
	(In thousands)
Prices actively quoted	$	(1,036)	$	4,448	$	—	$	—	$	3,412
Prices based on models and other valuation methods	—		—		—		—		—
Total Fair Value	$	(1,036)	$	4,448	$	—	$	—	$	3,412

The fair value of our financial instruments at September 30, 2024, is presented below by time period and fair value source:

	Fair Value of Contracts at September 30, 2024
	Maturity in years
Source of Fair Value	Lessthan 1		1-3		4-5		Greaterthan 5		TotalFairValue
	(In thousands)
Prices actively quoted	$	(5,233)	$	93,884	$	—	$	—	$	88,651
Prices based on models and other valuation methods	—		—		—		—		—
Total Fair Value	$	(5,233)	$	93,884	$	—	$	—	$	88,651

RECENT ACCOUNTING DEVELOPMENTS

Recent accounting developments and their impact on our financial position, results of operations and cash flows are described in Note 2 to the consolidated financial statements.


ITEM 7A.			Quantitative and Qualitative Disclosures About Market Risk.

Table of Contents

We are exposed to risks associated with commodity prices and interest rates. Commodity price risk is the potential loss that we may incur as a result of changes in the fair value of a particular instrument or commodity. Interest-rate risk is the potential increased cost we could incur when we issue debt instruments or to provide financing and liquidity for our business activities. Additionally, interest-rate risk could affect our ability to issue cost effective equity instruments.

We conduct risk management activities in our distribution and pipeline and storage segments. In our distribution segment, we use a combination of physical storage, fixed-price forward contracts, and financial instruments, primarily over-the-counter swap and option contracts, in an effort to minimize the impact of natural gas price volatility on our customers during the winter heating season. Our risk management activities and related accounting treatment are described in further detail in Note 16 to the consolidated financial statements. Additionally, our earnings are affected by changes in short-term interest rates as a result of our issuance of short-term commercial paper and our other short-term borrowings.

Commodity Price Risk

We purchase natural gas for our distribution operations. Substantially all of the costs of gas purchased for distribution operations are recovered from our customers through purchased gas cost adjustment mechanisms. Therefore, our distribution operations have limited commodity price risk exposure.

Interest Rate Risk

Our earnings are exposed to changes in short-term interest rates associated with our short-term commercial paper program and other short-term borrowings. We use a sensitivity analysis to estimate our short-term interest rate risk. For purposes of this analysis, we estimate our short-term interest rate risk as the difference between our actual interest expense for the period and estimated interest expense for the period assuming a hypothetical average one percent increase in the interest rates associated with our short-term borrowings. Had interest rates associated with our short-term borrowings increased by an average of one percent, our interest expense would not have materially increased during ~~2024~~2025.

Table of Contents


ITEM 8.			Financial Statements and Supplementary Data.

Index to financial statements and financial statement schedules:

			Page
Report of independent registered public accounting firm (PCAOB ID: 42)			37
Financial statements and supplementary data:
Consolidated balance sheets at September 30, 2024 and 2023			39
Consolidated balance sheets at September 30, 2025 and 2024			39
Consolidated statements of comprehensive income for the years ended September 30, 2024, 2023, and 2022			40
Consolidated statements of comprehensive income for the years ended September 30, 2025, 2024, and 2023			40
Consolidated statements of shareholders' equity for the years ended September 30, 2024, 2023, and 2022			41
Consolidated statements of shareholders' equity for the years ended September 30, 2025, 2024, and 2023			41
Consolidated statements of cash flows for the years ended September 30, 2024, 2023, and 2022			42
Consolidated statements of cash flows for the years ended September 30, 2025, 2024, and 2023			42
Notes to consolidated financial statements			44

All financial statement schedules are omitted because the required information is not present, or not present in amounts sufficient to require submission of the schedule or because the information required is included in the financial statements and accompanying notes thereto.

Table of Contents

REPORT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

To the Shareholders and the Board of Directors of Atmos Energy Corporation

Opinion on the Financial Statements

We have audited the accompanying consolidated balance sheets of Atmos Energy Corporation (the Company) as of September 30, ~~2024~~2025 and ~~2023~~2024, the related consolidated statements of comprehensive income, shareholders’ equity and cash flows for each of the three years in the period ended September 30, ~~2024~~2025, and the related notes (collectively referred to as the "consolidated financial statements"). In our opinion, the consolidated financial statements present fairly, in all material respects, the financial position of the Company at September 30, ~~2024~~2025 and ~~2023~~2024, and the results of its operations and its cash flows for each of the three years in the period ended September 30, ~~2024~~2025, in conformity with U.S. generally accepted accounting principles.

We also have audited, in accordance with the standards of the Public Company Accounting Oversight Board (United States) (PCAOB), the Company’s internal control over financial reporting as of September 30, ~~2024~~2025, based on criteria established in Internal Control — Integrated Framework issued by the Committee of Sponsoring Organizations of the Treadway Commission (2013 framework), and our report dated November 1814, ~~2024~~2025 expressed an unqualified opinion thereon.

Basis for Opinion

These financial statements are the responsibility of the Company’s management. Our responsibility is to express an opinion on the Company’s financial statements based on our audits. We are a public accounting firm registered with the PCAOB and are required to be independent with respect to the Company in accordance with the U.S. federal securities laws and the applicable rules and regulations of the Securities and Exchange Commission and the PCAOB.

We conducted our audits in accordance with the standards of the PCAOB. Those standards require that we plan and perform the audit to obtain reasonable assurance about whether the financial statements are free of material misstatement, whether due to error or fraud. Our audits included performing procedures to assess the risks of material misstatement of the financial statements, whether due to error or fraud, and performing procedures that respond to those risks. Such procedures included examining, on a test basis, evidence regarding the amounts and disclosures in the financial statements. Our audits also included evaluating the accounting principles used and significant estimates made by management, as well as evaluating the overall presentation of the financial statements. We believe that our audits provide a reasonable basis for our opinion.

Critical Audit Matter

The critical audit matter communicated below is a matter arising from the current period audit of the financial statements that was communicated or required to be communicated to the audit committee and that: (1) relates to accounts or disclosures that are material to the financial statements and (2) involved our especially challenging, subjective or complex judgments. The communication of the critical audit matter does not alter in any way our opinion on the consolidated financial statements, taken as a whole, and we are not, by communicating the critical audit matter below, providing a separate opinion on the critical audit matter or on the accounts or disclosures to which it relates.

Table of Contents

Regulation Description of the Matter As discussed in Note 3 to the consolidated financial statements, the Company’s distribution and pipeline and storage operations are subject to regulation with respect to rates, service, maintenance of accounting records and various other matters by the respective regulatory authorities in the states in which they operate. The Company’s accounting policies recognize the financial effects of the ratemaking and accounting practices and policies of the various regulatory commissions and are subject to accounting principles for rate-regulated activities. As a result, certain costs are permitted to be capitalized rather than expensed because they can be recovered through rates. The Company records certain costs as regulatory assets when future recovery through customer rates is considered probable. Regulatory liabilities are recorded when it is probable that revenues will be reduced for amounts that will be credited to customers through the ratemaking process. The amounts to be recovered or recognized are based upon the Company’s historical experience and understanding of the regulations. As of September 30, ~~2024~~2025, there were $~~579~~608.47 million of deferred costs included in regulatory assets and $1,~~227~~269.96 million of regulatory liabilities awaiting cash outflow or potential refund.Auditing the effects of regulatory matters is complex as it requires specialized knowledge of rate-regulated activities and assessments as to matters that could affect the recording or updating of regulatory assets and liabilities.


How We Addressed the Matter in Our Audit			We obtained an understanding, evaluated the design, and tested the operating effectiveness of internal controls over the Company's accounting for regulatory assets and liabilities, including, among others, controls over management's assessment of the likelihood of approval by regulators for new matters and controls over the evaluation on rulings with regulatory bodies on existing regulatory assets and liabilities, including factors that may affect the timing or nature of recoverability. We performed audit procedures that included, among others, examining evidence of correspondence with regulatory bodies to test that the Company appropriately evaluated information obtained from regulatory rulings. For example, we assessed the recoverability and completeness of various regulatory assets and liabilities, considering information obtained from regulatory rulings. In addition, we tested that amortization of regulatory assets and liabilities corresponded to relevant regulatory rulings.

/s/ Ernst & Young LLP

We have served as the Company’s auditor since 1983.

Dallas, Texas

November 1814, ~~2024~~2025

Table of Contents

ATMOS ENERGY CORPORATION

CONSOLIDATED BALANCE SHEETS

	September 30
	2024		2023
	2025		2024
	(In thousands,except share data)
ASSETS
Property, plant and equipment	$	2428,~~784~~028,~~285~~820	$	2124,~~958~~784,~~447~~285
Construction in progress	1,~~063~~235,~~798~~316		~~939~~1,~~927~~063,798
	25,848,083		22,898,374
	29,264,136		25,848,083
Less accumulated depreciation and amortization	3,~~643~~971,~~716~~146		3,~~291~~643,~~791~~716
Net property, plant and equipment	2225,~~204~~292,~~367~~990		1922,~~606~~204,~~583~~367
Current assets
Cash and cash equivalents	~~307~~202,~~340~~687		15307,~~404~~340
Restricted cash and cash equivalents (See Note 10)	1,516		3,844
Restricted cash and cash equivalents	1,116		1,516
Cash and cash equivalents and restricted cash and cash equivalents	~~308~~203,~~856~~803		19308,~~248~~856
Accounts receivable, less allowance for uncollectible accounts of $37,056 in 2024 and $40,840 in 2023	365,882		328,654
Accounts receivable, less allowance for uncollectible accounts of $45,259 in 2025 and $37,056 in 2024	375,509		365,882
Gas stored underground	~~169~~171,~~508~~756		~~245~~169,~~830~~508
Other current assets	~~288~~301,~~068~~627		~~292~~288,~~036~~068
Total current assets	1,~~132~~052,~~314~~695		~~885~~1,~~768~~132,314
Securitized intangible asset, less accumulated amortization of $10,756 in 2024 and $1,398 in 2023 (See Note 10)	82,844		92,202
Securitized intangible asset, less accumulated amortization of $18,473 in 2025 and $10,756 in 2024 (See Note 10)	75,127		82,844
Goodwill	731,257		731,257
Deferred charges and other assets	1,~~043~~097,~~683~~453		1,~~201~~043,~~158~~683
	$	2528,~~194~~249,~~465~~522	$	2225,~~516~~194,~~968~~465
CAPITALIZATION AND LIABILITIES
Shareholders’ equity
Common stock, no par value (stated at $0.005 per share); 200,000,000 shares authorized; issued and outstanding: 2024 — 155,258,845 shares; 2023 — 148,492,783 shares	$	776	$	742
Common stock, no par value (stated at $0.005 per share); 200,000,000 shares authorized; issued and outstanding: 2025 — 161,568,384 shares; 2024 — 155,258,845 shares	$	808	$	776
Additional paid-in capital	78,~~474~~221,~~559~~455		67,~~684~~474,~~120~~559
Accumulated other comprehensive income	~~465~~475,~~715~~015		~~518~~465,~~528~~715
Retained earnings	4,~~216~~861,~~619~~612		34,~~666~~216,~~674~~619
Shareholders’ equity	1213,~~157~~558,~~669~~890		1012,~~870~~157,~~064~~669
Long-term debt	78,~~783~~907,~~646~~169		67,~~554~~783,~~133~~646
Securitized long-term debt (See Note 10)	7668,~~871~~236		8576,~~078~~871
Total capitalization	2022,~~018~~534,~~186~~295		1720,~~509~~018,~~275~~186
Commitments and contingencies (See Note 14)
Current liabilities
Accounts payable and accrued liabilities	~~445~~506,~~397~~516		~~336~~445,~~083~~397
Other current liabilities	~~750~~835,~~620~~557		~~763~~750,~~086~~620
Short-term debt	—		241,933
Current maturities of long-term debt	11,775		1,651
Current maturities of long-term debt	1,651		1,568
Current maturities of securitized long-term debt (See Note 10)	8,767		8,207
Current maturities of securitized long-term debt (See Note 10)	8,207		9,922
Total current liabilities	1,362,615		1,205,875
Total current liabilities	1,205,875		1,352,592
Deferred income taxes	2,918,347		2,593,342
Deferred income taxes	2,593,342		2,304,974
Regulatory excess deferred taxes (See Note 15)	117,482		177,315
Regulatory excess deferred taxes (See Note 15)	177,315		253,212
Regulatory cost of removal obligation	532,461		507,815
Regulatory cost of removal obligation	507,815		497,017
Deferred credits and other liabilities	784,322		691,932
Deferred credits and other liabilities	691,932		599,898
	$	28,249,522	$	25,194,465
	$	25,194,465	$	22,516,968

See accompanying notes to consolidated financial statements.

Table of Contents

ATMOS ENERGY CORPORATION

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME

Year Ended September 30

2024

2023

2022

2025

2024

2023

(In thousands, except per share data)

Operating revenues

Distribution segment

34,~~915~~425,~~141~~397

43,~~099~~915,~~690~~141

4,~~035~~099,~~194~~690

Pipeline and storage segment

~~938~~1,~~029~~065,300

~~785~~938,~~174~~029

~~693~~785,~~660~~174

Intersegment eliminations

(~~687~~787,~~983~~942)

(~~609~~687,~~507~~983)

(~~527~~609,~~192~~507)

Total operating revenues

4,~~165~~702,~~187~~755

4,~~275~~165,~~357~~187

4,~~201~~275,~~662~~357

Purchased gas cost

Distribution segment

1,~~620~~854,~~515~~323

21,~~061~~620,~~920~~515

2,~~210~~061,~~302~~920

Pipeline and storage segment

~~146~~(1,346)

~~(1,220)~~146

(1,~~583~~220)

Intersegment eliminations

(~~686~~786,~~968~~923)

(~~608~~686,~~527~~968)

(~~526~~608,~~063~~527)

Total purchased gas cost

~~933~~1,~~693~~066,054

1933,~~452,173~~693

1,~~682~~452,~~656~~173

Operation and maintenance expense

~~819~~902,~~137~~942

~~764~~819,~~906~~137

~~710~~764,~~161~~906

Depreciation and amortization expense

~~669~~734,~~972~~745

~~604~~669,~~327~~972

~~535~~604,~~655~~327

Taxes, other than income

~~387~~439,~~023~~043

~~386~~387,~~804~~023

~~352~~386,~~208~~804

Operating income

1,~~355~~559,~~362~~971

1,~~067~~355,~~147~~362

~~920~~1,~~982~~067,147

Other non-operating income

7189,~~046~~741

6971,~~775~~046

3369,~~737~~775

Interest charges

~~190~~171,~~632~~678

~~137~~190,~~281~~632

~~102~~137,~~811~~281

Income before income taxes

1,~~235~~478,~~776~~034

~~999~~1,~~641~~235,776

~~851~~999,~~908~~641

Income tax expense

~~192~~279,~~881~~280

~~113~~192,~~779~~881

77113,~~510~~779

Net income

1,~~042~~198,~~895~~754

~~885~~1,~~862~~042,895

~~774~~885,~~398~~862

Basic net income per share

67.8354

6.1083

56.6110

Diluted net income per share

67.8346

6.1083

56.6010

Weighted average shares outstanding:

Basic

~~152~~158,~~508~~943

~~145~~152,~~121~~508

~~137~~145,~~830~~121

Diluted

~~152~~160,~~666~~573

~~145~~152,~~166~~666

~~138~~145,~~096~~166

Net income

1,~~042~~198,~~895~~754

~~885~~1,~~862~~042,895

~~774~~885,~~398~~862

Other comprehensive income (loss), net of tax

Net unrealized holding gains (losses) on available-for-sale securities, net of tax of $168, $37 and $(157)

582

126

(542)

Net unrealized holding gains (losses) on available-for-sale securities, net of tax of $(3), $168 and $37

(4)

582

126

Cash flow hedges:

Amortization and unrealized gains (losses) on interest rate agreements, net of tax of $(15,432), $43,148 and $86,664

(53,395)

149,290

299,851

Amortization and unrealized gains (losses) on interest rate agreements, net of tax of $1,103, $(15,432) and $43,148

9,304

(53,395)

149,290

Total other comprehensive income (loss)

~~(52~~9,~~813)~~300

~~149~~(52,~~416~~813)

~~299~~149,~~309~~416

Total comprehensive income

~~990~~1,~~082~~208,054

1990,~~035,278~~082

1,~~073~~035,~~707~~278

See accompanying notes to consolidated financial statements.

Table of Contents

ATMOS ENERGY CORPORATION

CONSOLIDATED STATEMENTS OF SHAREHOLDERS’ EQUITY

	Common stock			AdditionalPaid-inCapital		AccumulatedOtherComprehensive Income(Loss)		RetainedEarnings		Total
	Number ofShares	StatedValue
	(In thousands, except share and per share data)
Balance, September 30, 2021	132,419,754	$	662	$	5,023,751	$	69,803	$	2,812,673	$	7,906,889
Balance, September 30, 2022	140,896,598	$	704	$	5,838,118	$	369,112	$	3,211,157	$	9,419,091
Net income	—	—		—		—		774,398		774,398
Other comprehensive income	—	—		—		299,309		—		299,309
Cash dividends ($2.72 per share)	—	—		—		—		(375,914)		(375,914)
Common stock issued:
Public offering	7,907,883	40		776,765		—		—		776,805
Direct stock purchase plan	68,693	—		7,495		—		—		7,495
Retirement savings plan	72,339	—		7,908		—		—		7,908
1998 Long-term incentive plan	427,929	2		2,396		—		—		2,398
Employee stock-based compensation	—	—		19,803		—		—		19,803
Balance, September 30, 2022	140,896,598	704		5,838,118		369,112		3,211,157		9,419,091
Net income	—	—		—		—		885,862		885,862
Other comprehensive income	—	—		—		149,416		—		149,416
Cash dividends ($2.96 per share)	—	—		—		—		(430,345)		(430,345)
Common stock issued:
Public offering	7,272,261	36		806,913		—		—		806,949
Direct stock purchase plan	64,871	—		7,429		—		—		7,429
Retirement savings plan	69,716	1		7,965		—		—		7,966
1998 Long-term incentive plan	189,337	1		2,107		—		—		2,108
Employee stock-based compensation	—	—		21,588		—		—		21,588
Balance, September 30, 2023	148,492,783	742		6,684,120		518,528		3,666,674		10,870,064
Net income	—	—		—		—		1,042,895		1,042,895
Other comprehensive loss	—	—		—		(52,813)		—		(52,813)
Cash dividends ($3.22 per share)	—	—		—		—		(492,950)		(492,950)
Common stock issued:
Public offering	6,401,469	32		749,955		—		—		749,987
Direct stock purchase plan	60,756	—		7,129		—		—		7,129
Retirement savings plan	67,134	1		7,954		—		—		7,955
1998 Long-term incentive plan	236,703	1		2,197		—		—		2,198
Employee stock-based compensation	—	—		23,204		—		—		23,204
Balance, September 30, 2024	155,258,845	$776	~~776~~	$7,474,559	~~7,474,559~~	$465,715	~~465,715~~	$4,216,619	~~4,216,619~~	$12,157,669	~~12,157,669~~
Net income	—	—		—		—		1,198,754		1,198,754
Other comprehensive income	—	—		—		9,300		—		9,300
Cash dividends ($3.48 per share)	—	—		—		—		(553,761)		(553,761)
Common stock issued:
Public offering	5,931,289	30		698,432		—		—		698,462
Direct stock purchase plan	47,422	—		7,231		—		—		7,231
Retirement savings plan	54,565	—		8,046		—		—		8,046
1998 Long-term incentive plan	276,263	2		2,683		—		—		2,685
Employee stock-based compensation	—	—		30,504		—		—		30,504
Balance, September 30, 2025	161,568,384	$	808	$	8,221,455	$	475,015	$	4,861,612	$	13,558,890

See accompanying notes to consolidated financial statements.

Table of Contents

ATMOS ENERGY CORPORATION

CONSOLIDATED STATEMENTS OF CASH FLOWS

Year Ended September 30

2024

2023

2022

2025

2024

2023

(In thousands)

CASH FLOWS FROM OPERATING ACTIVITIES

Net income

1,~~042~~198,~~895~~754

~~885~~1,~~862~~042,895

~~774~~885,~~398~~862

Adjustments to reconcile net income to net cash provided by operating activities:

Depreciation and amortization

~~669~~734,~~972~~745

~~604~~669,~~327~~972

~~535~~604,~~655~~327

Deferred income taxes

~~172~~268,~~707~~606

~~108~~172,~~215~~707

53108,~~651~~215

Stock-based compensation

1012,~~709~~731

10,~~178~~709

10,~~743~~178

Amortization of debt issuance costs

(614,~~882~~962)

3(6,~~639~~882)

93,~~141~~639

Equity component of AFUDC

(5875,~~234~~425)

(6458,~~019~~234)

(4564,~~505~~019)

Other

111,~~546~~003

~~(591)~~1,546

~~3,265~~(591)

Changes in assets and liabilities:

(Increase) decrease in accounts receivable

(401,~~909~~417)

46(40,~~859~~909)

~~(34~~46,~~325)~~859

(Increase) decrease in gas stored underground

76(2,~~322~~248)

~~112~~76,~~111~~322

~~(179~~112,~~825)~~111

Decrease in Winter Storm Uri current regulatory asset (see Note 3)

—

2,021,889

—

Decrease in Winter Storm Uri current regulatory asset (see Note 10)

—

2,021,889

(Increase) decrease in other current assets

1719,~~138~~517

~~(36~~17,~~041)~~138

(6536,~~979~~041)

(Increase) decrease in deferred charges and other assets

(195,369)

(172,586)

13,287

Increase in deferred charges and other assets

(211,286)

(195,369)

(172,586)

Increase (decrease) in accounts payable and accrued liabilities

(431,~~563)~~558

(~~132~~4,~~575~~563)

40(132,~~394~~575)

Increase (decrease) in other current liabilities

~~(10~~31,~~287)~~406

30(10,~~687~~287)

~~(152~~30,~~274)~~687

Increase in deferred credits and other liabilities

5846,~~701~~474

4158,~~788~~701

1441,~~958~~788

Net cash provided by operating activities

12,~~733~~049,~~746~~456

31,~~459~~733,~~743~~746

~~977~~3,~~584~~459,743

CASH FLOWS USED IN INVESTING ACTIVITIES

Capital expenditures

(23,~~937~~561,~~124~~399)

(2,~~805~~937,~~973~~124)

(2,~~444~~805,~~420~~973)

Purchases of debt and equity securities

(1934,~~734~~323)

(4619,~~789~~734)

(2846,~~285~~789)

Proceeds from sale of debt and equity securities

57,~~977~~267

255,~~134~~977

425,~~872~~134

Maturities of debt securities

1222,~~050~~801

1312,~~340~~050

2713,~~586~~340

Other, net

164,~~062~~372

1916,~~008~~062

1019,~~289~~008

Net cash used in investing activities

(23,~~922~~561,~~769~~282)

(2,~~795~~922,~~280~~769)

(2,~~429~~795,~~958~~280)

See accompanying notes to consolidated financial statements.

Table of Contents

ATMOS ENERGY CORPORATION

CONSOLIDATED STATEMENTS OF CASH FLOWS

(continued)

Year Ended September 30

2024

2023

2022

2025

2024

2023

(In thousands)

CASH FLOWS FROM FINANCING ACTIVITIES

Net increase (decrease) in short-term debt

~~(241,933)~~—

56(241,~~966~~933)

~~184~~56,~~967~~966

Proceeds from issuance of long-term debt, net of premium/discount

1,~~240~~143,~~204~~447

~~797~~1,~~258~~240,204

~~798~~797,~~802~~258

Proceeds from issuance of securitized long-term debt by AEK

—

~~95,000~~—

—95,000

Net proceeds from equity offering

~~749~~698,~~987~~462

~~806~~749,~~949~~987

~~776~~806,~~805~~949

Issuance of common stock through stock purchase and employee retirement plans

15,~~084~~277

15,~~395~~084

15,~~403~~395

Settlement of interest rate swaps

~~231~~122,~~138~~874

~~171~~231,~~145~~138

~~197~~171,~~073~~145

Proceeds from term loan

—

~~2,020,000~~—

—2,020,000

Repayment of term loan

—

~~(2,020,000)~~—

—(2,020,000)

Repayment of long-term debt

—

~~(2,200,000)~~—

(2,200,000)

Repayment of securitized long-term debt by AEK

(98,~~922~~075)

—(9,922)

—

Cash dividends paid

(~~492~~553,~~950~~761)

(~~430~~492,~~345~~950)

(~~375~~430,~~914~~345)

Debt issuance costs

(1110,~~844~~384)

(711,~~864~~844)

(87,~~196~~864)

Securitized debt issuance costs

—

~~(1,273)~~—

—(1,273)

Other

(1,~~133~~067)

—(1,133)

~~(1,735)~~—

Net cash provided by (used in) financing activities

1,~~478~~406,~~631~~773

~~(696~~1,~~769)~~478,631

1(696,~~387,205~~769)

Net increase (decrease) in cash and cash equivalents and restricted cash and cash equivalents

~~289~~(105,~~608~~053)

~~(32~~289,~~306)~~608

(6532,~~169~~306)

Cash and cash equivalents and restricted cash and cash equivalents at beginning of year

19308,~~248~~856

5119,~~554~~248

~~116~~51,~~723~~554

Cash and cash equivalents and restricted cash and cash equivalents at end of year

~~308~~203,~~856~~803

19308,~~248~~856

5119,~~554~~248

See accompanying notes to consolidated financial statements.

Table of Contents

ATMOS ENERGY CORPORATION

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS

1. Nature of Business

Atmos Energy Corporation (Atmos Energy or the “Company”) and its subsidiaries are engaged in the regulated natural gas distribution and pipeline and storage businesses. Through our distribution business, we deliver natural gas through sales and transportation arrangements to ~~over~~approximately 3.34 million residential, commercial, public-authority, and industrial customers through our six regulated distribution divisions in the service areas described below:


Division						Service Area
Atmos Energy Colorado-Kansas Division						Colorado, Kansas
Atmos Energy Kentucky/Mid-States Division						Kentucky, Tennessee, Virginia
Atmos Energy Louisiana Division						Louisiana
Atmos Energy Mid-Tex Division						Texas, including the Dallas/Fort Worth metropolitan area
Atmos Energy Mississippi Division						Mississippi
Atmos Energy West Texas Division						West Texas

In addition, we transport natural gas for others through our distribution system. Our distribution business is subject to federal and state regulation and/or regulation by local authorities in each of the states in which our distribution divisions operate. Our corporate headquarters and shared-services function are located in Dallas, Texas, and our customer support centers are located in Amarillo and Waco, Texas.

Our pipeline and storage business, which is also subject to federal and state regulation, consists of the pipeline and storage operations of our Atmos Pipeline–Texas (APT) Division and our natural gas transmission business in Louisiana. The APT division provides transportation and storage services to our Mid-Tex Division, other third-party local distribution companies, industrial, and electric generation customers, as well as marketers and producers. As part of its pipeline operations, APT manages five underground storage facilities in Texas. We also provide ancillary services customary to the pipeline industry including parking arrangements, lending, and sales of inventory on hand. Our natural gas transmission operations in Louisiana are comprised of a 21-mile pipeline located in the New Orleans, Louisiana area that is primarily used to aggregate gas supply for our distribution division in Louisiana under a long-term contract and on a more limited basis, to third parties.

2. Summary of Significant Accounting Policies

Principles of consolidation — The accompanying consolidated financial statements include the accounts of Atmos Energy Corporation and its wholly-owned subsidiaries. All material intercompany transactions have been eliminated; however, we have not eliminated intercompany profits when such amounts are probable of recovery under the affiliates’ rate regulation process.

Reclassification — Certain reclassifications have been made to prior period amounts to conform to current period presentation.

Use of estimates — The preparation of financial statements in conformity with accounting principles generally accepted in the United States requires management to make estimates and assumptions that affect the reported amounts of assets, liabilities, revenues, and expenses. The most significant estimates include the allowance for doubtful accounts, unbilled revenues, contingency accruals, pension and postretirement obligations, deferred income taxes, risk management and trading activities, and fair value measurements. Actual results could differ from those estimates.

Regulation — Our distribution and pipeline and storage operations are subject to regulation with respect to rates, service, maintenance of accounting records, and various other matters by the respective regulatory authorities in the states in which we operate. Our accounting policies recognize the financial effects of the ratemaking and accounting practices and policies of the various regulatory commissions. Accounting principles generally accepted in the United States require cost-based, rate-regulated entities that meet certain criteria to reflect the authorized recovery of costs due to regulatory decisions in their financial statements. As a result, certain costs are permitted to be capitalized rather than expensed because they can be recovered through rates. We record certain costs as regulatory assets when future recovery through customer rates is considered probable. Regulatory liabilities are recorded when it is probable that revenues will be reduced for amounts that will be credited to customers through the ratemaking process. The amounts to be recovered or recognized are based upon historical experience and our understanding of the regulations. Further, regulation may impact the period in which revenues or expenses are recognized.

Table of Contents

ATMOS ENERGY CORPORATION

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS — (Continued)

Revenue recognition

Distribution Revenues

Distribution revenues represent the delivery of natural gas to residential, commercial, industrial, and public authority customers at prices based on tariff rates established by regulatory authorities in the states in which we operate. Revenue is recognized and our performance obligation is satisfied over time when natural gas is delivered and simultaneously consumed by our customers. We have elected to use the invoice practical expedient and recognize revenue for volumes delivered that we have the right to invoice our customers. We bill our customers on a monthly cycle basis. Accordingly, we estimate volumes from the last meter read to the balance sheet date and accrue revenue for gas delivered but not yet billed.

In our Texas and Mississippi jurisdictions, we pay franchise fees and gross receipt taxes to operate in these service areas. These franchise fees and gross receipts taxes are required to be paid regardless of our ability to collect from our customers. Accordingly, we account for these amounts on a gross basis in revenue and we record the associated tax expense as a component of taxes, other than income.

Pipeline and Storage Revenues

Pipeline and storage revenues primarily represent the transportation and storage of natural gas on our APT system and the transmission of natural gas through our 21-mile pipeline in Louisiana. APT provides transportation and storage services to our Mid-Tex Division, other third party local distribution companies, and certain industrial customers under tariff rates approved by the RRC. APT also provides certain transportation and storage services to industrial and electric generation customers, as well as marketers and producers, under negotiated rates. Our pipeline in Louisiana is primarily used to aggregate gas supply for our Louisiana Division under a long-term contract and on a more limited basis to third parties. The demand fee charged to our Louisiana Division is subject to regulatory approval by the Louisiana Public Service Commission. We also manage two asset management plans with distribution affiliates of the Company at terms that have been approved by the applicable state regulatory commissions. The performance obligations for these transportation customers are satisfied by means of transporting customer-supplied gas to the designated location. Revenue is recognized and our performance obligation is satisfied over time when natural gas is delivered to the customer. Management determined that these arrangements qualify for the invoice practical expedient for recognizing revenue. For demand fee arrangements, revenue is recognized and our performance obligation is satisfied by standing ready to transport natural gas over the period of each individual month.

Alternative Revenue Program Revenues

In our distribution segment, we have weather-normalization adjustment mechanisms that serve to minimize the effects of weather on our residential and commercial revenues. APT has a regulatory mechanism that requires that we share with its tariffed customers 75% of the difference between the total non-tariffed revenues earned during a test period and a revenue benchmark established by the RRC. With the completion of APT's most recent rate case in December 2023, the revenue benchmark was increased from $69.4 million to $106.9 million. Differences between actual revenues and revenues calculated under these mechanisms adjust the amount billed to customers. These mechanisms are considered to be alternative revenue programs under accounting standards generally accepted in the United States as they are deemed to be contracts between us and our regulator. Accordingly, revenue under these mechanisms are excluded from revenue from contracts with customers.

Purchased gas costs — Rates established by regulatory authorities are adjusted for increases and decreases in our purchased gas costs through purchased gas cost adjustment mechanisms. There is no margin generated through purchased gas cost adjustments, but they provide a dollar-for-dollar offset to increases or decreases in our distribution segment’s gas costs. The effects of these purchased gas cost adjustment mechanisms are recorded as deferred gas costs on our consolidated balance sheets.

Cash and cash equivalents — We consider all highly liquid investments with an original maturity of three months or less to be cash equivalents.

Restricted cash and cash equivalents — Restricted cash and cash equivalents consists of funds that are contractually or legally restricted as to usage or withdrawal and have been presented separately from cash and cash equivalents on our consolidated balance sheets. These funds are used to administer payment of debt service on the Securitized Utility Tariff Bonds as well as certain ongoing costs of Atmos Energy Kansas Securitization I, LLC (AEK).

Accounts receivable and allowance for uncollectible accounts — Accounts receivable arise from natural gas sales to residential, commercial, industrial, public authority, and other customers. Our accounts receivable balance includes unbilled amounts which represent a customer’s consumption of gas from the date of the last cycle billing through the last day of the month. The receivable balances are short term and generally do not extend beyond one month.

Table of Contents

ATMOS ENERGY CORPORATION

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS — (Continued)

Credit losses on our accounts receivable are measured using an expected credit loss model over the entire contractual term from the date of initial recognition. To minimize credit risk, we assess the credit worthiness of new customers, require deposits where necessary, assess late fees, pursue collection activities, and disconnect service for nonpayment. After disconnection, accounts are written off when deemed uncollectible. At each reporting period, we assess the allowance for uncollectible accounts based on historical experience, current conditions, and consideration of expected future conditions. Circumstances which could affect our estimates include, but are not limited to, customer credit issues, the level of natural gas prices, customer deposits, and general economic conditions.

Gas stored underground — Our gas stored underground is comprised of natural gas injected into storage to support the winter season withdrawals for our distribution operations. The average cost method is used for all of our distribution operations. Gas in storage that is retained as cushion gas to maintain reservoir pressure is classified as property, plant and equipment and is valued at cost.

Securitized intangible asset — Our securitized intangible asset is recorded on AEK and represents the Securitized Utility Tariff Property acquired from Atmos Energy in fiscal 2023. See Note 10 to the consolidated financial statements. The securitized intangible asset is stated at cost, net of accumulated amortization, and is amortized over the life of the asset in proportion to the pattern of economic benefit based on expected future undiscounted cash flows. At the end of its life, this securitized intangible asset will have no residual value.

Property, plant and equipment — Regulated property, plant and equipment is stated at original cost, net of contributions in aid of construction. The cost of additions includes direct construction costs, payroll related costs (taxes, the service cost portion of pension expense and other benefits), administrative and general costs, and an allowance for funds used during construction (AFUDC). AFUDC represents the capitalizable total cost of funds used to finance the construction of major projects.

The following table details amounts capitalized for the fiscal year ended September 30.

		2024		2023		2022
		2025		2024		2023
Component of AFUDC	Statement of Comprehensive Income Location	(In thousands)
Debt	Interest charges	$	1421,~~655~~104	$	1514,~~808~~655	$	1215,~~153~~808
Equity	Other non-operating income	5875,~~234~~425		6458,~~019~~234		4564,~~505~~019
		$	7296,~~889~~529	$	7972,~~827~~889	$	5779,~~658~~827

Major renewals, including replacement pipe, and betterments that are recoverable through our regulatory rate base are capitalized while the costs of maintenance and repairs that are not capitalizable are charged to expense as incurred. The costs of large projects are accumulated in construction in progress until the project is completed. When the project is completed, tested, and placed in service, the balance is transferred to the regulated plant in service account included in the rate base and depreciation begins.

Regulated property, plant and equipment is depreciated at various rates on a straight-line basis. These rates are approved by our regulatory commissions and are comprised of two components: one based on average service life and one based on cost of removal. Accordingly, we recognize our cost of removal expense as a component of depreciation expense. The related cost of removal accrual is reflected as a regulatory liability on the consolidated balance sheet. At the time property, plant and equipment is retired, removal expenses less salvage, are charged to the regulatory cost of removal accrual. The composite depreciation rate was 2.8 percent for the fiscal year ended September 30, 2025, 2.9 percent for the fiscal year ended September 30, 2024, and 3.0 percent for the fiscal ~~years~~year ended September 30, 2023 ~~and 2022~~.

Other property, plant and equipment is stated at cost. Depreciation is generally computed on the straight-line method for financial reporting purposes based upon estimated useful lives.

Impairment of long-lived assets — We evaluate whether events or circumstances have occurred that indicate that other long-lived assets may not be recoverable or that the remaining useful life may warrant revision. When such events or circumstances are present, we assess the recoverability of long-lived assets by determining whether the carrying value will be recovered through the expected future cash flows. In the event the sum of the expected future cash flows resulting from the use of the asset is less than the carrying value of the asset, an impairment loss equal to the excess of the asset’s carrying value over its fair value is recorded. No impairment losses were recorded for our long-lived assets during the fiscal years ended September 30, ~~2024~~2025, ~~2023~~2024, and ~~2022~~2023.

Goodwill — We annually evaluate our goodwill balances for impairment during our second fiscal quarter or more frequently as impairment indicators arise. During the second quarter of fiscal ~~2024~~2025, we completed our annual goodwill

Table of Contents

ATMOS ENERGY CORPORATION

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS — (Continued)

impairment assessment. We test goodwill for impairment at the reporting unit level on an annual basis and between annual tests if an event occurs or circumstances change that would more likely than not reduce the fair value of the reporting unit. Based on the assessment performed, we determined that our goodwill was not impaired. Although not applicable for the fiscal ~~2024~~2025 analysis, if a qualitative goodwill assessment resulted in impairment indicators, we would then use a present value technique based on discounted cash flows to estimate the fair value of our reporting units. These calculations are dependent on several subjective factors including the timing of future cash flows, future growth rates, and the discount rate. An impairment charge is recognized if the carrying value of a reporting unit’s goodwill exceeds its fair value.

Lease accounting — We determine if an arrangement is a lease at the inception of the agreement based on the terms and conditions in the contract. A contract contains a lease if there is an identified asset and we have the right to control the asset. We are the lessee for substantially all of our leasing activities, which primarily includes operating leases for office and warehouse space, tower space, vehicles, and heavy equipment used in our operations. We are also a lessee in finance leases for certain service centers.

We record a lease liability and a corresponding right of use (ROU) asset for all of our leases with a term greater than 12 months. For lease contracts containing renewal and termination options, we include the option period in the lease term when it is reasonably certain the option will be exercised. We most frequently assume renewal options at the inception of the arrangement for our tower and fleet leases, based on our anticipated use of the assets. Real estate leases that contain a renewal option are evaluated on a lease-by-lease basis to determine if the option period should be included in the lease term. Currently, we have not included material renewal options for real estate leases in our ROU asset or lease liability.

The lease liability represents the present value of all lease payments over the lease term. We do not include short-term leases in the calculation of our lease liabilities. The discount rate used to determine the present value of the lease liability is the rate implicit in the lease unless that rate cannot be readily determined. We use the implicit rate stated in the agreement to determine the lease liability for our fleet leases. We use our corporate collateralized incremental borrowing rate as the discount rate for all other lease agreements. This rate is appropriate because we believe it represents the rate we would have incurred to borrow funds to acquire the leased asset over a similar term. We calculated this rate using a combination of inputs, including our current credit rating, quoted market prices of interest rates for our publicly traded unsecured debt, observable market yield curve data for peer companies with a credit rating one notch higher than our current credit rating, and the lease term.

The ROU asset represents the right to use the underlying asset for the lease term, and is equal to the lease liability, adjusted for prepaid or accrued lease payments and any lease incentives that have been paid to us or when we are reasonably certain to incur costs equal to or greater than the allowance defined in the contract. We bundle our lease and non-lease components as a single component for all asset classes.

Variable payments included in our leasing arrangements are expensed in the period in which the obligation for these payments is incurred. Variable payments are dependent on usage, output or may vary for other reasons. Most of our variable lease expense is related to tower leases that have escalating payments based on changes to a stated CPI index, and usage of certain office equipment.

We have not provided material residual value guarantees for our leases, nor do our leases contain material restrictions or covenants.

Marketable securities — As of September 30, ~~2024~~2025, we hold marketable securities classified as either equity or debt securities. Changes in fair value of our equity securities are recorded in net income, while debt securities, which are considered available-for-sale securities, are reported at market value with unrealized gains and losses shown as a component of accumulated other comprehensive income (loss).

We regularly evaluate the performance of our available-for-sale debt securities on an investment by investment basis for impairment, taking into consideration the securities’ purpose, volatility, and current returns. If a determination is made that a security will likely be sold before the recovery of its cost, the related investment is written down to its estimated fair value.

Financial instruments and hedging activities — We use financial instruments to mitigate commodity price risk in our distribution and pipeline and storage segments and to mitigate interest rate risk. The objectives and strategies for using financial instruments have been tailored to our business and are discussed in Note 16 to the consolidated financial statements.

We record all of our financial instruments on the balance sheet at fair value, with the exception of normal purchases and normal sales that are expected to result in physical delivery, with changes in fair value ultimately recorded in the statement of comprehensive income. These financial instruments are reported as risk management assets and liabilities and are classified as current or noncurrent other assets or liabilities based upon the anticipated settlement date of the underlying financial instrument. We record the cash flow impact of our financial instruments in operating cash flows based upon their balance sheet classification.

Table of Contents

ATMOS ENERGY CORPORATION

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS — (Continued)

The timing of when changes in fair value of our financial instruments are recorded in the statement of comprehensive income depends on whether the financial instrument has been designated and qualifies as a part of a hedging relationship or if regulatory rulings require a different accounting treatment. Changes in fair value for financial instruments that do not meet one of these criteria are recognized in the statement of comprehensive income as they occur.

Financial Instruments Associated with Commodity Price Risk

In our distribution segment, the costs associated with and the realized gains and losses arising from the use of financial instruments to mitigate commodity price risk are included in our purchased gas cost adjustment mechanisms in accordance with regulatory requirements. Therefore, changes in the fair value of these financial instruments are initially recorded as a component of deferred gas costs and recognized in the consolidated statements of comprehensive income as a component of purchased gas cost when the related costs are recovered through our rates and recognized in revenue in accordance with accounting principles generally accepted in the United States. Accordingly, there is no earnings impact on our distribution segment as a result of the use of these financial instruments.

Financial Instruments Associated with Interest Rate Risk

In connection with the planned issuance of long-term debt, we may use financial instruments to manage interest rate risk. We currently manage this risk through the use of forward starting interest rate swaps to fix the Treasury yield component of the interest cost associated with anticipated financings. We designate these financial instruments as cash flow hedges at the time the agreements are executed. Unrealized gains and losses associated with the instruments are recorded as a component of accumulated other comprehensive income (loss). When the instruments settle, the realized gain or loss is recorded as a component of accumulated other comprehensive income (loss) and recognized as a component of interest charges over the life of the related financing arrangement. As of September 30, ~~2024~~2025 and ~~2023~~2024, no cash was required to be held in margin accounts.

Fair Value Measurements — We report certain assets and liabilities at fair value, which is defined as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date (exit price). We primarily use quoted market prices and other observable market pricing information in valuing our financial assets and liabilities and minimize the use of unobservable pricing inputs in our measurements.

Fair-value estimates also consider our own creditworthiness and the creditworthiness of the counterparties involved. Our counterparties consist primarily of financial institutions and major energy companies. This concentration of counterparties may materially impact our exposure to credit risk resulting from market, economic, or regulatory conditions. We seek to minimize counterparty credit risk through an evaluation of their financial condition and credit ratings and the use of collateral requirements under certain circumstances.

Amounts reported at fair value are subject to potentially significant volatility based upon changes in market prices, including, but not limited to, the valuation of the portfolio of our contracts, maturity, and settlement of these contracts and newly originated transactions and interest rates, each of which directly affect the estimated fair value of our financial instruments. We believe the market prices and models used to value these financial instruments represent the best information available with respect to closing exchange and over-the-counter quotations, time value, and volatility factors underlying the contracts. Values are adjusted to reflect the potential impact of an orderly liquidation of our positions over a reasonable period of time under then current market conditions.

Authoritative accounting literature establishes a fair value hierarchy that prioritizes the inputs used to measure fair value based on observable and unobservable data. The hierarchy categorizes the inputs into three levels, with the highest priority given to unadjusted quoted prices in active markets for identical assets and liabilities (Level 1) and the lowest priority given to unobservable inputs (Level 3). The levels of the hierarchy are described below:

Level 1 — Represents unadjusted quoted prices in active markets for identical assets or liabilities. An active market for the asset or liability is defined as a market in which transactions for the asset or liability occur with sufficient frequency and volume to provide pricing information on an ongoing basis. Prices actively quoted on national exchanges are used to determine the fair value of most of our assets and liabilities recorded on our balance sheet at fair value.

Our Level 1 measurements consist primarily of our debt and equity securities. The Level 1 measurements for investments in the Atmos Energy Corporation Master Retirement Trust (the Master Trust), Supplemental Executive Benefit Plan, and postretirement benefit plan consist primarily of exchange-traded financial instruments.

Level 2 — Represents pricing inputs other than quoted prices included in Level 1 that are either directly or indirectly observable for the asset or liability as of the reporting date. These inputs are derived principally from, or corroborated by, observable market data. Our Level 2 measurements primarily consist of non-exchange-traded financial instruments, such as over-the-counter options and swaps and municipal and corporate bonds where market data for pricing is observable. The Level

Table of Contents

ATMOS ENERGY CORPORATION

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS — (Continued)

2 measurements for investments in our Master Trust, Supplemental Executive Benefit Plan, and postretirement benefit plan consist primarily of non-exchange traded financial instruments such as corporate bonds and government securities.

Level 3 — Represents generally unobservable pricing inputs which are developed based on the best information available, including our own internal data, in situations where there is little if any market activity for the asset or liability at the measurement date. The pricing inputs utilized reflect what a market participant would use to determine fair value. We currently do not have any Level 3 investments.

Pension and other postretirement plans — Pension and other postretirement plan costs and liabilities are determined on an actuarial basis and are affected by numerous assumptions and estimates including the market value of plan assets, estimates of the expected return on plan assets, assumed discount rates, and current demographic and actuarial mortality data. Our measurement date is September 30. The assumed discount rate and the expected return are the assumptions that generally have the most significant impact on our pension costs and liabilities. The assumed discount rate, the assumed health care cost trend rate, and assumed rates of retirement generally have the most significant impact on our postretirement plan costs and liabilities.

The discount rate is utilized principally in calculating the actuarial present value of our pension and postretirement obligation and net pension and postretirement cost. When establishing our discount rate, we consider high quality corporate bond rates based on bonds available in the marketplace that are suitable for settling the obligations, changes in those rates from the prior year, and the implied discount rate that is derived from matching our projected benefit disbursements with currently available high quality corporate bonds.

The expected long-term rate of return on assets is utilized in calculating the expected return on plan assets component of the annual pension and postretirement plan cost. We estimate the expected return on plan assets by evaluating expected bond returns, equity risk premiums, asset allocations, the effects of active plan management, the impact of periodic plan asset rebalancing, and historical performance. We also consider the guidance from our investment advisors when making a final determination of our expected rate of return on assets. To the extent the actual rate of return on assets realized over the course of a year is greater than or less than the assumed rate, that year’s annual pension or postretirement plan cost is not affected. Rather, this gain or loss is amortized over the expected future working lifetime of the plan participants.

The expected return on plan assets is then calculated by applying the expected long-term rate of return on plan assets to the market-related value of the plan assets. The market-related value of our plan assets represents the fair market value of the plan assets, adjusted to smooth out short-term market fluctuations over a five-year period. The use of this calculation will delay the impact of current market fluctuations on the pension expense for the period.

We use a corridor approach to amortize actuarial gains and losses. Under this approach, net gains or losses in excess of ten percent of the larger of the pension benefit obligation or the market-related value of the assets are amortized on a straight-line basis. The period of amortization is the average remaining service of active participants who are expected to receive benefits under the plan.

We estimate the assumed health care cost trend rate used in determining our annual postretirement net cost based upon our actual health care cost experience, the effects of recently enacted legislation, and general economic conditions. Our assumed rate of retirement is estimated based upon the annual review of our participant census information as of the measurement date.

We present only the current service cost component of the net benefit cost within operations and maintenance expense in the consolidated statements of comprehensive income. The remaining components of net benefit cost are recorded in other non-operating income (expense) in our consolidated statements of comprehensive income. Only the service cost component of net benefit cost is eligible for capitalization and we continue to capitalize these costs into property, plant and equipment. Additionally, we defer into a regulatory asset or liability the portion of non-service components of net periodic benefit cost that are capitalizable for regulatory purposes.

Income taxes — Income taxes are determined based on the liability method, which results in income tax assets and liabilities arising from temporary differences. Temporary differences are differences between the tax bases of assets and liabilities and their reported amounts in the financial statements that will result in taxable or deductible amounts in future years. The liability method requires the effect of tax rate changes on accumulated deferred income taxes to be reflected in the period in which the rate change was enacted. The liability method also requires that deferred tax assets be reduced by a valuation allowance unless it is more likely than not that the assets will be realized.

The Company may recognize the tax benefit from uncertain tax positions only if it is at least more likely than not that the tax position will be sustained on examination by the taxing authorities, based on the technical merits of the position. The tax benefits recognized in the financial statements from such a position should be measured based on the largest benefit that has a greater than fifty percent likelihood of being realized upon settlement with the taxing authorities. We recognize accrued interest

Table of Contents

ATMOS ENERGY CORPORATION

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS — (Continued)

related to unrecognized tax benefits as a component of interest charges. We recognize penalties related to unrecognized tax benefits as a component of miscellaneous income (expense) in accordance with regulatory requirements.

Tax collections — We are allowed to recover from customers revenue-related taxes that are imposed upon us. We record such taxes as operating expenses and record the corresponding customer charges as operating revenues. However, we do collect and remit various other taxes on behalf of various governmental authorities, and we record these amounts in our consolidated balance sheets on a net basis. We do not collect income taxes from our customers on behalf of governmental authorities.

Contingencies — In the normal course of business, we are confronted with issues or events that may result in a contingent liability. These generally relate to lawsuits, claims made by third parties, or the action of various regulatory agencies. For such matters, we record liabilities when they are considered probable and estimable, based on currently available facts and our estimates of the ultimate outcome or resolution of the liability in the future. We maintain liability insurance for various risks associated with the operation of our natural gas pipelines and facilities, including for property damage and bodily injury. These liability insurance policies generally require us to be responsible for the first $1.0 million (self-insured retention) of each incident. To the extent a loss contingency exceeds the self-insurance retention, we record an insurance receivable when recovery is considered probable. Upon reaching a settlement, the loss contingency is deemed resolved and recorded in accounts payable and accrued liabilities until paid. Loss contingencies and any related insurance recovery receivables reflect our best estimate of these amounts as of the date of this report. Actual results may differ from estimates, depending on actual outcomes or changes in the facts or expectations surrounding each potential exposure.

We record a liability at fair value for an asset retirement obligation when the legal obligation to retire the asset has been incurred with an offsetting increase to the carrying value of the related asset. We believe we have a legal obligation to retire our natural gas storage facilities. However, we have not recognized an asset retirement obligation associated with our storage facilities because we are not able to determine the settlement date of this obligation as we do not anticipate taking our storage facilities out of service permanently. Therefore, we cannot reasonably estimate the fair value of this obligation.

Subsequent events — Except as noted in Note 7 and Note 8 to the consolidated financial statements regarding the execution of a new lease and the public offering of senior notes, no events occurred subsequent to the balance sheet date that would require recognition or disclosure in the consolidated financial statements.

Recent accounting pronouncements

~~In November 2023, the Financial~~ Accounting ~~Standards~~pronouncements ~~Board~~adopted ~~(FASB)~~in issued guidance which provides updates to qualitative and quantitative reportable segment disclosure requirements, including enhanced disclosures about significant segment expenses and increased interim disclosure requirements, among others. The amendment is effective for fiscal ~~years beginning after December 15, 2023, and interim periods within fiscal years beginning after December 15, 2024. Early~~2025

~~adoption~~In isNovember ~~permitted~~2023, ~~and~~ the ~~amendments~~Financial ~~should~~Accounting beStandards ~~applied~~Board ~~retrospectively.~~(FASB) ~~This~~issued ~~amendment~~guidance ~~will~~which beprovides ~~effective~~updates ~~for~~to ~~our~~qualitative ~~Form~~and ~~10-K~~quantitative ~~for~~reportable ~~fiscal~~segment ~~2025~~disclosure ~~and~~requirements, ~~our~~including ~~Form~~enhanced ~~10-Q~~disclosures ~~for~~about ~~the~~significant ~~first~~segment ~~quarter~~expenses ofand ~~fiscal~~increased ~~2026~~interim disclosure requirements, among others. We ~~are~~adopted ~~currently~~this ~~evaluating~~amendment ~~the~~as ~~impact~~of ~~this~~September 30, ~~may~~2025 ~~have~~and onapplied ~~our~~it ~~financial~~retrospectively ~~statement~~for ~~disclosures~~all periods presented. See Note 4 for further discussion.

In December 2023, the FASB issued guidance which provides qualitative and quantitative updates to the rate reconciliation and income taxes paid disclosures, among others, in order to enhance the transparency of income tax disclosures, including consistent categories and greater disaggregation of information in the rate reconciliation and disaggregation by jurisdiction of income taxes paid. ~~The~~We ~~amendment~~early isadopted ~~effective~~this ~~for~~amendment ~~fiscal~~as ~~years~~of ~~beginning after December 15~~September 30, ~~2024,~~2025 ~~with~~and ~~early adoption permitted. The amendments should be~~ applied ~~prospectively;~~it ~~however,~~retrospectively ~~retrospective~~for ~~application~~all isperiods ~~also permitted~~presented. ~~This~~See ~~amendment~~Note ~~will~~15 ~~be effective~~ for ~~our~~further ~~Form 10-K for fiscal 2026~~discussion. ~~We are currently evaluating the impact this may have on our financial statement disclosures.~~

InAccounting ~~November~~pronouncements ~~2024, the FASB issued guidance~~ that will ~~require~~be ~~more detailed information about the types of expenses in commonly presented expense captions. The amendment is~~ effective ~~for fiscal years beginning~~ after ~~December 15, 2026, and interim reporting periods beginning after December 15, 2027. Early adoption is permitted. This amendment will be effective for our Form 10-K for~~ fiscal ~~2027 and our Form 10-Q for the first quarter of fiscal 2028. We are currently evaluating the impact this may have on our financial statement disclosures.~~2025

3In November 2024, the FASB issued guidance that will require more detailed information about the types of expenses in commonly presented expense captions. ~~Regulation~~ The amendment is effective for fiscal years beginning after December 15, 2026, and interim reporting periods beginning after December 15, 2027. Early adoption is permitted. This amendment will be effective for our Form 10-K for fiscal 2028 and our Form 10-Q for the first quarter of fiscal 2029. We are currently evaluating the impact this may have on our financial statement disclosures.

~~Our~~In ~~distribution~~September ~~and~~2025, ~~pipeline~~the ~~and~~FASB ~~storage~~issued ~~operations~~guidance ~~are~~which ~~subject~~provides toqualitative ~~regulation~~updates ~~with respect~~ to ~~rates,~~the ~~service,~~determination ~~maintenance~~ of ~~accounting~~capitalizing ~~records,~~internal-use ~~and~~software ~~various~~costs ~~other matters~~ by expanding the ~~respective~~scope ~~regulatory~~to ~~authorities~~allow infor ~~the~~various ~~states~~software indevelopment ~~which~~methods. weThe ~~operate,~~amendment ~~which~~is ~~creates~~effective ~~regulatory~~for ~~assets~~fiscal ~~and~~years ~~liabilities~~beginning ~~that~~after ~~are~~December ~~recovered~~15, ~~from~~2027. orEarly ~~refunded~~adoption tois ~~customers~~permitted, ~~over~~and ~~time through~~ the ~~ratemaking~~amendment ~~process.~~may ~~Substantially~~be ~~all~~applied ofprospectively, ~~our~~retrospectively, ~~regulatory~~or ~~assets~~with ~~are~~a ~~recorded~~modified astransition aapproach. ~~component~~This ofamendment ~~other~~will ~~current~~be ~~assets~~effective ~~and~~for ~~deferred~~our ~~charges~~Form ~~and~~10-K ~~other~~for ~~assets~~fiscal 2029 and our ~~regulatory~~Form ~~liabilities~~10-Q ~~are~~for ~~recorded~~the asfirst aquarter ~~component~~ of ~~other~~fiscal ~~current liabilities and deferred credits and other liabilities~~2029. ~~Deferred~~We ~~gas costs~~ are ~~recorded~~currently ~~either~~evaluating inthe ~~other~~impact ~~current~~this ~~assets~~may orhave ~~liabilities~~on ~~and~~our ~~the~~financial ~~long-term~~statement ~~portion~~ disclosures.

Table of Contents

ATMOS ENERGY CORPORATION

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS — (Continued)

~~of regulatory excess deferred taxes and regulatory cost of removal obligation are reported separately~~3. ~~Significant regulatory assets and liabilities as of September 30, 2024 and 2023 included the following:~~ Regulation

	September 30
	2024		2023
	(In thousands)
Regulatory assets:
Pension and postretirement benefit costs	$	11,243	$	20,629
Infrastructure mechanisms (1)	246,734		229,996
Winter Storm Uri incremental costs	10,373		32,115
Deferred gas costs	159,762		148,297
Regulatory excess deferred taxes (2)	51,380		47,549
Recoverable loss on reacquired debt	3,070		3,238
Deferred pipeline record collection costs	41,742		54,008
APT annual System Safety and Integrity Rider (3)	38,632		—
Other	16,454		19,096
	$	579,390	$	554,928
Regulatory liabilities:
Regulatory excess deferred taxes (2)	$	257,001	$	384,513
Regulatory cost of removal obligation	607,032		582,867
Deferred gas costs	9,142		23,093
APT annual adjustment mechanism	73,119		49,894
Pension and postretirement benefit costs	247,250		215,913
Other	34,338		28,054
	$	1,227,882	$	1,284,334

Our distribution and pipeline and storage operations are subject to regulation with respect to rates, service, maintenance of accounting records, and various other matters by the respective regulatory authorities in the states in which we operate, which creates regulatory assets and liabilities that are recovered from or refunded to customers over time through the ratemaking process. Substantially all of our regulatory assets are recorded as a component of other current assets and deferred charges and other assets and our regulatory liabilities are recorded as a component of other current liabilities and deferred credits and other liabilities. Deferred gas costs are recorded either in other current assets or liabilities and the long-term portion of regulatory excess deferred taxes and regulatory cost of removal obligation are reported separately. Significant regulatory assets and liabilities as of September 30, 2025 and 2024 included the following:


	September 30
	2025		2024
	(In thousands)
Regulatory assets:
Pension and postretirement benefit costs	$	262	$	11,243
Infrastructure mechanisms (1)	314,047		246,734
Winter Storm Uri incremental costs	5,841		10,373
Deferred gas costs	140,626		159,762
Regulatory excess deferred taxes (2)	49,793		51,380
Recoverable loss on reacquired debt	2,903		3,070
Deferred pipeline record collection costs	39,035		41,742
System Safety and Integrity Riders (3)	43,625		38,632


Other	12,597		16,454
	$	608,729	$	579,390
Regulatory liabilities:
Regulatory excess deferred taxes (2)	$	190,274	$	257,001

Regulatory cost of removal obligation	641,019		607,032
Deferred gas costs	6,879		9,142

APT annual adjustment mechanism	99,393		73,119
Pension and postretirement benefit costs	291,351		247,250
Other	40,732		34,338
	$	1,269,648	$	1,227,882

(1)Infrastructure mechanisms in Texas, Louisiana, and Tennessee allow for the deferral of all eligible expenses associated with capital expenditures incurred pursuant to these rules, including the recording of interest on the deferred expenses until the next rate proceeding (rate case or annual rate filing), at which time investment and costs would be recovered through base rates.

(2)Regulatory excess deferred taxes represent changes in our net deferred tax liability related to our cost of service ratemaking due to the enactment of the Tax Cuts and Jobs Act of 2017 (the "TCJA"), ~~and~~ a Kansas legislative change enacted in fiscal 2020, and a Louisiana legislative change enacted in fiscal 2025. See Notes 13 and 15 to the consolidated financial statements for further information.

(3)In our APT's ~~general~~and ~~rate~~West ~~case~~Texas ~~settlement~~Divisions inand ~~December~~portions ~~2023~~of our Mid-Tex Division, the RRC has approved athe ~~new~~deferral ~~annual~~of ~~compliance filing that allows APT to recover~~ certain system safety and integrity costs incurred ~~each~~in ~~year.~~excess ~~Costs~~of ~~above~~ a specified benchmark. These costs are ~~deferred~~eligible ~~onto~~for ~~the~~recovery ~~balance~~in ~~sheet~~a asfuture ~~incurred.~~filing ~~Once~~after ~~the~~such ~~filing~~costs isare approved by the RRC~~, the revenue and expense are recognized over 12 months resulting in no impact to operating income~~.

~~Securitization~~4. Segment Information

~~Kansas~~As of September 30, 2025, we manage and review our consolidated operations through the following two reportable segments:

~~See~~•The ~~Note~~distribution 10segment tois ~~the~~comprised ~~consolidated~~of ~~financial~~our ~~statements~~regulated ~~for~~natural ~~securitization~~gas distribution and ~~other information~~ related tosales ~~Atmos~~operations ~~Energy~~in ~~Kansas~~eight ~~Securitization I, LLC (AEK)~~states.

InOur ~~Texas,~~determination weof ~~recorded~~reportable asegments ~~$2.02 billion~~considers ~~regulatory asset in fiscal 2021 for costs incurred during Winter Storm Uri. In 2021,~~ the ~~Texas~~strategic ~~Legislature~~operating ~~passed~~units ~~House~~under ~~Bill 1520,~~ which ~~authorized~~we ~~the~~manage ~~RRC~~sales toof ~~issue~~various aproducts ~~statewide~~and ~~securitization~~services ~~financing order directing the Texas Public Finance Authority (TPFA)~~ to ~~issue~~customers. ~~bonds~~Although ~~(customer~~our ~~rate~~distribution ~~relief~~segment ~~bonds)~~operations ~~for~~are ~~gas~~geographically ~~utilities~~dispersed, ~~that~~they ~~chose~~are toaggregated ~~participate to recover extraordinary costs incurred to secure gas supply~~ and toreported ~~provide~~as ~~service~~a ~~during~~single ~~Winter~~segment ~~Storm~~as ~~Uri,~~each ~~and~~natural ~~to restore~~ gas ~~utility~~distribution ~~systems~~division ~~after~~has ~~that~~similar ~~event,~~economic ~~thereby~~characteristics. ~~providing~~In ~~rate relief to customers by extending the period during which these extraordinary costs would otherwise be recovered and supporting the financial strength and stability of gas utility companies.~~

In March 2023, the Texas Natural Gas Securitization Finance Corporation (the Finance Corporation), with the authority of the TPFA, issued $3.5 billion in customer rate relief bonds with varying scheduled final maturities from 12 to 18 years. The bonds are obligations of the Finance Corporation, payable from the customer rate relief charges and other bond collateral, and are not an obligation of Atmos Energy. We collected $2.02 billion of this amount and relieved the regulatory asset.

Table of Contents

ATMOS ENERGY CORPORATION

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS — (Continued)

Weaddition, ~~began~~because ~~collecting~~ the ~~customer~~pipeline ~~rate~~and ~~relief~~storage ~~charges~~operations onof ~~October~~our 1,Atmos ~~2023,~~Pipeline-Texas division and ~~any~~our ~~such~~natural ~~property~~gas ~~collected~~transmission isoperations ~~solely~~in ~~owned~~Louisiana byhave ~~the~~similar ~~Finance~~economic ~~Corporation~~characteristics, ~~and~~they ~~not~~have ~~available~~been toaggregated ~~pay~~and ~~creditors~~reported ofas ~~Atmos~~a ~~Energy~~single segment.

Additionally, we deferred $32.4 million in carrying costs incurred after September 1, 2022. During fiscal 2024, we have recovered $22.0 million of this amount. Of the remaining $10.4 million, $4.0 million has been recorded as a current asset in other current assets as of September 30, 2024 and $6.4 million has been recorded as a long-term asset in deferred charges and other assets as of September 30, 2024 as we anticipate recovering this amount in future regulatory proceedings.

4. Segment Information

As of September 30, 2024, we manage and review our consolidated operations through the following two reportable segments:

•The distribution segment is comprised of our regulated natural gas distribution and related sales operations in eight states.

Our determination of reportable segments considers the strategic operating units under which we manage sales of various products and services to customers. Although our distribution segment operations are geographically dispersed, they are aggregated and reported as a single segment as each natural gas distribution division has similar economic characteristics. In addition, because the pipeline and storage operations of our Atmos Pipeline-Texas division and our natural gas transmission operations in Louisiana have similar economic characteristics, they have been aggregated and reported as a single segment.

The accounting policies of the segments are the same as those described in the summary of significant accounting policies. We evaluate performance based on net income or loss of the respective operating units. We allocate interest and pension expense to the pipeline and storage segment; however, there is no debt or pension liability recorded on the pipeline and storage segment balance sheet. All material intercompany transactions have been eliminated; however, we have not eliminated intercompany profits when such amounts are probable of recovery under the affiliates’ rate regulation process. Income taxes are allocated to each segment as if each segment’s income taxes were calculated on a separate return basis.

~~Income~~Our ~~statements~~Chief ~~and~~Operating ~~capital~~Decision ~~expenditures~~Maker by(CODM), the Chief Executive Officer, evaluates performance for each reportable segment ~~are~~based ~~shown~~on innet income, which is used to help inform the ~~following~~allocation ~~tables~~of resources as part of the Company's process for budgeting and monitoring financial performance.

	Year Ended September 30, 2024
	Distribution		Pipeline and Storage		Eliminations		Consolidated
	(In thousands)
Operating revenues from external parties	$	3,912,134	$	253,053	$	—	$	4,165,187
Intersegment revenues	3,007		684,976		(687,983)		—
Total operating revenues	3,915,141		938,029		(687,983)		4,165,187
Purchased gas cost	1,620,515		146		(686,968)		933,693
Operation and maintenance expense	601,370		218,782		(1,015)		819,137
Depreciation and amortization expense	491,982		177,990		—		669,972
Taxes, other than income	346,840		40,183		—		387,023
Operating income	854,434		500,928		—		1,355,362
Other non-operating income	30,106		40,940		—		71,046
Interest charges	117,086		73,546		—		190,632
Income before income taxes	767,454		468,322		—		1,235,776
Income tax expense	96,041		96,840		—		192,881
Net income	$	671,413	$	371,482	$	—	$	1,042,895
Capital expenditures	$	2,249,280	$	687,844	$	—	$	2,937,124

Income statement information and capital expenditures by segment are shown in the following tables.


	Year Ended September 30, 2025
	Distribution		Pipeline and Storage		Total of Reportable Segments
	(In thousands)
Operating revenues from external parties	$	4,422,355	$	280,400	$	4,702,755
Intersegment revenues	3,042		784,900		787,942
Total operating revenues	4,425,397		1,065,300		5,490,697
Operation and maintenance expense	644,924		229,986		874,910
Depreciation and amortization expense (2)	543,840		190,905		734,745
Interest charges (2)	99,226		72,452		171,678
Income tax expense (2)	150,961		128,319		279,280
Other segment items (1)	2,239,665		(8,335)		2,231,330
Net income (2)	$	746,781	$	451,973	$	1,198,754
Capital expenditures (2)	$	2,662,703	$	898,696	$	3,561,399
Reconciliation to consolidated total operating revenues:
Total operating revenues of reportable segments					$	5,490,697
Elimination of intersegment revenues					(787,942)
Consolidated total operating revenues					$	4,702,755

Table of Contents

ATMOS ENERGY CORPORATION

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS — (Continued)

	Year Ended September 30, 2023
	Year Ended September 30, 2024
	Distribution		Pipeline and Storage		~~Eliminations~~Total of Reportable Segments		~~Consolidated~~
	(In thousands)
Operating revenues from external parties	$	43,~~096~~912,~~661~~134	$	~~178~~253,~~696~~053	$	—4,165,187	$	~~4,275,357~~
Intersegment revenues	3,~~029~~007		~~606~~684,~~478~~976		~~(609~~687,~~507)~~983		—
Total operating revenues	43,~~099~~915,~~690~~141		~~785~~938,~~174~~029		~~(609~~4,~~507)~~853,170		~~4,275,357~~
Purchased gas cost	2,061,920		(1,220)		(608,527)		1,452,173
Operation and maintenance expense	589,864		218,571		808,435
Operation and maintenance expense	565,179		200,707		(980)		764,906
Depreciation and amortization expense (2)	491,982		177,990		669,972
Depreciation and amortization expense	434,721		169,606		—		604,327
Interest charges (2)	117,086		73,546		190,632
Taxes, other than income	345,244		41,560		—		386,804
Income tax expense (2)	96,041		96,840		192,881
Operating income	692,626		374,521		—		1,067,147
Other segment items (1)	1,948,755		(400)		1,948,355
Other non-operating income	24,988		44,787		—		69,775
Net income (2)	$	671,413	$	371,482	$	1,042,895
Interest charges	77,185		60,096		—		137,281
Capital expenditures (2)	$	2,249,280	$	687,844	$	2,937,124
Income before income taxes	640,429		359,212		—		999,641
Reconciliation to consolidated total operating revenues:
Income tax expense	60,032		53,747		—		113,779
Total operating revenues of reportable segments					$	4,853,170
Net income	$	580,397	$	305,465	$	—	$	885,862
Elimination of intersegment revenues					(687,983)
Capital expenditures	$	1,927,125	$	878,848	$	—	$	2,805,973
Consolidated total operating revenues					$	4,165,187

	Year Ended September 30, 2022
	Year Ended September 30, 2023
	Distribution		Pipeline and Storage		~~Eliminations~~Total of Reportable Segments		~~Consolidated~~
	(In thousands)
Operating revenues from external parties	$	4,~~031~~096,~~936~~661	$	~~169~~178,~~726~~696	$	—4,275,357	$	~~4,201,662~~
Intersegment revenues	3,~~258~~029		~~523~~606,~~934~~478		~~(527~~609,~~192)~~507		—
Total operating revenues	4,~~035~~099,~~194~~690		~~693~~785,~~660~~174		~~(527~~4,~~192)~~884,864		~~4,201,662~~
Purchased gas cost	2,210,302		(1,583)		(526,063)		1,682,656
Operation and maintenance expense	543,078		200,580		743,658
Operation and maintenance expense	518,443		192,847		(1,129)		710,161
Depreciation and amortization expense (2)	434,721		169,606		604,327
Depreciation and amortization expense	387,858		147,797		—		535,655
Interest charges (2)	77,185		60,096		137,281
Taxes, other than income	314,046		38,162		—		352,208
Income tax expense (2)	60,032		53,747		113,779
Operating income	604,545		316,437		—		920,982
Other segment items (1)	2,404,277		(4,320)		2,399,957
Other non-operating income	6,946		26,791		—		33,737
Net income (2)	$	580,397	$	305,465	$	885,862
Interest charges	49,921		52,890		—		102,811
Capital expenditures (2)	$	1,927,125	$	878,848	$	2,805,973
Income before income taxes	561,570		290,338		—		851,908
Reconciliation to consolidated total operating revenues:
Income tax expense	39,593		37,917		—		77,510
Total operating revenues of reportable segments					$	4,884,864
Net income	$	521,977	$	252,421	$	—	$	774,398
Elimination of intersegment revenues					(609,507)
Capital expenditures	$	1,675,798	$	768,622	$	—	$	2,444,420
Consolidated total operating revenues					$	4,275,357

~~The~~(1)Other ~~following~~segment ~~table~~items ~~summarizes~~consist ~~our~~of ~~revenues~~purchased ~~from~~gas ~~external~~cost, ~~parties~~bad debt expense, ~~excluding~~taxes ~~intersegment~~other ~~revenues~~than income taxes, bythe ~~products~~equity component of AFUDC, community support spending, and ~~services~~other ~~for~~segment ~~the~~income ~~fiscal~~or ~~years~~expense ~~ended~~deemed ~~September~~insignificant 30which are used to reach net income, our measurement of segment profit or loss.

(2)The totals of reportable segments for these items reconcile to consolidated totals.

Table of Contents

ATMOS ENERGY CORPORATION

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS — (Continued)

	2024		2023		2022
	(In thousands)
Distribution revenues:
Gas sales revenues:
Residential	$	2,583,681	$	2,638,689	$	2,492,116
Commercial	1,016,675		1,112,236		1,126,189
Industrial	100,596		151,970		224,632
Public authority and other	52,180		62,476		66,956
Total gas sales revenues	3,753,132		3,965,371		3,909,893
Transportation revenues	132,608		119,371		110,905
Other gas revenues	26,394		11,919		11,138
Total distribution revenues	3,912,134		4,096,661		4,031,936
Pipeline and storage revenues	253,053		178,696		169,726
Total operating revenues	$	4,165,187	$	4,275,357	$	4,201,662

The following table summarizes our revenues from external parties, excluding intersegment revenues, by products and services for the fiscal years ended September 30.

Balance sheet information at September 30, 2024 and 2023 by segment is presented in the following tables.



	2025		2024		2023
	(In thousands)
Distribution revenues:
Gas sales revenues:
Residential	$	2,916,245	$	2,583,681	$	2,638,689
Commercial	1,154,591		1,016,675		1,112,236
Industrial	122,576		100,596		151,970
Public authority and other	52,606		52,180		62,476
Total gas sales revenues	4,246,018		3,753,132		3,965,371
Transportation revenues	149,853		132,608		119,371
Other gas revenues	26,484		26,394		11,919
Total distribution revenues	4,422,355		3,912,134		4,096,661
Pipeline and storage revenues	280,400		253,053		178,696
Total operating revenues	$	4,702,755	$	4,165,187	$	4,275,357

	September 30, 2024
	Distribution		Pipeline and Storage		Eliminations		Consolidated
	(In thousands)
Property, plant and equipment, net	$	16,372,659	$	5,831,708	$	—	$	22,204,367
Total assets	$	24,328,877	$	6,181,558	$	(5,315,970)	$	25,194,465

Balance sheet information at September 30, 2025 and 2024 by segment is presented in the following tables.

	September 30, 2023
	September 30, 2025
	Distribution		Pipeline and Storage		~~Eliminations~~Total of Reportable Segments		~~Consolidated~~
	(In thousands)
Property, plant and equipment, net	$	14,402,578	$	5,204,005	$	—	$	19,606,583
Property, plant and equipment, net (1)	$	18,765,128	$	6,527,862	$	25,292,990
Total assets	$	2127,~~716~~296,~~467~~805	$	56,~~504~~896,~~972~~646	$	(434,~~704~~193,~~471)~~451	$	~~22,516,968~~
Reconciliation to consolidated assets:
Total assets of reportable segments					$	34,193,451
Elimination of intersegment assets					(5,943,929)
Consolidated total assets					$	28,249,522


	September 30, 2024
	Distribution		Pipeline and Storage		Total of Reportable Segments
	(In thousands)
Property, plant and equipment, net (1)	$	16,372,659	$	5,831,708	$	22,204,367
Total assets	$	24,328,877	$	6,181,558	$	30,510,435
Reconciliation to consolidated assets:
Total assets of reportable segments					$	30,510,435
Elimination of intersegment assets					(5,315,970)
Consolidated total assets					$	25,194,465

(1)The total of reportable segments for this item reconciles to consolidated total.

5. Earnings Per Share

We use the two-class method of computing earnings per share because we have participating securities in the form of non-vested restricted stock units with a nonforfeitable right to dividend equivalents, for which vesting is predicated solely on the passage of time. The calculation of earnings per share using the two-class method excludes income attributable to these participating securities from the numerator and excludes the dilutive impact of those shares from the denominator. Basic weighted average shares outstanding is calculated based upon the weighted average number of common shares outstanding during the periods presented. Also, this calculation includes fully vested stock awards that have not yet been issued as common stock. Additionally, the weighted average shares outstanding for diluted EPS includes the incremental effects of the forward sale agreements, discussed in Note 9 to the consolidated financial statements, when the impact is dilutive.

Basic and diluted earnings per share for the fiscal years ended September 30 are calculated as follows:

Table of Contents

ATMOS ENERGY CORPORATION

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS — (Continued)

	2024		2023		2022
	(In thousands, except per share data)
Basic Earnings Per Share
Net income	$	1,042,895	$	885,862	$	774,398
Less: Income allocated to participating securities	553		542		508
Net income available to common shareholders	$	1,042,342	$	885,320	$	773,890
Basic weighted average shares outstanding	152,508		145,121		137,830
Net income per share — Basic	$	6.83	$	6.10	$	5.61
Diluted Earnings Per Share
Net income available to common shareholders	$	1,042,342	$	885,320	$	773,890
Effect of dilutive shares	—		—		—
Net income available to common shareholders	$	1,042,342	$	885,320	$	773,890
Basic weighted average shares outstanding	152,508		145,121		137,830
Dilutive shares	158		45		266
Diluted weighted average shares outstanding	152,666		145,166		138,096
Net income per share — Diluted	$	6.83	$	6.10	$	5.60

stock. Additionally, the weighted average shares outstanding for diluted EPS includes the incremental effects of the forward sale agreements, discussed in Note 9 to the consolidated financial statements, when the impact is dilutive.

Basic and diluted earnings per share for the fiscal years ended September 30 are calculated as follows:


	2025		2024		2023
	(In thousands, except per share data)
Basic Earnings Per Share
Net income	$	1,198,754	$	1,042,895	$	885,862
Less: Income allocated to participating securities	487		553		542
Net income available to common shareholders	$	1,198,267	$	1,042,342	$	885,320
Basic weighted average shares outstanding	158,943		152,508		145,121
Net income per share — Basic	$	7.54	$	6.83	$	6.10









Diluted Earnings Per Share
Net income available to common shareholders	$	1,198,267	$	1,042,342	$	885,320
Effect of dilutive shares	—		—		—
Net income available to common shareholders	$	1,198,267	$	1,042,342	$	885,320
Basic weighted average shares outstanding	158,943		152,508		145,121
Dilutive shares	1,630		158		45
Diluted weighted average shares outstanding	160,573		152,666		145,166
Net income per share — Diluted	$	7.46	$	6.83	$	6.10

6. Revenue and Accounts Receivable

The following tables disaggregates our revenue from contracts with customers by customer type and segment and provides a reconciliation to total operating revenues, including intersegment revenues, for the periods presented.

	Year Ended September 30, 2024
	Year Ended September 30, 2025
	Distribution		Pipeline and Storage
	(In thousands)
Gas sales revenues:
Residential	$	2,~~542~~877,~~438~~456	$	—
Commercial	1,~~006~~145,~~593~~710		—
Industrial	~~100~~122,~~363~~284		—
Public authority and other	51,~~337~~354		—
Total gas sales revenues	34,~~700~~196,~~731~~804		—
Transportation revenues	~~134~~151,~~600~~876		~~982~~1,~~795~~119,015
Miscellaneous revenues	1113,~~836~~123		1512,~~892~~749
Revenues from contracts with customers	34,~~847~~361,~~167~~803		~~998~~1,~~687~~131,764
Alternative revenue program revenues	5249,~~401~~215		(6066,~~658~~464)
Other revenues	1514,~~573~~379		—
Total operating revenues	$	34,~~915~~425,~~141~~397	$	~~938~~1,~~029~~065,300

Table of Contents

ATMOS ENERGY CORPORATION

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS — (Continued)


	Year Ended September 30, 2024
	Distribution		Pipeline and Storage

Gas sales revenues:
Residential	$	2,542,438	$	—
Commercial	1,006,593		—
Industrial	100,363		—
Public authority and other	51,337		—
Total gas sales revenues	3,700,731		—
Transportation revenues	134,600		982,795
Miscellaneous revenues	11,836		15,892
Revenues from contracts with customers	3,847,167		998,687
Alternative revenue program revenues	52,401		(60,658)
Other revenues	15,573		—
Total operating revenues	$	3,915,141	$	938,029


	Year Ended September 30, 2023
	Distribution		Pipeline and Storage

Gas sales revenues:
Residential	$	2,606,658	$	—
Commercial	1,100,773		—
Industrial	151,538		—
Public authority and other	61,345		—
Total gas sales revenues	3,920,314		—
Transportation revenues	121,420		811,968
Miscellaneous revenues	10,044		12,180
Revenues from contracts with customers	4,051,778		824,148
Alternative revenue program revenues	43,139		(38,974)
Other revenues	4,773		—
Total operating revenues	$	4,099,690	$	785,174

	Year Ended September 30, 2022
	Distribution		Pipeline and Storage
Gas sales revenues:
Residential	$	2,472,461	$	—
Commercial	1,120,322		—
Industrial	224,427		—
Public authority and other	66,691		—
Total gas sales revenues	3,883,901		—
Transportation revenues	113,043		707,205
Miscellaneous revenues	10,282		13,679
Revenues from contracts with customers	4,007,226		720,884
Alternative revenue program revenues	26,041		(27,224)
Other revenues	1,927		—
Total operating revenues	$	4,035,194	$	693,660

We have alternative revenue programs in each of our segments. In our distribution segment, we have weather-normalization adjustment mechanisms that serve to mitigate the effects of weather on our revenue. In our pipeline and storage segment, APT has a regulatory mechanism that requires that we share with its tariffed customers 75% of the difference between the total non-tariffed revenues earned during a test period and a revenue benchmark established by the RRC. Other revenues includes AEK revenues (see Note 10 to the consolidated financial statements) and other miscellaneous revenues.

Accounts receivable and allowance for uncollectible accounts

Rollforwards of our allowance for uncollectible accounts for the years ended September 30, ~~2024~~2025, ~~2023~~2024, and ~~2022~~2023 are presented in the table below.

We actively work with our customers experiencing financial hardship to offer flexible payment options and to direct them to aid agencies for financial assistance. Our allowance for uncollectible accounts reflects the expected impact on our customers’ ability to pay. Our allowance for uncollectible accounts also reflects the fact that we have the ability to recover the gas cost portion of uncollectible accounts through our gas cost recovery mechanisms in six states, which covers approximately 89 percent of our residential and commercial customers.

In December 2023, the Mississippi Public Service Commission approved the recovery of uncollectible accounts through our purchased gas cost mechanism over a two-year period rather than through our annual filing mechanism over a one-year period. As a result of this decision, we recorded a $13.9 million reduction to bad debt expense during the first quarter of fiscal

Table of Contents

ATMOS ENERGY CORPORATION

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS — (Continued)

2024. Of this amount, $9.7 million represents future recovery of customer receivables previously written off since April 2022 but not yet recovered through our rates. This amount increased our deferred gas cost regulatory asset. The remaining $4.2 million reduction represents a reversal of our allowance for uncollectible accounts for customer balances that have not yet been written off.

	Allowance for uncollectible accounts
	(In thousands)
Balance, September 30, 2021	$	64,471
Balance, September 30, 2022	$	49,993
Current period provisions	16,576
Write-offs charged against allowance	(32,885)
Recoveries of amounts previously written off	1,831
Balance, September 30, 2022	49,993
Current period provisions	22,353
Write-offs charged against allowance	(33,595)
Recoveries of amounts previously written off	2,089
Balance, September 30, 2023	40,840
Current period provisions	24,843
Write-offs charged against allowance	(26,165)
Recoveries of amounts previously written off	1,730
Mississippi recovery of uncollectible accounts	(4,192)
Balance, September 30, 2024	$37,056	~~37,056~~
Current period provisions	30,778
Write-offs charged against allowance	(24,631)

Filing Compare · ATMOS ENERGY CORP