
                                       UNITED STATES
                           SECURITIES AND EXCHANGE COMMISSION
                                 Washington, D.C.  20549


                                        FORM 8-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):  December 27, 2004
                          (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 principal executive offices)     (Zip Code)


          Registrant's Telephone Number, Including Area Code:  (800) 669-2300


       (Former name or former address, if changed since last report.)

Check the appropriate box below if 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(c) under the
Exchange Act (17 CFR 240.13e-4(c))


     Item 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
     December 27, 2004.

                                    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:  Dec 28, 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 December 27, 2004.



IndyMac Residential Asset Securitization Trust 2004-A3

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

December 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:		December 27, 2004
									Factor Information:			(800) 735-7777
				Record Date:		November 30, 2004			Factor Information:			(800) 735-7777
									Main Phone Number:			(714) 247-6000
									Main Phone Number:			(714) 247-6000

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






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

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

December 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		96,000,993.32	360,003.72		1,500,250.18		1,860,253.90		0.00		0.00		94,500,743.14
A-1	PAC/SR	$	106,813,929.00		96,000,993.32	360,003.72		1,500,250.18		1,860,253.90		0.00		0.00		94,500,743.14
A-2	PAC/SR	$	29,131,071.00		26,182,088.61	55,200.57		409,159.13		464,359.70		0.00		0.00		25,772,929.48
A-3	INV/NTL	$	0.00		0.00	119,346.69		0.00		119,346.69		0.00		0.00		0.00
A-4	TAC/SR	$	73,048,000.00		57,779,868.09	252,786.92		1,749,006.94		2,001,793.86		0.00		0.00		56,030,861.15
A-5	SR	$	5,753,000.00		0.00	0.00		0.00		0.00		0.00		0.00		0.00
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		328,169.19	0.00		553.05		553.05		0.00		0.00		327,616.14
A-X	SR/NTL	$	0.00		0.00	75,424.80		0.00		75,424.80		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		5,715,170.95	25,003.87		19,170.10		44,173.97		0.00		0.00		5,696,000.85
B-2	SUB	$	1,786,000.00		1,667,313.84	7,294.50		5,592.58		12,887.08		0.00		0.00		1,661,721.26
B-3	SUB	$	1,276,000.00		1,191,205.18	5,211.52		3,995.60		9,207.12		0.00		0.00		1,187,209.58
B-4	SUB/NOF	$	893,000.00		833,656.91	3,647.25		2,796.29		6,443.54		0.00		0.00		830,860.62
B-5	SUB/NOF	$	383,000.00		357,548.26	1,564.27		1,199.31		2,763.58		0.00		0.00		356,348.95
B-6	SUB/NOF	$	1,020,571.00		952,750.41	4,168.28		3,195.76		7,364.04		0.00		0.00		949,554.65
P	NOF	$	100.00		100.00	0.00		0.00		0.00		0.00		0.00		100.00

Total			255,123,864.00		219,520,864.76	1,034,392.39		3,694,918.94		4,729,311.33		0.00		0.00		215,825,945.82
Total




Interest Accrual Detail Current Period Factor Information per $1,000 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	11/01/04		11/30/04		F-30/360	45660NE92		106,813,929.00		898.768487		3.370382		14.045455		17.415836	884.723032
A-2	11/25/04		12/24/04		A-30/360	45660NF26		29,131,071.00		898.768487		1.894904		14.045454		15.940358	884.723033
A-3	11/25/04		12/24/04		A-30/360	45660NF34		29,131,071.00		898.768487		4.096886		0.000000		4.096886	884.723033
A-4	11/01/04		11/30/04		F-30/360	45660NF42		73,048,000.00		790.984943		3.460559		23.943256		27.403815	767.041687
A-5	11/01/04		11/30/04		F-30/360	45660NF59		5,753,000.00		0.000000		0.000000		0.000000		0.000000	0.000000
A-6	11/01/04		11/30/04		F-30/360	45660NF67		3,000,000.00		1,000.000000		4.375000		0.000000		4.375000	1,000.000000
A-7	11/01/04		11/30/04		F-30/360	45660NF75		25,512,000.00		1,000.000000		4.375000		0.000000		4.375000	1,000.000000
PO	11/01/04		11/30/04		F-30/360	45660NF83		385,093.00		852.181655		0.000000		1.436147		1.436147	850.745508
A-X	11/01/04		11/30/04		F-30/360	45660NF91		235,616,408.78		854.171871		0.320117		0.000000		0.320117	838.598462
A-R	11/01/04		11/30/04		F-30/360	45660NG25		100.00		0.000000		0.000000		0.000000		0.000000	0.000000
B-1	11/01/04		11/30/04		F-30/360	45660NG33		6,122,000.00		933.546382		4.084265		3.131346		7.215611	930.415036
B-2	11/01/04		11/30/04		F-30/360	45660NG41		1,786,000.00		933.546383		4.084267		3.131344		7.215610	930.415039
B-3	11/01/04		11/30/04		F-30/360	45660NG58		1,276,000.00		933.546379		4.084263		3.131348		7.215611	930.415031
B-4	11/01/04		11/30/04		F-30/360			893,000.00		933.546372		4.084267		3.131344		7.215610	930.415028
B-5	11/01/04		11/30/04		F-30/360			383,000.00		933.546371		4.084256		3.131358		7.215614	930.415013
B-6	11/01/04		11/30/04		F-30/360			1,020,571.00		933.546426		4.084263		3.131345		7.215608	930.415081
P	11/01/04		11/30/04		30/360			100.00		1,000.000000		0.000000		0.000000		0.000000	1,000.000000



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

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

December 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		3,045,108.56		8,645,194.42	3,667,991.44		12,313,185.86		15,358,294.42		0.00		0.00		94,500,743.14
A-2	29,131,071.00		350,729.89		2,357,780.24	1,000,361.28		3,358,141.52		3,708,871.41		0.00		0.00		25,772,929.48
A-3	0.00		1,125,686.39		0.00	0.00		0.00		1,125,686.39		0.00		0.00		0.00
A-4	73,048,000.00		2,418,839.66		7,475,208.04	9,541,930.81		17,017,138.85		19,435,978.51		0.00		0.00		56,030,861.15
A-5	5,753,000.00		92,597.95		4,076,855.43	1,676,144.57		5,753,000.00		5,845,597.95		0.00		0.00		0.00
A-6	3,000,000.00		105,000.00		0.00	0.00		0.00		105,000.00		0.00		0.00		3,000,000.00
A-7	25,512,000.00		892,920.00		0.00	0.00		0.00		892,920.00		0.00		0.00		25,512,000.00
PO	385,093.00		0.00		55,238.91	2,237.95		57,476.86		57,476.86		0.00		0.00		327,616.14
A-X	0.00		725,889.96		0.00	0.00		0.00		725,889.96		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		210,760.66		0.01	425,999.14		425,999.15		636,759.81		0.00		0.00		5,696,000.85
B-2	1,786,000.00		61,486.20		0.00	124,278.74		124,278.74		185,764.94		0.00		0.00		1,661,721.26
B-3	1,276,000.00		43,928.55		0.00	88,790.42		88,790.42		132,718.97		0.00		0.00		1,187,209.58
B-4	893,000.00		30,743.12		0.00	62,139.38		62,139.38		92,882.50		0.00		0.00		830,860.62
B-5	383,000.00		13,185.45		0.00	26,651.05		26,651.05		39,836.50		0.00		0.00		356,348.95
B-6	1,020,571.00		35,134.96		0.00	71,016.35		71,016.35		106,151.31		0.00		0.00		949,554.65
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		9,161,682.88		22,610,277.05	16,687,641.13		39,297,918.18		48,459,601.06		0.00		0.00		215,825,945.82


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%		96,000,993.32		360,003.72	0.00		0.00		0.00		360,003.72		360,003.72		0.00
A-2	2.53000%		26,182,088.61		55,200.57	0.00		0.00		0.00		55,200.57		55,200.57		0.00
A-3	5.47000%		26,182,088.61		119,346.69	0.00		0.00		0.00		119,346.69		119,346.69		0.00
A-4	5.25000%		57,779,868.09		252,786.92	0.00		0.00		0.00		252,786.92		252,786.92		0.00
A-5	0.00000%		0.00		0.00	0.00		0.00		0.00		0.00		0.00		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%		328,169.19		0.00	0.00		0.00		0.00		0.00		0.00		0.00
A-X	0.44972%		201,256,908.80		75,424.78	0.00		0.00		0.00		75,424.78		75,424.80		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%		5,715,170.95		25,003.87	0.00		0.00		0.00		25,003.87		25,003.87		0.00
B-2	5.25000%		1,667,313.84		7,294.50	0.00		0.00		0.00		7,294.50		7,294.50		0.00
B-3	5.25000%		1,191,205.18		5,211.52	0.00		0.00		0.00		5,211.52		5,211.52		0.00
B-4	5.25000%		833,656.91		3,647.25	0.00		0.00		0.00		3,647.25		3,647.25		0.00
B-5	5.25000%		357,548.26		1,564.27	0.00		0.00		0.00		1,564.27		1,564.27		0.00
B-6	5.25000%		952,750.41		4,168.28	0.00		0.00		0.00		4,168.28		4,168.28		0.00
P	0.00000%		100.00		0.00	0.00		0.00		0.00		0.00		0.00		0.00

Total			446,959,862.17		1,034,392.37	0.00		0.00		0.00		1,034,392.37		1,034,392.39		0.00



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

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

December 27, 2004 Distribution
Collection Account Report
SUMMARY
SUMMARY
													Total
Principal Collections													3,694,918.94
Principal Withrawals													0.00
Principal Other Accounts													0.00
TOTAL NET PRINCIPAL													3,694,918.94
Interest Collections													1,045,715.89
Interest Withdrawals													-0.00
Interest Other Accounts													0.00
Interest Fees													-11,323.50
TOTAL NET INTEREST													1,034,392.39
TOTAL AVAILABLE FUNDS FOR DISTRIBUTION													4,729,311.33



PRINCIPAL - COLLECTIONS
PRINCIPAL - COLLECTIONS
														Total
Scheduled Principal Received														233,904.24
Curtailments														28,669.18
Prepayments In Full														2,930,516.49
Repurchased/Substitutions														501,829.03
Liquidations														0.00
Insurance Principal														0.00
Other Additional Principal														0.00
Delinquent Principal														-195,675.81
Realized Losses														-0.00
Advanced Principal														195,675.81
TOTAL PRINCIPAL COLLECTED														3,694,918.94


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
2004-A3

December 27, 2004 Distribution

INTEREST - COLLECTIONS
INTEREST - COLLECTIONS
													Total
Scheduled Interest													1,091,056.10
Repurchased/Substitution Interest													2,770.51
Liquidation Interest													0.00
Insurance Interest													0.00
Other Additional Interest													0.00
Prepayment Interest Shortfalls													-2,381.17
Delinquent Interest													-912,700.63
Compensating Interest													2,381.17
Civil Relief Act Shortfalls													-0.00
Interest Advanced													864,589.91
TOTAL INTEREST COLLECTED													1,045,715.89


INTEREST - WITHDRAWALS
INTEREST - WITHDRAWALS
													Total
TOTAL INTEREST WITHDRAWALS													0.00



INTEREST - OTHER ACCOUNTS
INTEREST - OTHER ACCOUNTS
													Total
Prepayment Charges													0.00
TOTAL INTEREST OTHER ACCOUNTS													0.00



INTEREST - FEES
INTEREST - FEES
													Total
Current Servicing Fees													9,494.16
Trustee Fees													1,829.34
TOTAL INTEREST FEES													11,323.50




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

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

December 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
2004-A3

December 27, 2004 Distribution
Collateral Report


COLLATERAL



														Total



*Loan Count:*


Original													771
Prior													633
Prefunding													0
Scheduled Paid Offs													-0
Full Voluntary Prepayments													-11
Repurchases													-1
Liquidations													-0
Current													621
*Principal Balance:*


Original													255,123,765.35
Prior													219,520,766.07
Prefunding													0.00
Scheduled Principal													-233,904.24
Partial Prepayments													-28,669.18
Full Voluntary Prepayments													-2,930,516.49
Repurchases													-501,829.03
Liquidations													-0.00
Current													215,825,847.13





PREFUNDING

SPACE INTENTIONALLY LEFT BLANK






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

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

December 27, 2004 Distribution

CHARACTERISTICS
CHARACTERISTICS
													Total
Weighted Average Coupon Original													6.04407%
Weighted Average Coupon Prior													5.98978%
Weighted Average Coupon Current													5.97935%
Weighted Average Months to Maturity Original													354
Weighted Average Months to Maturity Prior													348
Weighted Average Months to Maturity Current													347
Weighted Avg Remaining Amortization Term Original													354
Weighted Avg Remaining Amortization Term Prior													348
Weighted Avg Remaining Amortization Term Current													347
Weighted Average Seasoning Original													3.64
Weighted Average Seasoning Prior													9.41
Weighted Average Seasoning Current													10.40









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

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

December 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													9,494.16
Delinquent Servicing Fees													48,110.72
TOTAL SERVICING FEES													57,604.88


Total Servicing Fees													57,604.88
Compensating Interest													-2,381.17
Delinquent Servicing Fees													-48,110.72
COLLECTED SERVICING FEES													7,113.00


Total Advaced Interest													864,589.91
Total Advaced Principal													195,675.81
Aggregate Advances with respect to this Distribution													1,060,265.72





ADDITIONAL COLLATERAL INFORMATION
													Total
Prepayment Interest Shortfall (PPIS)													2,381.17
Compensating Interest													-2,381.17
Net Prepayment Interest Shortfall (PPIS)													0.00
Weighted Average Net Mortgage Rate													5.654458%




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

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

December 27, 2004 Distribution
Delinquency Report

	TOTAL
					< 1 PAYMENT	1 PAYMENT		2 PAYMENTS		3+ PAYMENTS		TOTAL
	DELINQUENT		Balance			2,574,961.39		1,594,687.18		705,615.32		4,875,263.89
			% Balance			1.19%		0.74%		0.33%		2.26%
			# Loans			9		4		2		15
			% # Loans			1.45%		0.64%		0.32%		2.42%
	FORECLOSURE		Balance		0.00	0.00		0.00		248,211.23		248,211.23
			% Balance		0.00%	0.00%		0.00%		0.12%		0.12%
			# Loans		0	0		0		2		2
			% # Loans		0.00%	0.00%		0.00%		0.32%		0.32%
	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	2,574,961.39		1,594,687.18		953,826.55		5,123,475.12
			% Balance		0.00%	1.19%		0.74%		0.44%		2.37%
			# Loans		0	9		4		4		17
			% # Loans		0.00%	1.45%		0.64%		0.64%		2.74%









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

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

December 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
2004-A3

December 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
323522 1
323522 1			100,800.00		93,703.01	01-Apr-2004		7.000%		OR - 80.00%		360		01-Jun-1998

2155643 1			156,560.00		154,508.22	01-Jun-2004		7.875%		CT - 95.00%		360		01-Jul-2003


TOTAL			257,360.00		248,211.23



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

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

December 27, 2004 Distribution
Prepayment Report

VOLUNTARY PREPAYMENTS
VOLUNTARY PREPAYMENTS

														Total




*Current*


Number of Paid in Full Loans													11
Number of Repurchased Loans													1
Total Number of Loans Prepaid in Full													12
Curtailments Amount													28,669.18
Paid in Full Balance													2,930,516.49
Repurchased Loans Balance													501,829.03
Total Prepayment Amount													3,461,014.70

*Cumulative*


Number of Paid in Full Loans													76
Number of Repurchased Loans													74
Total Number of Loans Prepaid in Full													150
Paid in Full Balance													22,119,507.65
Repurchased Loans Balance													14,701,745.94
Curtailments Amount													488,810.80
Total Prepayment Amount													37,310,064.39










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

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

December 27, 2004 Distribution

VOLUNTARY PREPAYMENTS RATES
VOLUNTARY PREPAYMENTS RATES

														Total



SMM													1.58%
3 Months Avg SMM													3.03%
12 Months Avg SMM													1.97%
Avg SMM Since Cut-off													1.97%


CPR													17.38%
3 Months Avg CPR													30.84%
12 Months Avg CPR													21.22%
Avg CPR Since Cut-off													21.22%


PSA													835.48%
3 Months Avg PSA Approximation													1,642.59%
12 Months Avg PSA Approximation													1,532.54%
Avg PSA Since Cut-off Approximation													1,532.54%










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

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

December 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
2004-A3

December 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

606131 1			175,500.00		161,824.15		02-Dec-2004		7.625%		CA - 90.00%		Paid Off - 360		8/1/2000
606131 1			175,500.00		161,824.15		02-Dec-2004		7.625%		CA - 90.00%		Paid Off - 360		8/1/2000
3157680 1			135,000.00		133,713.65		01-Dec-2004		7.125%		FL - 45.00%		Paid Off - 360		1/1/2004
3160084 1			390,000.00		386,757.25		29-Nov-2004		6.500%		MA - 77.38%		Paid Off - 360		3/1/2004
3160634 1			442,100.00		438,431.67		29-Nov-2004		5.875%		PA - 75.57%		Paid Off - 360		4/1/2004
3292589 1			80,000.00		79,600.77		22-Nov-2004		7.000%		NH - 19.09%		Paid Off - 360		6/1/2004
3421535 1			210,000.00		208,549.20		24-Nov-2004		6.125%		CA - 64.62%		Paid Off - 360		5/1/2004
3546801 1			136,200.00		135,211.59		02-Dec-2004		5.875%		MD - 66.44%		Paid Off - 360		5/1/2004
3610349 1			452,000.00		449,573.97		19-Nov-2004		6.625%		DC - 80.00%		Paid Off - 360		6/1/2004
3628424 1			476,000.00		472,320.29		06-Dec-2004		6.250%		CA - 80.00%		Paid Off - 360		4/1/2004
3628837 1			390,000.00		389,976.96		18-Nov-2004		6.000%		CA - 60.00%		Paid Off - 360		4/1/2004
3660148 1			75,000.00		74,556.99		01-Dec-2004		6.125%		FL - 39.27%		Paid Off - 360		6/1/2004
3485961 1			505,000.00		501,829.03		30-Nov-2004		6.625%		NY - 51.79%		Repur/Subs - 360		5/1/2004


TOTAL			3,466,800.00		3,432,345.52
TOTAL


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

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

December 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
2004-A3

December 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
2004-A3

December 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
2004-A3

December 27, 2004 Distribution
Realized Loss Detail Report
Loan Number			Current		State &			Prior		Realized				Cumulative
														Cumulative
&		Loan	Note		LTV at	Original		Principal		Loss/(Gain)		Realized		Realized

Loan Group		Status	Rate		Origination	Term		Balance		Revision		Loss/(Gain)		Loss/(Gain)
Loan Group		Status	Rate		Origination	Term		Balance		Revision		Loss/(Gain)		Loss/(Gain)




TOTAL



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

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

December 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													95.110397%
Next Senior Percentage													95.043256%
Current Subordinate Percentage													4.889603%
Next Subordinate Percentage													4.956744%
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
2004-A3

December 27, 2004 Distribution
Other Related Information
ADDITIONAL INFORMATION
ADDITIONAL INFORMATION
													Total
Current Scheduled Payments													1,324,960.34
Current Scheduled Payments 1 Month Prior													1,339,840.90
Current Scheduled Payments 2 Month Prior													1,394,927.46
Current Scheduled Payments 3 Month Prior													1,462,825.80
Current Scheduled Payments 4 Month Prior													1,491,453.34
Current Scheduled Payments 5 Month Prior													1,497,469.04
Current Scheduled Payments 6 Month Prior													1,526,246.30
Current Scheduled Payments 7 Month Prior													1,544,635.43
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													16,088.12
Delinq. 60+ Sched. Pmnts, 1 Month Prior													16,392.75
Delinq. 60+ Sched. Pmnts, 2 Month Prior													10,412.12
Delinq. 60+ Sched. Pmnts, 3 Month Prior													2,151.10
Delinq. 60+ Sched. Pmnts, 4 Month Prior													9,061.41
Delinq. 60+ Sched. Pmnts, 5 Month Prior													7,634.65
Delinq. 60+ Sched. Pmnts, 6 Month Prior													6,415.57
Delinq. 60+ Sched. Pmnts, 7 Month Prior													1,135.17
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

Residential Asset Securitization Trust 2004-A3 8-K