Summary of Significant Accounting Policies (Policies)	12 Months Ended
Summary of Significant Accounting Policies (Policies)	Dec. 31, 2025
Accounting Policies [Abstract]
Cash and Cash Equivalents	Cash and Cash Equivalents The Company considers all highly liquid investments with original maturities of three months or less to be cash equivalents. At times, cash and cash equivalent balances may exceed federally insured limits. Management believes that the Company mitigates any risks by depositing cash and investing in cash equivalents with major financial institutions.
Insurance	Insurance The Company is subject to medical malpractice and other lawsuits due to the nature of the services the Company provides. A portion of the Company’s professional liability risks are insured through a wholly-owned insurance subsidiary providing coverage for up to $10.0 million per claim, $15.0 million for certain other claims and $25.0 million for certain batched claims through August 31, 2025 and $15.0 million per claim and $25.0 million for certain batched claims thereafter. The Company has obtained reinsurance coverage from a third-party to cover claims in excess of those limits. The reinsurance policy has a coverage limit of $80.0 million or $75.0 million in the aggregate for certain other claims through August 31, 2025 and $75.0 million in the aggregate for claims thereafter, with exclusions for certain types of incidents. The Company’s reinsurance receivables are recognized consistent with the related liabilities and include known claims and any incurred but not reported claims that are covered by current insurance policies in place. The reserve for professional and general liability risks was estimated based on historical claims, prior settlements and judgments, industry trends, severity factors, and other actuarial assumptions. The estimated accrual for professional and general liabilities could be significantly affected should current and future occurrences differ from historical claim trends and expectations. While claims are monitored closely when estimating professional and general liability accruals, the complexity of the claims and wide range of potential outcomes often hampers timely adjustments to the assumptions used in these estimates. The Company recorded unfavorable adjustments of $52.7 million and $10.1 million to its estimated liability for self-insured professional and general liability claims during the years ended December 31, 2025 and 2024, respectively, relating to the settlement or expected settlement of certain prior year claims. In particular, the unfavorable adjustment recorded during the year ended December 31, 2025 was driven by higher expected settlement costs for claims related to policy years prior to September 1, 2024; a significant increase in claim frequency during the policy year ended August 31, 2025, compared to the prior policy year; and less favorable insurance coverage terms compared to prior years. The professional and general liability reserve was $181.8 million at December 31, 2025, of which $31.4 million was included in other accrued liabilities and $150.4 million was included in other long-term liabilities. The professional and general liability reserve was $87.5 million at December 31, 2024, of which $12.5 million was included in other accrued liabilities and $75.0 million was included in other long-term liabilities. The Company estimates receivables for the portion of professional and general liability reserves that are recoverable under the Company’s insurance policies. Such receivable was $28.8 million at December 31, 2025, of which $7.2 million was included in other current assets and $21.6 million was included in other assets, and such receivable was $9.3 million at December 31, 2024, of which $0.5 million was included in other current assets and $8.8 million was included in other assets. The Company’s statutory workers’ compensation program is fully insured with a $0.5 million deductible per accident. The workers’ compensation liability was $34.3 million at December 31, 2025, of which $18.5 million was included in accrued salaries and benefits and $15.8 million was included in other long-term liabilities, and such liability was $30.7 million at December 31, 2024, of which $12.0 million was included in accrued salaries and benefits and $18.7 million was included in other long-term liabilities. The reserve for workers compensation claims was based upon independent actuarial estimates of future amounts that will be paid to claimants. Management believes that adequate provisions have been made for workers’ compensation and professional and general liability risk exposures.
Property and Equipment and Other Long-Lived Assets	Property and Equipment and Other Long-Lived Assets Property and equipment are recorded at cost. Depreciation is calculated on the straight-line basis over the estimated useful lives of the assets, which typically range from 10 to 50 years for buildings and improvements, three to seven years for equipment and the shorter of the lease term or estimated useful lives for leasehold improvements. When assets are sold or retired, the corresponding cost and accumulated depreciation are removed from the related accounts and any gain or loss is recorded in the period of sale or retirement. Repair and maintenance costs are expensed as incurred. Depreciation expense was $189.2 million, $149.6 million and $132.3 million for the years ended December 31, 2025, 2024 and 2023, respectively. The carrying values of long-lived assets are reviewed for possible impairment whenever events, circumstances or operating results indicate that the carrying amount of an asset may not be recoverable. If this review indicates that the asset will not be recoverable, as determined based upon the undiscounted cash flows of the operating asset over the remaining useful life, the carrying value of the asset will be reduced to its estimated fair value. Fair value estimates are based on independent appraisals, market values of comparable assets or internal evaluations of future net cash flows. During the years ended December 31, 2025 and 2024, the Company recorded non-cash property impairment charges of $10.4 million and $12.4 million, respectively, and non-cash operating lease right-of-use asset impairment charges of $1.0 million and $1.4 million, respectively, related to the closure of certain facilities, which is included in loss on impairment in the consolidated statements of operations. The Company performed an impairment review of long-lived assets in the fourth quarter of 2025, 2024 and 2023 and recorded no impairment.
Goodwill and Indefinite-Lived Intangible Assets	Goodwill and Indefinite-Lived Intangible Assets The Company’s goodwill and other indefinite-lived intangible assets, which consist of licenses and accreditations, trade names and certificates of need intangible assets that are not amortized, are evaluated for impairment annually during the fourth quarter or more frequently if events indicate the carrying value of a reporting unit may not be recoverable. See Note 5 – Acquisitions and Note 8 – Other Intangible Assets for further discussion of the Company’s goodwill and other intangible assets, respectively.
Stock Compensation	Stock Compensation The Company measures and recognizes the cost of employee services received in exchange for awards of equity instruments based on the grant-date fair value in accordance with the Financial Accounting Standards Board (the “FASB”) Accounting Standards Codification (“ASC”) 718, “ Compensation — Stock Compensation.” The Company uses the Black-Scholes valuation model to determine grant-date fair value for stock options and recognizes straight-line amortization of share-based compensation expense over the requisite service period of the respective awards. The fair values of performance stock units are determined based on the closing price of the Company’s common stock on the trading date immediately prior to the grant date for units subject to performance conditions.
Earnings Per Share	Earnings Per Share Basic and diluted earnings per share are calculated in accordance with FASB ASC 260, “Earnings Per Share,” based on the weighted-average number of shares outstanding in each period and dilutive stock options and non-vested shares, to the extent such securities have a dilutive effect on earnings per share.
Income Taxes	Income Taxes The Company uses the asset and liability method of accounting for income taxes. Under this method, deferred income taxes reflect the net tax effects of temporary differences between the carrying amounts of assets and liabilities for financial reporting purposes and the amounts used for income tax purposes and net operating loss and tax credit carryforwards. The amount of deferred taxes on these temporary differences is determined using the tax rates that are expected to apply in the period when the asset is realized or the liability is settled, as applicable, based on tax rates and laws in the respective tax jurisdiction enacted as of the balance sheet date. The Company reviews its deferred tax assets for recoverability and establishes a valuation allowance based on historical taxable income, projected future taxable income, applicable tax strategies, and the expected timing of the reversals of existing temporary differences. A valuation allowance is provided when it is more likely than not that some portion or all of the deferred tax assets will not be realized. The Company records a liability for unrecognized tax benefits resulting from uncertain tax positions taken or expected to be taken in a tax return. The Company recognizes interest and penalties, if any, related to unrecognized tax benefits in income tax expense. The Company has accruals for taxes and associated interest that may become payable in future years as a result of audits by tax authorities. The Company accrues for tax contingencies when it is more likely than not that a liability to a taxing authority has been incurred and the amount of the contingency can be reasonably estimated. Although management believes that the positions taken on previously filed tax returns are reasonable, the Company nevertheless has established tax and interest reserves in recognition that various taxing authorities may challenge the positions taken by the Company resulting in additional liabilities for taxes and interest. These amounts are reviewed as circumstances warrant and adjusted as events occur that affect the Company’s potential liability for additional taxes, such as lapsing of applicable statutes of limitations, conclusion of tax audits, additional exposure based on current calculations, identification of new issues, release of administrative guidance, or rendering of a court decision affecting a particular tax issue.
Recent Accounting Pronouncements	Recent Accounting Pronouncements In August 2023, the FASB issued Accounting Standards Update (“ASU”) 2023-05 Business Combinations—Joint Venture Formations (Subtopic 805-60): “Recognition and Initial Measurement” (“ASU 2023-05”). ASU 2023-05 requires entities to recognize and initially measure a joint venture’s assets and liabilities at fair value on the formation date. This guidance is effective prospectively for all joint ventures formed on or after January 1, 2025, and may be applied either prospectively or retrospectively. The Company prospectively adopted ASU 2023-05 on January 1, 2025, and such adoption did not have a significant impact on the Company’s consolidated financial statements. In November 2023, the FASB issued ASU 2023-07 Segment Reporting (Topic 280): “Improvements to Reportable Segment Disclosures” (“ASU 2023-07”). ASU 2023-07 is intended to improve reportable segment disclosure requirements, primarily through enhanced disclosures about significant segment expenses. This guidance is effective for fiscal years beginning after December 15, 2023, and the interim periods within the fiscal years beginning after December 15, 2024, with early adoption permitted and applied retrospectively. The Company adopted ASU 2023-07 for the year ended December 31, 2024. See Note 22 — Segments for additional information on the Company’s accounting for segment reporting. This adoption did not have a significant impact on the Company’s consolidated financial statements. In December 2023, the FASB issued ASU 2023-09 Income Taxes (Topic 740): “Improvements to Income Tax Disclosures Topic 740.” (“ASU 2023-09”). ASU 2023-09 is intended to enhance the transparency and decision usefulness of income tax disclosures. This guidance is effective for fiscal years beginning after December 15, 2024, with early adoption permitted, and may be applied either prospectively or retrospectively. The Company adopted this standard on a prospective basis for the year ended December 31, 2025. See Note 19 – Income Taxes for additional information. In November 2024, the FASB issued ASU 2024-03 Income Statement—Reporting Comprehensive Income—Expense Disaggregation Disclosures (Subtopic 220-40): “Disaggregation of Income Statement Expenses” (“ASU 2024-03”). ASU 2024-03 requires disaggregated disclosure of certain income statement expenses. This guidance is effective for fiscal years beginning after December 15, 2026 and interim periods within fiscal years beginning after December 15, 2027. Early adoption is permitted and must be applied prospectively. The Company is currently evaluating the impact of ASU 2023-09 on the Company’s consolidated financial statements. In July 2025, the FASB issued ASU 2025-05 Financial Instruments—Credit Losses (Topic 326): “Measurement of Credit losses for Accounts Receivable and Contract Assets” (“ASU 2025-05”). ASU 2025-05 allows entities to elect a practical expedient to assume the current conditions as of the balance sheet date remain unchanged for the remaining life of the asset in the development of a reasonable and supportable forecast for current accounts receivable and current contract assets arising from transactions accounted for under ASC 606, Revenue from Contracts with Customers. This guidance is effective for fiscal years beginning after December 15, 2025, and interim reporting periods within those fiscal years, and must be adopted prospectively. Early adoption is permitted and must be applied as of the beginning of the annual reporting period in which it is early adopted. The Company is currently evaluating the impact of ASU 2025-05 on the Company’s consolidated financial statements. In September 2025, the FASB issued ASU 2025-06 Intangibles—Goodwill and Other—Internal-Use Software (Subtopic 350-40): “Targeted Improvements to the Accounting for Internal-Use Software” (“ASU 2025-06”). ASU 2025-06 is intended to clarify and modernize the accounting for costs related to internal-use software. This guidance is effective for fiscal years beginning after December 15, 2027, and interim periods within those fiscal years, and may be adopted using a prospective, retrospective, or modified transition approach. Early adoption is permitted and must be applied as of the beginning of the annual reporting period in which it is early adopted. The Company is currently evaluating the impact of ASU 2025-06 on the Company’s consolidated financial statements. In December 2025, the FASB issued ASU 2025-10 Government Grants (Topic 832): “Accounting for Government Grants Received by Business Entities” (“ASU 2025-10”). ASU 2025-10 establishes guidance on the recognition, measurement, and presentation of government grants received by business entities. This guidance leverages the principles in the accounting framework for government assistance in International Accounting Standard 20, Accounting for Government Grants and Disclosure of Government Assistance (“IAS 20”), makes certain targeted improvements, and modifies certain of the existing disclosure requirements in ASC 832, Government Assistance. ASU 2025-10 is effective for fiscal years beginning after December 15, 2028, and interim reporting periods within those fiscal years, and may be adopted on a modified prospective basis, a modified retrospective basis, or a full retrospective basis. Early adoption is permitted in any period for which financial statements have not been issued. The Company is currently evaluating the impact of ASU 2025-06 on the Company’s consolidated financial statements. In December 2025, the FASB issued ASU 2025-11 Interim Reporting (Topic 270): “Narrow-Scope Improvements” (“ASU 2025-11”). ASU 2025-11 clarifies the interim reporting requirements in GAAP by improving the navigability of Topic 270 and more clearly specifying what disclosures are required in an interim reporting period. This guidance is effective for interim reporting periods in fiscal years beginning after December 15, 2027, and may be adopted on a prospective or retrospective basis. Early adoption is permitted. The Company is currently evaluating the impact of ASU 2025-11 on the Company’s consolidated financial statements. In December 2025, the FASB issued ASU 2025-12 Codification Improvements (“ASU 2025-12”). ASU 2025-12 provides for technical corrections, clarifications and other minor improvements to a variety of Topics. This guidance is effective for annual reporting periods beginning after December 15, 2026, and interim reporting periods within those annual reporting periods and may be adopted on a prospective or retrospective basis on an issue-by-issue basis. Early adoption is permitted on an issue-by-issue basis. The Company is currently evaluating the impact of ASU 2025-12 on the Company’s consolidated financial statements.

Disclosure of accounting policy for income taxes, which may include its accounting policies for recognizing and measuring deferred tax assets and liabilities and related valuation allowances, recognizing investment tax credits, operating loss carryforwards, tax credit carryforwards, and other carryforwards, methodologies for determining its effective income tax rate and the characterization of interest and penalties in the financial statements.

- Definition

Disclosure of accounting policy for award under share-based payment arrangement. Includes, but is not limited to, methodology and assumption used in measuring cost.

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+ Details

Acadia Healthcare Company, Inc. 10-K