MASTR Asset Backed Securities Trust 2004-FRE1
Mortgage Pass Through Certificates, Series 2004-FRE1

STATEMENT TO CERTIFICATEHOLDERS

Distribution Date:

08/25/04

		Original	Beginning				Allocated	Ending
		Certificate	Certificate	Principal	Interest	Total	Realized	Certificate
Class	Cusip	Face Value	Balance	Distribution	Distribution(1)	Distribution	Losses	Balance
A-1	57643LDR4	$276,076,000.00	$276,076,000.00	$10,206,977.90	$374,773.17	$10,581,751.07	$0.00	$265,869,022.10
A-2	57643LDS2	$122,267,000.00	$122,267,000.00	$4,488,074.39	$165,977.45	$4,654,051.84	$0.00	$117,778,925.61
A-IO	57643LDT0	$509,064,639.20	$509,064,639.20	N/A	$393,252.43	$393,252.43	$0.00	$494,369,586.91
M-1	57643LDU7	$19,854,000.00	$19,854,000.00	$0.00	$30,078.81	$30,078.81	$0.00	$19,854,000.00
M-2	57643LDV5	$13,999,000.00	$13,999,000.00	$0.00	$21,733.45	$21,733.45	$0.00	$13,999,000.00
M-3	57643LDW3	$11,454,000.00	$11,454,000.00	$0.00	$18,383.67	$18,383.67	$0.00	$11,454,000.00
M-4	57643LDX1	$10,181,000.00	$10,181,000.00	$0.00	$19,623.88	$19,623.88	$0.00	$10,181,000.00
M-5	57643LDY9	$8,909,000.00	$8,909,000.00	$0.00	$17,840.27	$17,840.27	$0.00	$8,909,000.00
M-6	57643LDZ6	$8,909,000.00	$8,909,000.00	$0.00	$19,176.62	$19,176.62	$0.00	$8,909,000.00
M-7	57643LEA0	$7,636,000.00	$7,636,000.00	$0.00	$18,727.29	$18,727.29	$0.00	$7,636,000.00
M-8	57643LEB8	$7,636,000.00	$7,636,000.00	$0.00	$19,586.34	$19,586.34	$0.00	$7,636,000.00
M-9	57643LEC6	$6,363,000.00	$6,363,000.00	$0.00	$23,718.08	$23,718.08	$0.00	$6,363,000.00
M-10	57643LED4	$5,091,000.00	$5,091,000.00	$0.00	$18,976.70	$18,976.70	$0.00	$5,091,000.00
CE	NA	$10,689,539.20	$10,689,539.20	$0.00	$1,659,773.10	$1,659,773.10	$0.00	$10,689,539.20
P	NA	$100.00	$100.00	$0.00	$271,890.35	$271,890.35	$0.00	$100.00
R-X	NA	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00	$0.00
Total		$509,064,639.20	$509,064,639.20	$14,695,052.29	$3,073,511.61	$17,768,563.90	$0.00	$494,369,586.91

AMOUNTS PER $1,000 UNIT						PASS THROUGH RATES
					Ending	Original	Current	Next
	Principal	Interest	Total	Realized	Certificate	Pass-Through	Pass-Through	Pass-Through
Class	Distribution	Distribution	Distribution	Losses	Balance	Interest Rate	Interest Rate	Interest Rate*
A-1	36.97162339	1.35750000	38.32912339	0.00000000	963.02837661	1.81000%	1.81000%	1.95500%
A-2	36.70716048	1.35749998	38.06466046	0.00000000	963.29283952	1.81000%	1.81000%	1.95500%
A-IO	N/A	0.77249999	0.77249999	0.00000000	971.13322915	1.03000%	1.03000%	0.88500%
M-1	0.00000000	1.51500000	1.51500000	0.00000000	1000.00000000	2.02000%	2.02000%	2.16500%
M-2	0.00000000	1.55250018	1.55250018	0.00000000	1000.00000000	2.07000%	2.07000%	2.21500%
M-3	0.00000000	1.60500000	1.60500000	0.00000000	1000.00000000	2.14000%	2.14000%	2.28500%
M-4	0.00000000	1.92750025	1.92750025	0.00000000	1000.00000000	2.57000%	2.57000%	2.71500%
M-5	0.00000000	2.00249972	2.00249972	0.00000000	1000.00000000	2.67000%	2.67000%	2.81500%
M-6	0.00000000	2.15249972	2.15249972	0.00000000	1000.00000000	2.87000%	2.87000%	3.01500%
M-7	0.00000000	2.45250000	2.45250000	0.00000000	1000.00000000	3.27000%	3.27000%	3.41500%
M-8	0.00000000	2.56500000	2.56500000	0.00000000	1000.00000000	3.42000%	3.42000%	3.56500%
M-9	0.00000000	3.72749961	3.72749961	0.00000000	1000.00000000	4.97000%	4.97000%	5.11500%
M-10	0.00000000	3.72749951	3.72749951	0.00000000	1000.00000000	4.97000%	4.97000%	5.11500%
CE	0.00000000	155.27078099	155.27078099	0.00000000	1000.00000000	3.91252%	3.91252%
P	0.00000000	2718903.5000	2718903.5000	0.00000000	1000.00000000
R-X	0.00000000	0.0000000	0.0000000	0.00000000	0.00000000
								* Estimated

(1) - The Class P Certificates do not accrue interest. Amounts appearing as Interest Distributions represent payments of Prepayment Charges.

	Please contact the Bondholder relations Department of U.S. Bank National Association at
	(800) 934-6802 with any questions regarding this statement or your distribution.

U.S. BANK NATIONAL ASSOCIATION

Page 1

MASTR Asset Backed Securities Trust 2004-FRE1
Mortgage Pass Through Certificates, Series 2004-FRE1

STATEMENT TO CERTIFICATEHOLDERS

Distribution Date:

08/25/04

Section 4.02 (i) - PREPAYMENT CHARGES
	For Allocation of Principal, SEE PAGE 1
	Prepayment Charges allocated to Class P	271,890.35
	Servicer Prepayment Charge Payment Amounts allocated to Class P	$0.00

Section 4.02 (ii) and (xv) - INTEREST

		Monthly		Remaining	Reduction from the Allocation of:
	Interest	Interest	Interest	Unpaid		Prepayment	Relief Act
	Distribution	Distributable	Shortfall	Interest	Realized	Interest	Interest
Class	Amount	Amount	Amount	Amount	Losses	Shortfalls	Shortfalls
A-1	$374,773.17	$374,773.17	$0.00	$0.00	$0.00	$0.00	$0.00
A-2	$165,977.45	$165,977.45	$0.00	$0.00	$0.00	$0.00	$0.00
A-IO	$393,252.43	$393,252.43	$0.00	$0.00	$0.00	$0.00	$0.00
M-1	$30,078.81	$30,078.81	$0.00	$0.00	$0.00	$0.00	$0.00
M-2	$21,733.45	$21,733.45	$0.00	$0.00	$0.00	$0.00	$0.00
M-3	$18,383.67	$18,383.67	$0.00	$0.00	$0.00	$0.00	$0.00
M-4	$19,623.88	$19,623.88	$0.00	$0.00	$0.00	$0.00	$0.00
M-5	$17,840.27	$17,840.27	$0.00	$0.00	$0.00	$0.00	$0.00
M-6	$19,176.62	$19,176.62	$0.00	$0.00	$0.00	$0.00	$0.00
M-7	$18,727.29	$18,727.29	$0.00	$0.00	$0.00	$0.00	$0.00
M-8	$19,586.34	$19,586.34	$0.00	$0.00	$0.00	$0.00	$0.00
M-9	$23,718.08	$23,718.08	$0.00	$0.00	$0.00	$0.00	$0.00
M-10	$18,976.70	$18,976.70	$0.00	$0.00	$0.00	$0.00	$0.00
CE	$1,659,773.10	1,659,773.10	$0.00	$0.00	$0.00	$0.00	$0.00
P	$271,890.35	N/A	N/A	N/A	$0.00	$0.00	$0.00
Total	$3,073,511.61	$2,801,621.26	$0.00	$0.00	$0.00	$0.00	$0.00

Section 4.02 (iii), (xii) - FEES
	Servicing Fee (and any additional Servicer compensation)	$212,110.45
	Trustee Fee	$9,969.18
	Credit Risk Manager Fee	$6,363.31
	Extraordinary Trust Fund Expenses	$0.00

Section 4.02 (iv) - ADVANCES
		Aggregate Advances for the Collection Period					$99,784.47

Section 4.02 (v) - POOL
	Stated Principal Balance of Mortgage Loans and any REO Properties	$494,369,586.91
	Number of Mortgage Loans and any REO Properties	2,774

Section 4.02 (vi) - LOANS
	Number of Mortgage Loans	2,774
	Stated Principal Balance of Mortgage Loans	$494,369,586.91
	Weighted Average Remaining Term to Maturity	347
	Weighted Average Mortgage Interest Rate	7.1427%

Section 4.02 (vii) - DELINQUENCIES

			Stated Principal	Stated Principal
	Number	Number as %	Balance	Balance as %
30-59 days delinquent	53	1.91060%	$8,441,022.01	1.70743%
60-89 days delinquent	23	0.82913%	$3,448,986.18	0.69765%
90 or more days delinquent	1	0.03605%	$340,120.75	0.06880%
Foreclosures	0	0.00000%	$0.00	0.00000%
Bankruptcies	0	0.00000%	$0.00	0.00000%

Section 4.02 (viii) - REO
	Number of REO Loans	0
	Number of REO Loans as %	0.00000%
	Stated Principal Balance of REO Properties	$0.00
	Stated Principal Balance of REO Properties as %	0.00000%

Page 2

MASTR Asset Backed Securities Trust 2004-FRE1
Mortgage Pass Through Certificates, Series 2004-FRE1

STATEMENT TO CERTIFICATEHOLDERS

Distribution Date:

08/25/04

Section 4.02 (x), (xxiii) - AVAILABLE FUNDS
	Principal:
	Scheduled Principal	$369,803.02
	Principal Prepayments (includes curtailments)	$14,325,249.27
	Liquidation Proceeds	$0.00
	Total Principal	$14,695,052.29
	Net Interest (net of servicing & trustee fee)	$2,801,621.26
	Available Funds (total principal plus net interest)	$17,496,673.55

Section 4.02 (xi) - LOSSES
	Current Realized Losses	$0.00
	Aggregate Realized Losses	$0.00
	Subsequent Recoveries	$0.00
	Aggregate Subsequent Recoveries	$0.00

Section 4.02 (xiii), (xiv) - BALANCES
		For Certificate Balances and Loss Allocations, SEE PAGE 1

Section 4.02 (xviii)
	Overcollateralization Target Amount	$10,689,539.20
	Overcollateralized Amount	$10,689,639.20
	Overcollateralization Deficiency	$0.00
	Overcollateralization Release Amount	$0.00
	Credit Enhancement Percentage	22.397%

Section 4.02 (xx)
	Aggregate Realized Losses	$0.00
	Aggregate Balance of Liquidated Loans	$0.00
	Aggregate Loss Severity Percentage	0.00000%

Section 4.02 (xxi)
	Stepdown Date Occurrence	NO
	Trigger Event Occurrence	NO

Section 4.02 (xxiii) - NET WAC RATE CARRYOVER AMOUNTS

	Net WAC Rate	Cap Contract	Amounts
Class	Carryover Amount	Payment Amount	Unpaid
A-1	$0.00	$0.00	$0.00
A-2	$0.00	$0.00	$0.00
M-1	$0.00	$0.00	$0.00
M-2	$0.00	$0.00	$0.00
M-3	$0.00	$0.00	$0.00
M-4	$0.00	$0.00	$0.00
M-5	$0.00	$0.00	$0.00
M-6	$0.00	$0.00	$0.00
M-7	$0.00	$0.00	$0.00
M-8	$0.00	$0.00	$0.00
M-9	$0.00	$0.00	$0.00
M-10	$0.00	$0.00	$0.00

Section 4.02 (xxiv) - PAYMENTS MADE UNDER CAP CONTRACTS
	A-1 Cap Contract	0.00
	A-2 Cap Contract	0.00
	Mezzanine Contract	0.00

Page 3

MASTR Asset Backed Securities Trust 2004-FRE1
Mortgage Pass Through Certificates, Series 2004-FRE1

STATEMENT TO CERTIFICATEHOLDERS

Distribution Date:

08/25/04

Section 4.02 (xiv) - ENDING BALANCE FACTORS

			Class	Factor
			A-1	0.963028
			A-2	0.963293
			M-1	1.000000
			M-2	1.000000
			M-3	1.000000
			M-4	1.000000
			M-5	1.000000
			M-6	1.000000
			M-7	1.000000
			M-8	1.000000
			M-9	1.000000
			M-10	1.000000
			CE	1.000000
			P	1.000000

Page 4

MASTR ASSET BACKED SECURITIES TRUST 2004-FRE1 8-K