~~Delaware~~UNITED ~~333-102888~~STATES 95SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-~~4791925~~K Current Report Pursuant To Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): (Date of earliest event reported) Indymac MBS Inc (as Depositor under the Pooling and Servicing Agreement, dated as April 1, 2004, providing for the issuance of Residential Asset Securitization Trust Series 2004-~~-------------------------------------~~A3 Mortgage Pass-~~----------~~Through Certificates, Series 2004-~~---------------~~C) (Exact name of registrant as specified in charter) DELAWARE (State or Other Jurisdiction of Incorporation) 333-102888-20 95-4791925 (Commission File Number) (I.R.S. Employer Identification No.) 155 NORTH LAKE AVENUE PASADENA, CALIFORNIA 91101 (Address of ~~Incorporation~~principal executive offices) ~~File~~(Zip Code) Registrant's Telephone Number, Including Area Code: (800) ~~Identification~~669-2300 No(Former name or former address, if changed since last report.) ~~155~~Check ~~North~~the ~~Lake~~appropriate ~~Avenue~~box ~~Pasadena,~~below ~~California~~if ~~91101~~the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions (see General Instruction A.2. below): [ ] Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425) [ ] Soliciting material pursuant to Rule 14a-12(b) under the Exchange Act (17 CFR 240.14a-12(b)) [ ] Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-~~--------------~~2(b)) [ ] Pre-~~-------~~commencement communications pursuant to Rule 13e-4(~~Address~~c) ofunder ~~Principal~~the Exchange Act (~~Zip~~17 ~~Code~~CFR 240.13e-4(c)) ~~Executive~~Item ~~Offices~~8.01 Other Events Attached hereto is a copy of the Monthly Remittance Statements to the Certificateholders which was derived from the monthly information submitted by the Master Servicer of the Trust to the Trustee. Item 9.01 Financial Statements and Exhibits (c) Exhibits: Exhibit No. Description 99.1 Monthly Remittance Statement to the Certificateholders dated as of . Signatures Pursuant to the requirements of the Securities Exchange Act of 1934, the Registrant has duly caused this report to be signed on its behalf by the undersigned, hereunto duly authorized. Deutsche Bank National Trust Company, in its capacity as Trustee under the Pooling and Servicing Agreement on behalf of Indymac MBS Inc, Registrant Date: Sep 27, 2004 By: /s/ Katherine M. Wannenmacher Katherine M. Wannenmacher Vice President EXHIBIT INDEX DOCUMENT 99.1 Monthly Remittance Statement to the Certificateholders dated as of .



IndyMac Residential Asset Securitization Trust 2004-A3

Mortgage Pass-Through Certificates
Mortgage Pass-Through Certificates
REMIC 2004-A3

September 27, 2004 Distribution

				External Parties					Table of Contents

												Page
				Seller								Page
				Seller					1. Certificate Payment Report					2
				IndyMac Bank					1. Certificate Payment Report					2
				IndyMac Bank					2. Collection Account Report					4
									2. Collection Account Report					4
									3. Credit Enhancement Report					6
									4. Collateral Report					7
				Certificate Insurer(s)					5. Delinquency Report					10
				Certificate Insurer(s)					5. Delinquency Report					10
									6. REO Report					11

									7. Foreclosure Report					12
									8. Prepayment Report					13
									9. Prepayment Detail Report					16
									9. Prepayment Detail Report					16
									10. Realized Loss Report					17
									11. Realized Loss Detail Report					20
				Servicer(s)					11. Realized Loss Detail Report					20
				Servicer(s)					12. Triggers and Adj. Cert. Report					21
				IndyMac Bank					12. Triggers and Adj. Cert. Report					21
				IndyMac Bank					13. Other Related Information					22
									13. Other Related Information					22


				Underwriter(s)
				Bear, Stearns & Co. Inc


									Total Number of Pages					22
									Total Number of Pages

				Dates					Contacts

				Cut-Off Date:		April 01, 2004			Brent Hoyler
				Close Date:		April 29, 2004			Administrator
				First Distribution Date:		May 25, 2004			(714) 247-6322
									Brent.Hoyler@db.com
									Brent.Hoyler@db.com
									Address:
									1761 East St. Andrew Place, Santa Ana, CA 92705
				Distribution Date:		September 27, 2004
									Factor Information:			(800) 735-7777
				Record Date:		August 31, 2004			Factor Information:			(800) 735-7777
									Main Phone Number:			(714) 247-6000
									Main Phone Number:			(714) 247-6000

									https://www.corporatetrust.db.com/invr



Page 1 of 22
IndyMac Residential Asset Securitization Trust 2004-A3

Mortgage Pass-Through Certificates
Mortgage Pass-Through Certificates
REMIC 2004-A3

September 27, 2004 Distribution
Certificate Payment Report
Current Period Distribution -
					Prior											Current
	Class		Original		Principal					Total		Realized		Deferred		Principal
	Class		Original		Principal					Total		Realized		Deferred		Principal
Class	Type	Cur	Face Value		Balance	Interest		Principal		Distribution		Loss		Interest		Balance


					(1)	(2)		(3)		(4)=(2)+(3)		(5)		(6)		(7)=(1)-(3)-(5)+(6)

A-1	PAC/SR	$	106,813,929.00		100,855,581.66	378,208.43		1,821,125.54		2,199,333.97		0.00		0.00		99,034,456.12
A-1	PAC/SR	$	106,813,929.00		100,855,581.66	378,208.43		1,821,125.54		2,199,333.97		0.00		0.00		99,034,456.12
A-2	PAC/SR	$	29,131,071.00		27,506,067.22	45,041.19		496,670.59		541,711.78		0.00		0.00		27,009,396.63
A-3	INV/NTL	$	0.00		0.00	138,332.60		0.00		138,332.60		0.00		0.00		0.00
A-4	TAC/SR	$	73,048,000.00		72,252,175.55	316,103.27		2,999,470.77		3,315,574.04		0.00		0.00		69,252,704.78
A-5	SR	$	5,753,000.00		2,657,177.87	11,625.15		745,227.02		756,852.17		0.00		0.00		1,911,950.85
A-6	SR	$	3,000,000.00		3,000,000.00	13,125.00		0.00		13,125.00		0.00		0.00		3,000,000.00
A-7	SR	$	25,512,000.00		25,512,000.00	111,615.00		0.00		111,615.00		0.00		0.00		25,512,000.00
PO	PO,RSTP	$	385,093.00		382,762.26	0.00		25,125.00		25,125.00		0.00		0.00		357,637.26
A-X	SR/NTL	$	0.00		0.00	92,467.10		0.00		92,467.10		0.00		0.00		0.00
A-R	SR/RES	$	100.00		0.00	0.00		0.00		0.00		0.00		0.00		0.00
B-1	SUB	$	6,122,000.00		6,096,991.59	26,674.34		53,810.42		80,484.76		0.00		0.00		6,043,181.17
B-2	SUB	$	1,786,000.00		1,778,704.18	7,781.83		15,698.37		23,480.20		0.00		0.00		1,763,005.81
B-3	SUB	$	1,276,000.00		1,270,787.52	5,559.70		11,215.63		16,775.33		0.00		0.00		1,259,571.89
B-4	SUB/NOF	$	893,000.00		889,352.08	3,890.92		7,849.18		11,740.10		0.00		0.00		881,502.90
B-5	SUB/NOF	$	383,000.00		381,435.44	1,668.78		3,366.45		5,035.23		0.00		0.00		378,068.99
B-6	SUB/NOF	$	1,020,571.00		1,016,401.99	4,446.76		8,970.49		13,417.25		0.00		0.00		1,007,431.50
P	NOF	$	100.00		100.00	4,766.72		0.00		4,766.72		0.00		0.00		100.00

Total			255,123,864.00		243,599,537.36	1,161,306.79		6,188,529.46		7,349,836.25		0.00		0.00		237,411,007.90
Total




Interest Accrual Detail Current Period Factor Information per $1,0000 of Original Face-
								Orig. Principal		Prior							Current
								Orig. Principal		Prior							Current
	Period		Period					(with Notional)		Principal						Total	Principal
	Period		Period
Class	Starting		Ending		Method	Cusip		Balance		Balance		Interest		Principal		Distribution	Balance

								(1)		(1)		(2)		(3)		(4)=(2)+(3)	(5)
A-1	08/01/04		08/30/04		F-30/360	45660NE92		106,813,929.00		944.217506		3.540816		17.049514		20.590329	927.167992
A-2	08/25/04		09/24/04		A-30/360	45660NF26		29,131,071.00		944.217506		1.546156		17.049514		18.595670	927.167993
A-3	08/25/04		09/24/04		A-30/360	45660NF34		29,131,071.00		944.217506		4.748627		0.000000		4.748627	927.167993
A-4	08/01/04		08/30/04		F-30/360	45660NF42		73,048,000.00		989.105459		4.327336		41.061641		45.388978	948.043817
A-5	08/01/04		08/30/04		F-30/360	45660NF59		5,753,000.00		461.876911		2.020711		129.537115		131.557825	332.339797
A-6	08/01/04		08/30/04		F-30/360	45660NF67		3,000,000.00		1,000.000000		4.375000		0.000000		4.375000	1,000.000000
A-7	08/01/04		08/30/04		F-30/360	45660NF75		25,512,000.00		1,000.000000		4.375000		0.000000		4.375000	1,000.000000
PO	08/01/04		08/30/04		F-30/360	45660NF83		385,093.00		993.947592		0.000000		65.243980		65.243980	928.703612
A-X	08/01/04		08/30/04		F-30/360	45660NF91		235,616,408.78		951.505491		0.392448		0.000000		0.392448	927.453129
A-R	08/01/04		08/30/04		F-30/360	45660NG25		100.00		0.000000		0.000000		0.000000		0.000000	0.000000
B-1	08/01/04		08/30/04		F-30/360	45660NG33		6,122,000.00		995.914993		4.357128		8.789680		13.146808	987.125314
B-2	08/01/04		08/30/04		F-30/360	45660NG41		1,786,000.00		995.914994		4.357128		8.789681		13.146809	987.125314
B-3	08/01/04		08/30/04		F-30/360	45660NG58		1,276,000.00		995.914984		4.357132		8.789679		13.146810	987.125306
B-4	08/01/04		08/30/04		F-30/360			893,000.00		995.914983		4.357133		8.789675		13.146809	987.125308
B-5	08/01/04		08/30/04		F-30/360			383,000.00		995.914987		4.357128		8.789687		13.146815	987.125300
B-6	08/01/04		08/30/04		F-30/360			1,020,571.00		995.915022		4.357129		8.789678		13.146807	987.125345
P	08/01/04		08/30/04		30/360			100.00		1,000.000000		47,667.200000		0.000000		47,667.200000	1,000.000000



Page 2 of 22
IndyMac Residential Asset Securitization Trust 2004-A3

Mortgage Pass-Through Certificates
Mortgage Pass-Through Certificates
REMIC 2004-A3

September 27, 2004 Distribution

Distribution to Date -
																Current


	Original				Unscheduled	Scheduled		Total		Total		Realized		Deferred		Principal

Class	Face Value		Interest		Principal	Principal		Principal		Distribution		Loss		Interest		Balance
	(1)		(2)		(3)	(4)		(5)=(3)+(4)		(6)=(2)+(5)		(7)		(8)		(9)=(1)-(5)-(7)+(8)
A-1	106,813,929.00		1,948,054.86		6,557,363.01	1,222,109.87		7,779,472.88		9,727,527.74		0.00		0.00		99,034,456.12
A-2	29,131,071.00		195,652.71		1,788,371.69	333,302.68		2,121,674.37		2,317,327.08		0.00		0.00		27,009,396.63
A-3	0.00		748,858.74		0.00	0.00		0.00		748,858.74		0.00		0.00		0.00
A-4	73,048,000.00		1,586,279.63		2,732,628.67	1,062,666.55		3,795,295.22		5,381,574.85		0.00		0.00		69,252,704.78
A-5	5,753,000.00		84,233.17		3,438,086.65	402,962.50		3,841,049.15		3,925,282.32		0.00		0.00		1,911,950.85
A-6	3,000,000.00		65,625.00		0.00	0.00		0.00		65,625.00		0.00		0.00		3,000,000.00
A-7	25,512,000.00		558,075.00		0.00	0.00		0.00		558,075.00		0.00		0.00		25,512,000.00
PO	385,093.00		0.00		25,217.79	2,237.95		27,455.74		27,455.74		0.00		0.00		357,637.26
A-X	0.00		483,103.28		0.00	0.00		0.00		483,103.28		0.00		0.00		0.00
A-R	100.00		0.44		0.00	100.00		100.00		100.44		0.00		0.00		0.00
B-1	6,122,000.00		133,646.08		0.00	78,818.83		78,818.83		212,464.91		0.00		0.00		6,043,181.17
B-2	1,786,000.00		38,989.20		0.00	22,994.19		22,994.19		61,983.39		0.00		0.00		1,763,005.81
B-3	1,276,000.00		27,855.67		0.00	16,428.11		16,428.11		44,283.78		0.00		0.00		1,259,571.89
B-4	893,000.00		19,494.61		0.00	11,497.10		11,497.10		30,991.71		0.00		0.00		881,502.90
B-5	383,000.00		8,361.07		0.00	4,931.01		4,931.01		13,292.08		0.00		0.00		378,068.99
B-6	1,020,571.00		22,279.54		0.00	13,139.50		13,139.50		35,419.04		0.00		0.00		1,007,431.50
P	100.00		9,671.09		0.00	0.00		0.00		9,671.09		0.00		0.00		100.00

Total	255,123,864.00		5,930,180.09		14,541,667.81	3,171,188.29		17,712,856.10		23,643,036.19		0.00		0.00		237,411,007.90


Interest Detail -
	Pass		Prior Principal			Non-		Prior		Unscheduled				Paid or		Current
	Pass		Prior Principal			Non-		Prior		Unscheduled				Paid or

	Through		(with Notional)		Accrued	Supported		Unpaid		Interest		Optimal		Deferred		Unpaid

Class	Rate		Balance		Interest	Interest SF		Interest		Adjustment		Interest		Interest		Interest
					(1)	(2)		(3)		(4)		(5)=(1)-(2)+(3)+(4)		(6)		(7)=(5)-(6)
A-1	4.50000%		100,855,581.66		378,208.43	0.00		0.00		0.00		378,208.43		378,208.43		0.00
A-2	1.96500%		27,506,067.22		45,041.19	0.00		0.00		0.00		45,041.19		45,041.19		0.00
A-3	6.03500%		27,506,067.22		138,332.60	0.00		0.00		0.00		138,332.60		138,332.60		0.00
A-4	5.25000%		72,252,175.55		316,103.27	0.00		0.00		0.00		316,103.27		316,103.27		0.00
A-5	5.25000%		2,657,177.87		11,625.15	0.00		0.00		0.00		11,625.15		11,625.15		0.00
A-6	5.25000%		3,000,000.00		13,125.00	0.00		0.00		0.00		13,125.00		13,125.00		0.00
A-7	5.25000%		25,512,000.00		111,615.00	0.00		0.00		0.00		111,615.00		111,615.00		0.00
PO	0.00000%		382,762.26		0.00	0.00		0.00		0.00		0.00		0.00		0.00
A-X	0.49494%		224,190,306.75		92,467.10	0.00		0.00		0.00		92,467.10		92,467.10		0.00
A-R	0.00000%		0.00		0.00	0.00		0.00		0.00		0.00		0.00		0.00
B-1	5.25000%		6,096,991.59		26,674.34	0.00		0.00		0.00		26,674.34		26,674.34		0.00
B-2	5.25000%		1,778,704.18		7,781.83	0.00		0.00		0.00		7,781.83		7,781.83		0.00
B-3	5.25000%		1,270,787.52		5,559.70	0.00		0.00		0.00		5,559.70		5,559.70		0.00
B-4	5.25000%		889,352.08		3,890.92	0.00		0.00		0.00		3,890.92		3,890.92		0.00
B-5	5.25000%		381,435.44		1,668.78	0.00		0.00		0.00		1,668.78		1,668.78		0.00
B-6	5.25000%		1,016,401.99		4,446.76	0.00		0.00		0.00		4,446.76		4,446.76		0.00
P	0.00000%		100.00		0.00	0.00		0.00		0.00		0.00		4,766.72		0.00

Total			495,295,911.33		1,156,540.07	0.00		0.00		0.00		1,156,540.07		1,161,306.79		0.00



Page 3 of 22
IndyMac Residential Asset Securitization Trust 2004-A3

Mortgage Pass-Through Certificates
Mortgage Pass-Through Certificates
REMIC 2004-A3

September 27, 2004 Distribution
Collection Account Report
SUMMARY
SUMMARY
													Total
Principal Collections													6,188,529.46
Principal Withrawals													0.00
Principal Other Accounts													0.00
TOTAL NET PRINCIPAL													6,188,529.46
Interest Collections													1,174,191.60
Interest Withdrawals													-0.00
Interest Other Accounts													4,766.72
Interest Fees													-17,651.53
TOTAL NET INTEREST													1,161,306.79
TOTAL AVAILABLE FUNDS FOR DISTRIBUTION													7,349,836.25



PRINCIPAL - COLLECTIONS
PRINCIPAL - COLLECTIONS
														Total
Scheduled Principal Received														251,232.75
Curtailments														55,292.16
Prepayments In Full														3,986,137.67
Repurchased/Substitutions														1,895,866.88
Liquidations														0.00
Insurance Principal														0.00
Other Additional Principal														0.00
Delinquent Principal														-191,156.51
Realized Losses														-0.00
Advanced Principal														191,156.51
TOTAL PRINCIPAL COLLECTED														6,188,529.46


PRINCIPAL - WITHDRAWALS

SPACE INTENTIONALLY LEFT BLANK



PRINCIPAL - OTHER ACCOUNTS
PRINCIPAL - OTHER ACCOUNTS
													Total
TOTAL PRINCIPAL OTHER ACCOUNTS													0.00





Page 4 of 22
IndyMac Residential Asset Securitization Trust 2004-A3

Mortgage Pass-Through Certificates
Mortgage Pass-Through Certificates
REMIC 2004-A3

September 27, 2004 Distribution

INTEREST - COLLECTIONS
INTEREST - COLLECTIONS
													Total
Scheduled Interest													1,211,593.05
Repurchased/Substitution Interest													10,936.35
Liquidation Interest													0.00
Insurance Interest													0.00
Other Additional Interest													0.00
Prepayment Interest Shortfalls													-2,902.27
Delinquent Interest													-922,767.19
Compensating Interest													2,902.27
Civil Relief Act Shortfalls													-0.00
Interest Advanced													874,429.38
TOTAL INTEREST COLLECTED													1,174,191.60


INTEREST - WITHDRAWALS
INTEREST - WITHDRAWALS
													Total
TOTAL INTEREST WITHDRAWALS													0.00



INTEREST - OTHER ACCOUNTS
INTEREST - OTHER ACCOUNTS
													Total
Prepayment Charges													4,766.72
TOTAL INTEREST OTHER ACCOUNTS													4,766.72



INTEREST - FEES
INTEREST - FEES
													Total
Current Servicing Fees													15,621.54
Trustee Fees													2,029.99
TOTAL INTEREST FEES													17,651.53




Page 5 of 22
IndyMac Residential Asset Securitization Trust 2004-A3

Mortgage Pass-Through Certificates
Mortgage Pass-Through Certificates
REMIC 2004-A3

September 27, 2004 Distribution
Credit Enhancement Report
ACCOUNTS

SPACE INTENTIONALLY LEFT BLANK



INSURANCE

SPACE INTENTIONALLY LEFT BLANK



STRUCTURAL FEATURES

SPACE INTENTIONALLY LEFT BLANK




Page 6 of 22
IndyMac Residential Asset Securitization Trust 2004-A3

Mortgage Pass-Through Certificates
Mortgage Pass-Through Certificates
REMIC 2004-A3

September 27, 2004 Distribution
Collateral Report


COLLATERAL



														Total



*Loan Count:*


Original													771
Prior													737
Prefunding													0
Scheduled Paid Offs													-0
Full Voluntary Prepayments													-15
Repurchases													-10
Liquidations													-0
Current													712
*Principal Balance:*


Original													255,123,765.35
Prior													243,599,438.68
Prefunding													0.00
Scheduled Principal													-251,232.75
Partial Prepayments													-55,292.16
Full Voluntary Prepayments													-3,986,137.67
Repurchases													-1,895,866.88
Liquidations													-0.00
Current													237,410,909.22





PREFUNDING

SPACE INTENTIONALLY LEFT BLANK






Page 7 of 22
IndyMac Residential Asset Securitization Trust 2004-A3

Mortgage Pass-Through Certificates
Mortgage Pass-Through Certificates
REMIC 2004-A3

September 27, 2004 Distribution

CHARACTERISTICS
CHARACTERISTICS
													Total
Weighted Average Coupon Original													6.04407%
Weighted Average Coupon Prior													6.02712%
Weighted Average Coupon Current													6.02233%
Weighted Average Months to Maturity Original													354
Weighted Average Months to Maturity Prior													351
Weighted Average Months to Maturity Current													350
Weighted Avg Remaining Amortization Term Original													354
Weighted Avg Remaining Amortization Term Prior													351
Weighted Avg Remaining Amortization Term Current													350
Weighted Average Seasoning Original													3.64
Weighted Average Seasoning Prior													6.40
Weighted Average Seasoning Current													7.30









Page 8 of 22
IndyMac Residential Asset Securitization Trust 2004-A3

Mortgage Pass-Through Certificates
Mortgage Pass-Through Certificates
REMIC 2004-A3

September 27, 2004 Distribution

ARM CHARACTERISTICS
ARM CHARACTERISTICS
													Total
Weighted Average Margin Original													0.00000%
Weighted Average Margin Prior													0.00000%
Weighted Average Margin Current													0.00000%
Weighted Average Max Rate Original													0.00000%
Weighted Average Max Rate Prior													0.00000%
Weighted Average Max Rate Current													0.00000%
Weighted Average Min Rate Original													0.00000%
Weighted Average Min Rate Prior													0.00000%
Weighted Average Min Rate Current													0.00000%
Weighted Average Cap Up Original													0.00000%
Weighted Average Cap Up Prior													0.00000%
Weighted Average Cap Up Current													0.00000%
Weighted Average Cap Down Original													0.00000%
Weighted Average Cap Down Prior													0.00000%
Weighted Average Cap Down Current													0.00000%




SERVICING FEES & ADVANCES

														Total




Current Servicing Fees													15,621.54
Delinquent Servicing Fees													48,337.81
TOTAL SERVICING FEES													63,959.36


Total Servicing Fees													63,959.36
Compensating Interest													-2,902.27
Delinquent Servicing Fees													-48,337.81
COLLECTED SERVICING FEES													12,719.28


Total Advaced Interest													874,429.38
Total Advaced Principal													191,156.51
Aggregate Advances with respect to this Distribution													1,065,585.89





ADDITIONAL COLLATERAL INFORMATION
													Total
Prepayment Interest Shortfall (PPIS)													2,902.27
Compensating Interest													-2,902.27
Net Prepayment Interest Shortfall (PPIS)													0.00
Weighted Average Net Mortgage Rate													5.697255%




Page 9 of 22
IndyMac Residential Asset Securitization Trust 2004-A3

Mortgage Pass-Through Certificates
Mortgage Pass-Through Certificates
REMIC 2004-A3

September 27, 2004 Distribution
Delinquency Report

	TOTAL
					< 1 PAYMENT	1 PAYMENT		2 PAYMENTS		3+ PAYMENTS		TOTAL
	DELINQUENT		Balance			3,602,182.36		154,867.12		143,934.47		3,900,983.95
			% Balance			1.52%		0.07%		0.06%		1.64%
			# Loans			10		1		2		13
			% # Loans			1.40%		0.14%		0.28%		1.83%
	FORECLOSURE		Balance		0.00	0.00		0.00		0.00		0.00
			% Balance		0.00%	0.00%		0.00%		0.00%		0.00%
			# Loans		0	0		0		0		0
			% # Loans		0.00%	0.00%		0.00%		0.00%		0.00%
	BANKRUPTCY		Balance		0.00	0.00		0.00		0.00		0.00
			% Balance		0.00%	0.00%		0.00%		0.00%		0.00%
			# Loans		0	0		0		0		0
			% # Loans		0.00%	0.00%		0.00%		0.00%		0.00%
	REO		Balance		0.00	0.00		0.00		0.00		0.00
			% Balance		0.00%	0.00%		0.00%		0.00%		0.00%
			# Loans		0	0		0		0		0
			% # Loans		0.00%	0.00%		0.00%		0.00%		0.00%
	TOTAL		Balance		0.00	3,602,182.36		154,867.12		143,934.47		3,900,983.95
			% Balance		0.00%	1.52%		0.07%		0.06%		1.64%
			# Loans		0	10		1		2		13
			% # Loans		0.00%	1.40%		0.14%		0.28%		1.83%









Page 10 of 22
IndyMac Residential Asset Securitization Trust 2004-A3

Mortgage Pass-Through Certificates
Mortgage Pass-Through Certificates
REMIC 2004-A3

September 27, 2004 Distribution
REO Report
Loan Number			Original		Stated			Current		State &

													First
&			Principal		Principal	Paid to		Note		LTV at		Original		Payment

Loan Group			Balance		Balance	Date		Rate		Origination		Term		Date
SPACE INTENTIONALLY LEFT BLANK
SPACE INTENTIONALLY LEFT BLANK



TOTAL



Page 11 of 22
IndyMac Residential Asset Securitization Trust 2004-A3

Mortgage Pass-Through Certificates
Mortgage Pass-Through Certificates
REMIC 2004-A3

September 27, 2004 Distribution
Foreclosure Report
Loan Number			Original		Stated			Current		State &

													First
&			Principal		Principal	Paid to		Note		LTV at		Original		Payment

Loan Group			Balance		Balance	Date		Rate		Origination		Term		Date




TOTAL



Page 12 of 22
IndyMac Residential Asset Securitization Trust 2004-A3

Mortgage Pass-Through Certificates
Mortgage Pass-Through Certificates
REMIC 2004-A3

September 27, 2004 Distribution
Prepayment Report

VOLUNTARY PREPAYMENTS
VOLUNTARY PREPAYMENTS

														Total




*Current*


Number of Paid in Full Loans													15
Number of Repurchased Loans													10
Total Number of Loans Prepaid in Full													25
Curtailments Amount													55,292.16
Paid in Full Balance													3,986,137.67
Repurchased Loans Balance													1,895,866.88
Total Prepayment Amount													5,937,296.71

*Cumulative*


Number of Paid in Full Loans													49
Number of Repurchased Loans													10
Total Number of Loans Prepaid in Full													59
Paid in Full Balance													14,123,689.16
Repurchased Loans Balance													1,895,866.88
Curtailments Amount													417,534.12
Total Prepayment Amount													16,437,090.16










Page 13 of 22
IndyMac Residential Asset Securitization Trust 2004-A3

Mortgage Pass-Through Certificates
Mortgage Pass-Through Certificates
REMIC 2004-A3

September 27, 2004 Distribution

VOLUNTARY PREPAYMENTS RATES
VOLUNTARY PREPAYMENTS RATES

														Total



SMM													2.44%
3 Months Avg SMM													1.24%
12 Months Avg SMM													1.33%
Avg SMM Since Cut-off													1.33%


CPR													25.65%
3 Months Avg CPR													13.87%
12 Months Avg CPR													14.82%
Avg CPR Since Cut-off													14.82%


PSA													1,755.90%
3 Months Avg PSA Approximation													1,088.86%
12 Months Avg PSA Approximation													1,360.75%
Avg PSA Since Cut-off Approximation													1,360.75%










Page 14 of 22
IndyMac Residential Asset Securitization Trust 2004-A3

Mortgage Pass-Through Certificates
Mortgage Pass-Through Certificates
REMIC 2004-A3

September 27, 2004 Distribution






PREPAYMENT CALCULATION METHODOLOGY

	Single Monthly Mortality (SMM): (Voluntary partial and full prepayments + Repurchases + Liquidations )/(Beg Principal Balance - Sched Principal)

	Conditional Prepayment Rate (CPR): 1-((1-SMM)^12)
	PSA Standard Prepayment Model: CPR/(0.002*min(30,WAS))
	PSA Standard Prepayment Model: CPR/(0.002*min(30,WAS))
	Average SMM over period between nth month and mth month (AvgSMMn,m): [(1-SMMn)(1-SMMn+1)...*(1-SMMm)]^(1/months in period n,m)
	Average CPR over period between the nth month and mth month (AvgCPRn,m): 1-((1-AvgSMMn,m)^12)

	Average PSA Approximation over period between the nth month and mth month: AvgCPRn,m/(0.002*Avg WASn,m))
	Average WASn,m: (min(30,WASn)+min(30,WASn+1)+...+min(30,WASm)/(number of months in the period n,m)

	Weighted Average Seasoning (WAS)

	Note: Prepayment rates are calculated since deal issue date and include partial and full voluntary prepayments, liquidations, and repurchases.
	Dates correspond to distribution dates.




Page 15 of 22
IndyMac Residential Asset Securitization Trust 2004-A3

Mortgage Pass-Through Certificates
Mortgage Pass-Through Certificates
REMIC 2004-A3

September 27, 2004 Distribution
Prepayment Detail Report
Prepayment Detail Report - Mortgage Loans Prepaid in Full During Current Distribution
Loan Number			Original						Current		State &		Type Prepayment		First
Loan Number			Original						Current		State &		Type Prepayment

&		Loan	Principal		Prepayment		Prepayment		Note		LTV at		&		Payment

Loan Group		Status	Balance		Amount		Date		Rate		Origination		Original Term		Date

239425 1			103,600.00		91,144.78		17-Aug-2004		6.875%		NY - 70.00%		Paid Off - 360		01-Jul-1997
239425 1			103,600.00		91,144.78		17-Aug-2004		6.875%		NY - 70.00%		Paid Off - 360		01-Jul-1997
257842 1			58,500.00		39,718.82		14-Sep-2004		7.875%		NY - 90.00%		Paid Off - 180		01-Oct-1997
3068072 1			507,000.00		495,765.30		20-Aug-2004		5.250%		CA - 65.76%		Paid Off - 360		01-Oct-2003
3153604 1			167,000.00		166,836.96		23-Aug-2004		6.875%		RI - 69.87%		Paid Off - 360		01-Mar-2003
3154359 1			151,000.00		149,631.63		31-Aug-2004		7.125%		ME - 83.43%		Paid Off - 360		01-Oct-2003
3160086 1			476,000.00		470,212.37		13-Sep-2004		6.125%		CA - 74.96%		Paid Off - 360		01-Mar-2004
3160637 1			520,000.00		515,742.44		19-Aug-2004		5.750%		VA - 66.67%		Paid Off - 360		01-Apr-2004
3236873 1			251,750.00		250,611.34		10-Sep-2004		7.500%		DC - 95.00%		Paid Off - 360		01-Mar-2004
3308432 1			578,000.00		573,536.90		01-Sep-2004		5.750%		CT - 85.00%		Paid Off - 360		01-Feb-2004
3434653 1			125,500.00		125,094.96		03-Sep-2004		7.125%		FL - 59.20%		Paid Off - 360		01-May-2004
3591176 1			155,100.00		154,384.12		27-Aug-2004		6.375%		TX - 94.98%		Paid Off - 360		01-May-2004
3596124 1			115,369.00		114,938.18		19-Aug-2004		6.375%		VA - 42.89%		Paid Off - 360		01-May-2004
3611770 1			206,157.00		205,303.89		01-Sep-2004		6.500%		CA - 62.28%		Paid Off - 360		01-May-2004
3652229 1			157,000.00		156,550.75		01-Sep-2004		6.250%		NY - 46.18%		Paid Off - 360		01-Jun-2004
3704775 1			477,000.00		476,665.23		27-Aug-2004		7.875%		MI - 90.00%		Paid Off - 360		01-May-2004
278128 1			166,800.00		155,136.21		31-Aug-2004		8.250%		ID - 80.00%		Repur/Subs - 360		01-Nov-1997
2904509 1			304,000.00		316,288.46		31-Aug-2004		6.750%		NY - 80.00%		Repur/Subs - 360		01-Sep-2003
3156978 1			110,000.00		109,263.79		31-Aug-2004		7.000%		NH - 40.74%		Repur/Subs - 360		01-Jan-2004
3156979 1			110,000.00		109,263.79		31-Aug-2004		7.000%		NH - 40.74%		Repur/Subs - 360		01-Jan-2004
3429026 1			110,000.00		109,627.17		31-Aug-2004		6.875%		FL - 64.33%		Repur/Subs - 360		01-May-2004
3454583 1			147,124.00		146,409.96		31-Aug-2004		7.000%		CA - 48.72%		Repur/Subs - 360		01-Apr-2004
3477565 1			350,000.00		348,543.43		31-Aug-2004		6.625%		AZ - 70.00%		Repur/Subs - 360		01-May-2004
3544418 1			210,000.00		209,270.63		31-Aug-2004		6.750%		CA - 51.85%		Repur/Subs - 360		01-May-2004
3589011 1			260,447.00		259,564.22		31-Aug-2004		6.875%		MA - 65.94%		Repur/Subs - 360		01-May-2004
3591909 1			132,961.00		132,499.22		31-Aug-2004		6.750%		AZ - 64.23%		Repur/Subs - 360		01-May-2004


TOTAL			5,950,308.00		5,882,004.55
TOTAL


Page 16 of 22
IndyMac Residential Asset Securitization Trust 2004-A3

Mortgage Pass-Through Certificates
Mortgage Pass-Through Certificates
REMIC 2004-A3

September 27, 2004 Distribution
Realized Loss Report

COLLATERAL REALIZED LOSSES



														Total


*Current*
*Current*



Number of Loans Liquidated													0
Collateral Principal Realized Loss/(Gain) Amount													0.00
Collateral Interest Realized Loss/(Gain) Amount													0.00
Net Liquidation Proceeds													0.00

*Cumulative*
*Cumulative*



Number of Loans Liquidated													0
Collateral Realized Loss/(Gain) Amount													0.00
Net Liquidation Proceeds													0.00





		Special Hazard Loss Coverage Amt													2,500,000.00
		Fraud Loss Coverage Amt													2,500,000.00
		Bankrupt Loss Coverage Amt													100,000.00
		Class B-1 Writedown Amount													0.00
		Class B-2 Writedown Amount													0.00
		Class B-3 Writedown Amount													0.00
		Class B-4 Writedown Amount													0.00
		Class B-5 Writedown Amount													0.00
		Class B-6 Writedown Amount													0.00









Page 17 of 22
IndyMac Residential Asset Securitization Trust 2004-A3

Mortgage Pass-Through Certificates
Mortgage Pass-Through Certificates
REMIC 2004-A3

September 27, 2004 Distribution


DEFAULT SPEEDS



														Total



MDR													0.00%
3 Months Avg MDR													0.00%
12 Months Avg MDR													0.00%
Avg MDR Since Cut-off													0.00%


CDR													0.00%
3 Months Avg CDR													0.00%
12 Months Avg CDR													0.00%
Avg CDR Since Cut-off													0.00%


SDA													0.00%
3 Months Avg SDA Approximation													0.00%
12 Months Avg SDA Approximation													0.00%
Avg SDA Since Cut-off Approximation													0.00%


Loss Severity Approximation for Current Period													0.00%
3 Months Avg Loss Severity Approximation													0.00%
12 Months Avg Loss Severity Approximation													0.00%
Avg Loss Severity Approximation Since Cut-off													0.00%












Page 18 of 22
IndyMac Residential Asset Securitization Trust 2004-A3

Mortgage Pass-Through Certificates
Mortgage Pass-Through Certificates
REMIC 2004-A3

September 27, 2004 Distribution





COLLATERAL REALIZED LOSS CALCULATION METHODOLOGY
	Monthly Default Rate (MDR): (Beg Principal Balance of Liquidated Loans)/(Total Beg Principal Balance)



	Conditional Default Rate (CDR): 1-((1-MDR)^12)

	SDA Standard Default Assumption: CDR/IF(WAS<61,MIN(30,WAS)0.02,MAX(0.03,MIN(30,WAS)0.02-0.0095*(WAS-60)))

	Average MDR over period between nth month and mth month (AvgMDRn,m): [(1-MDRn)(1-MDRn+1)...*(1-MDRm)]^(1/months in period n,m)
	Average CDR over period between the nth month and mth month (AvgCDRn,m): 1-((1-AvgMDRn,m)^12)

	Average SDA Approximation over period between the nth month and mth month:
	AvgCDRn,m/IF(Avg WASn,m<61,MIN(30,Avg WASn,m)0.02,MAX(0.03,MIN(30,Avg WASn,m)0.02-0.0095*(Avg WASn,m-60)))

	Average WASn,m: (WASn + WASn+1 +...+ WASm )/(number of months in the period n,m)
	Loss Severity Approximation for current period: sum(Realized Loss Amount)/sum(Beg Principal Balance of Liquidated Loans)

	Average Loss Severity Approximation over period between nth month and mth month: Avg(Loss Severityn,m)

	Note: Default rates are calculated since deal issue date and include realized gains and additional realized losses and gains from prior periods.
	Dates correspond to distribution dates.




Page 19 of 22
IndyMac Residential Asset Securitization Trust 2004-A3

Mortgage Pass-Through Certificates
Mortgage Pass-Through Certificates
REMIC 2004-A3

September 27, 2004 Distribution
Realized Loss Detail Report
Loan Number			Original		Prior			Current		State &

													First
&			Principal		Principal	Realized		Note		LTV at		Original		Payment

Loan Group			Balance		Balance	Loss/(Gain)		Rate		Origination		Term		Date

SPACE INTENTIONALLY LEFT BLANK
SPACE INTENTIONALLY LEFT BLANK



TOTAL



Page 20 of 22
IndyMac Residential Asset Securitization Trust 2004-A3

Mortgage Pass-Through Certificates
Mortgage Pass-Through Certificates
REMIC 2004-A3

September 27, 2004 Distribution
Triggers and Adj. Cert. Report
TRIGGER EVENTS
TRIGGER EVENTS
													Total
Has Optional Termination Date Reached (0=No,1=Yes)													0
Has Sr. Prepay Stepdown Condition Occurred (0=No,1=Yes)													0
Has Sr. Credit Supp. Depletion Date Occured (0=No,1=Yes)													0
Have all Prepayment Penalties Expired? (0=No,1=Yes)													0
Has Special Haz. Cov. Term Date Occured (0=No,1=Yes)													0
Has Fraud Loss Coverage Term Date Occured (0=No,1=Yes)													0
Has BK Loss Cov. Term Date Occured (0=No,1=Yes)													0



ADJUSTABLE RATE CERTIFICATE INFORMATION

SPACE INTENTIONALLY LEFT BLANK



ADDITIONAL INFORMATION
ADDITIONAL INFORMATION
													Total
Current Senior Percentage													95.298976%
Next Senior Percentage													95.219318%
Current Subordinate Percentage													4.701024%
Next Subordinate Percentage													4.780682%
Senior Prepayment Percentage													100.000000%
Next Senior Prepayment Percentage													100.000000%
Subordinate Prepayment Percentage													0.000000%
Next Subordinate Prepayment Percentage													0.000000%




Page 21 of 22
IndyMac Residential Asset Securitization Trust 2004-A3

Mortgage Pass-Through Certificates
Mortgage Pass-Through Certificates
REMIC 2004-A3

September 27, 2004 Distribution
Other Related Information
ADDITIONAL INFORMATION
ADDITIONAL INFORMATION
													Total
Current Scheduled Payments													1,462,825.80
Current Scheduled Payments 1 Month Prior													1,491,453.34
Current Scheduled Payments 2 Month Prior													1,497,469.04
Current Scheduled Payments 3 Month Prior													1,526,246.30
Current Scheduled Payments 4 Month Prior													1,544,635.43
Current Scheduled Payments 5 Month Prior													0.00
Current Scheduled Payments 6 Month Prior													0.00
Current Scheduled Payments 7 Month Prior													0.00
Current Scheduled Payments 8 Month Prior													0.00
Current Scheduled Payments 9 Month Prior													0.00
Current Scheduled Payments 10 Month Prior													0.00
Current Scheduled Payments 11 Month Prior													0.00

Delinquent 60+ Scheduled Payments													2,151.10
Delinq. 60+ Sched. Pmnts, 1 Month Prior													9,061.41
Delinq. 60+ Sched. Pmnts, 2 Month Prior													7,634.65
Delinq. 60+ Sched. Pmnts, 3 Month Prior													6,415.57
Delinq. 60+ Sched. Pmnts, 4 Month Prior													1,135.17
Delinq. 60+ Sched. Pmnts, 5 Month Prior													0.00
Delinq. 60+ Sched. Pmnts, 6 Month Prior													0.00
Delinq. 60+ Sched. Pmnts, 7 Month Prior													0.00
Delinq. 60+ Sched. Pmnts, 8 Month Prior													0.00
Delinq. 60+ Sched. Pmnts, 9 Month Prior													0.00
Delinq. 60+ Sched. Pmnts, 10 Month Prior													0.00
Delinq. 60+ Sched. Pmnts, 11 Month Prior													0.00




Page 22 of 22

Filing Compare · Residential Asset Securitization Trust 2004-A3