

                           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):  September 25, 2003


                                  INDYMAC MBS, INC.
           as Depositor, IndyMac Bank, F.S.B. as Seller and as Master Servicer,
              and Deutsche Bank National Trust Company, as trustee
              under the Pooling and Servicing Agreement, dated as of
           March 1, 2003, providing for the issuance of IndyMac MBS, Inc.
           Residential Asset-Securitization Trust Series 2003-A4 Mortgage
           Pass-Through Certificates Series 2003-D.


              INDYMAC MBS INC RESIDENTIAL ASSET SECUR TRUST 2003-A4
                 (Exact name of Registrant as specified in its Charter)


                                        DELAWARE
                     (State or Other Jurisdiction of Incorporation)

               333-102888-03                         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


     Item 5.  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 7.  Financial Statement and Exhibits

     Exhibits:  (as noted in Item 5 above)

     Monthly Remittance Statement to the Certificateholders dated as of
     September 25, 2003.



                                     SIGNATURE


               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,
                                  not in it individual capacity, but solely
                                  as a duly authorized agent of the Registrant
                                  pursuant to the Pooling and Servicing
                                  Agreement, dated as of March 1, 2003.


          Date:  Oct 01, 2003               By:  /s/  Katherine M. Wannenmacher
                                            Katherine M. Wannenmacher
                                            Vice President



                                   EXHIBIT INDEX

          DOCUMENT

          Monthly Remittance Statement to the Certificateholders
          dated as of September 25, 2003.


	IndyMac Residential Asset Securitization Trust 2003-A4
	Mortgage Pass-Through Certificates


	September 25, 2003 Distribution


	Contents



			TABLE OF CONTENTS

								Page

			1.	Contents				1
			2.	Certificate Payment Report				2
			3.	Collection Account Report				4
			4.	Credit Enhancement Report				7
			5.	Collateral Report				8
			6.	Delinquency Report				11
			7.	REO Report				12
			8.	Prepayment Report				13
			9.	Prepayment Detail Report				16
			10.	Realized Loss Report				17
			11.	Realized Loss Detail Report				20
			12.	Triggers, Adj. Rate Cert. and Miscellaneous Report				21





				Total Number of Pages				21



			CONTACTS

				Administrator: James Noriega
				Direct Phone Number: (714)247-6281
				Address: Deutsche Bank
				1761 E. St. Andrew Place, Santa Ana, CA 92705

				Web Site: https://www.corporatetrust.db.com/invr
				Factor Information: (800) 735-7777
				Main Phone Number: (714) 247-6000



ISSUANCE INFORMATION

	Seller:		IndyMac Bank					Cut-Off Date: March 1, 2003
	Certificate Insurer(s):							Closing Date: March 27, 2003
								First Payment Date: April 25, 2003
	Servicer(s):		IndyMac Bank


								Distribution Date: September 25, 2003
	Underwriter(s):		Bear, Stearns & Co. Inc					Record Date: August 29, 2003







						Page 1 of 21					© COPYRIGHT 2003 Deutsche Bank
	IndyMac Residential Asset Securitization Trust 2003-A4
	Mortgage Pass-Through Certificates
	Series 2003-A4
	Certificate Payment Report for September 25, 2003 Distribution


	Distribution in Dollars - Current Period
					Prior						Current
	Class	Original			Principal			Total	Realized	Deferred	Principal
Class	Type	Face Value			Balance	Interest	Principal	Distribution	Losses	Interest	Balance
					(1)	(2)	(3)	(4)=(2)+(3)	(5)	(6)	(7)=(1)-(3)-(5)+(6)

A-1	PAC,AS	121,359,118.00			113,000,069.21	400,208.58	1,704,548.23	2,104,756.81	-	-	111,295,520.99
A-2	PAC,CPT,AS	55,000,000.00			49,910,505.31	239,154.50	2,736,117.09	2,975,271.59	-	-	47,174,388.22
A-3	FLT,PAC,AS	66,195,882.00			61,636,400.88	77,559.14	929,753.57	1,007,312.71	-	-	60,706,647.31
A-4	IO,INV,NTL	-			-	359,032.04	-	359,032.04	-	-	-
A-5	TAC,AS	45,298,500.00			42,800,553.94	214,002.77	1,067,927.98	1,281,930.75	-	-	41,732,625.96
A-6	PO,TAC	1,969,500.00			1,860,893.65	-	46,431.65	46,431.65	-	-	1,814,462.00
A-7	FLT,DLY,SUP	23,513,906.00			16,129,421.12	31,317.96	538,914.26	570,232.22	-	-	15,590,506.87
A-8	INV,DLY,SUP	9,201,094.00			6,311,512.85	76,211.52	210,879.50	287,091.02	-	-	6,100,633.35
A-9	SEQ,AS	11,500,000.00			11,500,000.00	55,104.17	-	55,104.17	-	-	11,500,000.00
PO	PO,RSTP	210,914.00			192,014.58	-	2,535.00	2,535.00	-	-	189,479.58
A-X	IO,CSTR,NTL	-			-	97,538.21	-	97,538.21	-	-	-
A-R	R,AS	100.00			-	-	-	-	-	-	-
B-1	SUB,NAS	8,400,000.00			8,339,533.86	39,960.27	19,592.74	59,553.01	-	-	8,319,941.13
B-2	SUB,NAS	2,625,000.00			2,606,104.33	12,487.58	6,122.73	18,610.31	-	-	2,599,981.60
B-3	SUB,NAS	1,925,000.00			1,911,143.18	9,157.56	4,490.00	13,647.56	-	-	1,906,653.17
B-4	SUB,NAS	1,050,000.00			1,042,441.73	4,995.03	2,449.09	7,444.12	-	-	1,039,992.64
B-5	SUB,NAS	525,000.00			521,220.87	2,497.52	1,224.55	3,722.07	-	-	519,996.32
B-6	SUB,NAS	1,225,985.52			1,217,160.47	5,832.23	2,859.55	8,691.78	-	-	1,214,300.91
P		100.00			100.00	-	-	-	-	-	100.00



Total		350,000,099.52			318,979,075.99	1,625,059.08	7,273,845.93	8,898,905.01	-	-	311,705,230.06


	Interest Accrual Detail				Current Period Factor Information per $1,000 of Original Face
						Orig. Principal	Prior				Current
	Period	Period				(with Notional)	Principal			Total	Principal
Class	Starting	Ending		Method	Cusip	Balance	Balance	Interest	Principal	Distribution	Balance
							(1)	(2)	(3)	(4)=(2)+(3)	(5)

A-1				F-30/360	45660NPF6	121,359,118.00	931.121378	3.297722	14.045490	17.343211	917.075889
A-2				F-30/360	45660NPG4	55,000,000.00	907.463733	4.348264	49.747583	54.095847	857.716150
A-3				A-30/360	45660NPH2	66,195,882.00	931.121378	1.171661	14.045490	15.217151	917.075889
A-4				A-30/360	45660NPJ8	66,195,882.00	931.121378	5.423782	-	5.423782	917.075889
A-5				F-30/360	45660NPK5	45,298,500.00	944.855877	4.724279	23.575350	28.299629	921.280527
A-6				-30/360	45660NPL3	1,969,500.00	944.855877	-	23.575350	23.575350	921.280527
A-7				A-30/360	45660NPM1	23,513,906.00	685.952437	1.331891	22.918959	24.250850	663.033478
A-8				A-30/360	45660NPN9	9,201,094.00	685.952437	8.282876	22.918959	31.201835	663.033478
A-9				F-30/360	45660NPP4	11,500,000.00	1,000.000000	4.791667	-	4.791667	1,000.000000
PO				-30/360	45660NPQ2	210,914.00	910.392767	-	12.019117	12.019117	898.373650
A-X				A-30/360	45660NPR0	275,071,562.00	905.812354	0.354592	-	0.354592	885.943404
A-R				F-30/360	45660NPS8	100.00	-	-	-	-	-
B-1				F-30/360	45660NPT6	8,400,000.00	992.801650	4.757175	2.332469	7.089644	990.469182
B-2				F-30/360	45660NPU3	2,625,000.00	992.801650	4.757173	2.332469	7.089642	990.469182
B-3				F-30/360	45660NPV1	1,925,000.00	992.801650	4.757174	2.332469	7.089643	990.469182
B-4				F-30/360	45660NPW9	1,050,000.00	992.801650	4.757171	2.332469	7.089640	990.469182
B-5				F-30/360	45660NPX7	525,000.00	992.801650	4.757181	2.332469	7.089650	990.469182
B-6				F-30/360	45660NPY5	1,225,985.52	992.801667	4.757177	2.332452	7.089629	990.469214
P				-		100.00	1,000.000000	-	-	-	1,000.000000


							Page 2 of 21				© COPYRIGHT 2003 Deutsche Bank
	IndyMac Residential Asset Securitization Trust 2003-A4
	Mortgage Pass-Through Certificates
	Series 2003-A4
	Certificate Payment Report for September 25, 2003 Distribution


	Distribution in Dollars - to Date
											Current
	Original				Unscheduled	Scheduled	Total	Total	Realized	Deferred	Principal
Class	Face Value		Interest		Principal	Principal	Principal	Distribution	Losses	Interest	Balance
	(1)		(2)		(3)	(4)	(5)=(3)+(4)	(6)=(2)+(5)	(7)	(8)	(9)=(1)-(5)-(7)+(8)

A-1	121,359,118.00		2,498,125.05		-	10,063,597.01	10,063,597.01	12,561,722.06	-	-	111,295,520.99
A-2	55,000,000.00		1,531,542.88		-	7,825,611.78	7,825,611.78	9,357,154.66	-	-	47,174,388.22
A-3	66,195,882.00		515,064.35		-	5,489,234.69	5,489,234.69	6,004,299.04	-	-	60,706,647.31
A-4	-		2,210,162.94		-	-	-	2,210,162.94	-	-	-
A-5	45,298,500.00		1,336,538.57		-	3,565,874.04	3,565,874.04	4,902,412.61	-	-	41,732,625.96
A-6	1,969,500.00		-		-	155,038.00	155,038.00	155,038.00	-	-	1,814,462.00
A-7	23,513,906.00		263,776.24		-	7,923,399.13	7,923,399.13	8,187,175.37	-	-	15,590,506.87
A-8	9,201,094.00		603,947.72		-	3,100,460.65	3,100,460.65	3,704,408.37	-	-	6,100,633.35
A-9	11,500,000.00		330,625.02		-	-	-	330,625.02	-	-	11,500,000.00
PO	210,914.00		-		-	21,434.42	21,434.42	21,434.42	-	-	189,479.58
A-X	-		629,613.97		-	-	-	629,613.97	-	-	-
A-R	100.00		47.49		-	100.00	100.00	147.49	-	-	-
B-1	8,400,000.00		240,717.00		-	80,058.87	80,058.87	320,775.87	-	-	8,319,941.13
B-2	2,625,000.00		75,224.07		-	25,018.40	25,018.40	100,242.47	-	-	2,599,981.60
B-3	1,925,000.00		55,164.31		-	18,346.83	18,346.83	73,511.14	-	-	1,906,653.17
B-4	1,050,000.00		30,089.62		-	10,007.36	10,007.36	40,096.98	-	-	1,039,992.64
B-5	525,000.00		15,044.82		-	5,003.68	5,003.68	20,048.50	-	-	519,996.32
B-6	1,225,985.52		35,132.81		-	11,684.61	11,684.61	46,817.42	-	-	1,214,300.91
P	100.00		17,786.27		-	-	-	17,786.27	-	-	100.00



Total	350,000,099.52		10,388,603.13		-	38,294,869.46	38,294,869.46	48,683,472.59	-	-	311,705,230.06


	Interest Detail
	Pass-	Prior Principal				Non-	Prior	Unscheduled		Paid or	Current
	Through	(with Notional)			Accrued	Supported	Unpaid	Interest	Optimal	Deferred	Unpaid
Class	Rate	Balance			Interest	Interest SF	Interest	Adjustments	Interest	Interest	Interest
					(1)	(2)	(3)	(4)	(5)=(1)-(2)+(3)+(4)	(6)	(7)=(5)-(6)

A-1	4.25000%	113,000,069.21			400,208.58	-	-	-	400,208.58	400,208.58	-
A-2	5.75000%	49,910,505.31			239,154.50	-	-	-	239,154.50	239,154.50	-
A-3	1.51000%	61,636,400.88			77,559.14	-	-	-	77,559.14	77,559.14	-
A-4	6.99000%	61,636,400.88			359,032.04	-	-	-	359,032.04	359,032.04	-
A-5	6.00000%	42,800,553.94			214,002.77	-	-	-	214,002.77	214,002.77	-
A-6		1,860,893.65			-	-	-	-	-	-	-
A-7	2.33000%	16,129,421.12			31,317.96	-	-	-	31,317.96	31,317.96	-
A-8	########	6,311,512.85			76,211.52	-	-	-	76,211.52	76,211.52	-
A-9	5.75000%	11,500,000.00			55,104.17	-	-	-	55,104.17	55,104.17	-
PO		192,014.58			-	-	-	-	-	-	-
A-X	0.46976%	249,163,219.22			97,538.21	-	-	-	97,538.21	97,538.21	-
A-R	5.75000%	-			-	-	-	-	-	-	-
B-1	5.75000%	8,339,533.86			39,960.27	-	-	-	39,960.27	39,960.27	-
B-2	5.75000%	2,606,104.33			12,487.58	-	-	-	12,487.58	12,487.58	-
B-3	5.75000%	1,911,143.18			9,157.56	-	-	-	9,157.56	9,157.56	-
B-4	5.75000%	1,042,441.73			4,995.03	-	-	-	4,995.03	4,995.03	-
B-5	5.75000%	521,220.87			2,497.52	-	-	-	2,497.52	2,497.52	-
B-6	5.75000%	1,217,160.47			5,832.23	-	-	-	5,832.23	5,832.23	-
P		100.00			-	-	-	-	-	-	-



Total		629,778,696.09			1,625,059.08	-	-	-	1,625,059.08	1,625,059.08	-


							Page 3 of 21				© COPYRIGHT 2003 Deutsche Bank
	IndyMac Residential Asset Securitization Trust 2003-A4
	Mortgage Pass-Through Certificates

	Collection Account Report for September 25, 2003 Distribution


	Collection Account Report


SUMMARY								TOTAL

	Principal Collections							7,273,845.95
	Principal Withdrawals							0.00
	Principal Other Accounts							0.00
	TOTAL PRINCIPAL							7,273,845.95

	Interest Collections							1,708,041.15
	Interest Withdrawals							(82,982.09)
	Interest Other Accounts							0.00
	TOTAL INTEREST							1,625,059.06

	TOTAL AVAILABLE FUNDS TO BONDHOLDERS							8,898,905.01

	Interest Payable to Bondholders							1,625,059.06

	Principal Payment Amount Payable to Bondholders							7,273,845.95


PRINCIPAL - COLLECTIONS								TOTAL

	Scheduled Principal							302,467.79
	Curtailments							155,974.54
	Prepayments in Full							6,368,265.86
	Repurchases/Substitutions							447,137.76
	Liquidations							0.00
	Insurance Principal							0.00
	Other Additional Principal							0.00
	LESS: Delinquent Principal							(4,838.49)
	LESS: Realized Losses							0.00
	Principal Advanced							4,838.49
	TOTAL PRINCIPAL							7,273,845.95


				Page 4 of 21				© COPYRIGHT 2003 Deutsche Bank
	IndyMac Residential Asset Securitization Trust 2003-A4
	Mortgage Pass-Through Certificates

	Collection Account Report for September 25, 2003 Distribution


	Collection Account Report


PRINCIPAL - WITHDRAWALS								TOTAL
SPACE INTENTIONALLY LEFT BLANK


PRINCIPAL - OTHER ACCOUNTS								TOTAL
SPACE INTENTIONALLY LEFT BLANK


INTEREST - COLLECTIONS								TOTAL

	Scheduled Interest							1,705,060.24
	Repurchases/Substitutions							2,980.92
	Liquidations							0.00
	Insurance Interest							0.00
	Other Additional Interest							0.00
	Prepayment Interest Shortfalls							(9,988.49)
	Delinquent Interest							(29,721.36)
	Interest Realized Losses							0.00
	Compensating Interest							9,988.49
	Interest Advanced							29,721.35
	Capitalized Interest							0.00
	TOTAL INTEREST							1,708,041.15


				Page 5 of 21				© COPYRIGHT 2003 Deutsche Bank
	IndyMac Residential Asset Securitization Trust 2003-A4
	Mortgage Pass-Through Certificates

	Collection Account Report for September 25, 2003 Distribution


	Collection Account Report


INTEREST - WITHDRAWALS								TOTAL
SPACE INTENTIONALLY LEFT BLANK


INTEREST - OTHER ACCOUNTS								TOTAL
SPACE INTENTIONALLY LEFT BLANK


INTEREST - FEES								TOTAL

	Master Servicing Fees							0.00
	Current Servicing Fees							79,661.23
	Delinquent Servicing Fees							1,327.24
	Trustee Fees							1,993.62
	TOTAL INTEREST FEES							82,982.09


				Page 6 of 21				© COPYRIGHT 2003 Deutsche Bank
	IndyMac Residential Asset Securitization Trust 2003-A4
	Mortgage Pass-Through Certificates

	Credit Enhancement Report for September 25, 2003 Distribution


	Credit Enhancement Report


ACCOUNTS								TOTAL
SPACE INTENTIONALLY LEFT BLANK


INSURANCE								TOTAL
SPACE INTENTIONALLY LEFT BLANK


STRUCTURAL FEATURES								TOTAL
SPACE INTENTIONALLY LEFT BLANK


				Page 7 of 21				© COPYRIGHT 2003 Deutsche Bank
	IndyMac Residential Asset Securitization Trust 2003-A4
	Mortgage Pass-Through Certificates

	Collateral Report for September 25, 2003 Distribution


	Collateral Report


COLLATERAL								TOTAL
	Loan Count:
	*Original*							1045
	Prior							969
	Prefunding							-
	Scheduled Paid Offs							-
	Full Voluntary Prepayments							(14)
	Repurchases							(1)
	Liquidations							-
	Current							954

	*Principal Balance:*
	Original							349,999,381.33
	Prior							318,978,975.97
	Prefunding							-
	Scheduled Principal							(302,467.79)
	Partial and Full Voluntary Prepayments							(6,524,240.40)
	Repurchases							(447,137.76)
	Liquidations							-
	Current							311,705,130.02

PREFUNDING								TOTAL

	Remaining Pre-Funding Amount							0.00




Current Prin Balance by Groups (in millions of dollars)					Total Current Principal Balance (in millions of dollars)


				Page 8 of 21				© COPYRIGHT 2003 Deutsche Bank
	IndyMac Residential Asset Securitization Trust 2003-A4
	Mortgage Pass-Through Certificates

	Collateral Report for September 25, 2003 Distribution


	Collateral Report


CHARACTERISTICS								TOTAL

	Weighted Average Coupon Original							6.434559%
	Weighted Average Coupon Prior							6.426454%
	Weighted Average Coupon Current							6.425657%
	Weighted Average Months to Maturity Original							357
	Weighted Average Months to Maturity Prior							353
	Weighted Average Months to Maturity Current							352
	Weighted Avg Remaining Amortization Term Original							-
	Weighted Avg Remaining Amortization Term Prior							-
	Weighted Avg Remaining Amortization Term Current							-
	Weighted Average Seasoning Original							2.54
	Weighted Average Seasoning Prior							6.15
	Weighted Average Seasoning Current							6.88

Note: Original information refers to deal issue.




WAC by Groups					Total WAC


WARAT by Groups					Total WARAT


Note: Dates correspond to distribution dates.
				Page 9 of 21				© COPYRIGHT 2003 Deutsche Bank
	IndyMac Residential Asset Securitization Trust 2003-A4
	Mortgage Pass-Through Certificates

	Collateral Report for September 25, 2003 Distribution


	Collateral Report


ARM CHARACTERISTICS								TOTAL

	Weighted Average Margin Original							0.000%
	Weighted Average Margin Prior							0.000%
	Weighted Average Margin Current							0.000%
	Weighted Average Max Rate Original							0.000%
	Weighted Average Max Rate Prior							0.000%
	Weighted Average Max Rate Current							0.000%
	Weighted Average Min Rate Original							0.000%
	Weighted Average Min Rate Prior							0.000%
	Weighted Average Min Rate Current							0.000%
	Weighted Average Cap Up Original							0.000%
	Weighted Average Cap Up Prior							0.000%
	Weighted Average Cap Up Current							0.000%
	Weighted Average Cap Down Original							0.000%
	Weighted Average Cap Down Prior							0.000%
	Weighted Average Cap Down Current							0.000%

Note: Original information refers to deal issue.

SERVICING FEES / ADVANCES								TOTAL

	Current PPIS							9,988.49
	Current Net PPIS							0.00
	Delinquent Servicing Fees							1,327.24
	TOTAL SERVICING FEES							80,988.47
	TOTAL ADVANCES FOR CURRENT PERIOD							33,232.60


ADDITIONAL COLLATERAL INFORMATION								TOTAL

	Net Mortgage Rate							6.113478%


				Page 10 of 21				© COPYRIGHT 2003 Deutsche Bank
	IndyMac Residential Asset Securitization Trust 2003-A4
	Mortgage Pass-Through Certificates

	Delinquency Report for September 25, 2003 Distribution


	Delinquency Report - Total


				<1 PAYMENT	1 PAYMENT	2 PAYMENTS	3+ PAYMENTS	TOTAL
DELINQUENT		Balance		-	2,852,034.76	84,785.74	1,101,883.54	4,038,704.04
		% Balance			0.91%	0.03%	0.35%	1.30%
		# Loans			11	1	6	18
		% # Loans			1.15%	0.10%	0.63%	1.89%
FORECLOSURE		Balance		-	-	-	1,018,230.32	1,018,230.32
		% Balance		0.00%	0.00%	0.00%	0.33%	0.33%
		# Loans		-	-	-	3	3
		% # Loans		0.00%	0.00%	0.00%	0.31%	0.31%
BANKRUPTCY		Balance		-	-	-	-	-
		% Balance		0.00%	0.00%	0.00%	0.00%	0.00%
		# Loans		-	-	-	-	-
		% # Loans		0.00%	0.00%	0.00%	0.00%	0.00%
REO		Balance		-	-	-	-	-
		% Balance		0.00%	0.00%	0.00%	0.00%	0.00%
		# Loans		-	-	-	-	-
		% # Loans		0.00%	0.00%	0.00%	0.00%	0.00%

TOTAL		Balance		-	2,852,034.76	84,785.74	2,120,113.86	5,056,934.36
		% Balance		0.00%	0.91%	0.03%	0.68%	1.62%
		# Loans		-	11	1	9	21
		% # Loans		0.00%	1.15%	0.10%	0.94%	2.20%
Note: <1 Payment = 1-30days, 1 Payment = 31-60days, 2 Payments = 61-90days, 3+ Payments = 91+
								6 Months Moving Average
1 or 2 Payments Delinquent					3 or More Payments Delinquent


Total Foreclosure					Total Bankruptcy and REO


Note: Dates correspond to distribution dates.
				Page 11 of 21				© COPYRIGHT 2003 Deutsche Bank
	IndyMac Residential Asset Securitization Trust 2003-A4
	Mortgage Pass-Through Certificates

	REO Report for September 25, 2003 Distribution


	REO Report - Mortgage Loans that Become REO During Current Distribution


SUMMARY				LOAN GROUP

Total Loan Count = 0				Loan Group 1 = Group I Group; REO Book Value = 000.00
Total Original Principal Balance = 000.00
Total Current Balance = 000.00
REO Book Value = 000.00

REO Book Value reported corresponds to total REO loans, including loans that become REO during current distribution.

Loan Number		Original	Stated		Current	State &
&		Principal	Principal	Paid to	Note	LTV at	Original	Origination
Loan Group		Balance	Balance	Date	Rate	Origination	Term	Date
SPACE INTENTIONALLY LEFT BLANK


				Page 12 of 21				© COPYRIGHT 2003 Deutsche Bank
	IndyMac Residential Asset Securitization Trust 2003-A4
	Mortgage Pass-Through Certificates

	Prepayment Report for September 25, 2003 Distribution


	Prepayment Report - Voluntary Prepayments


VOLUNTARY PREPAYMENTS								TOTAL

	*Current*
	Number of Paid in Full Loans							14
	Number of Repurchased Loans							1
	Total Number of Loans Prepaid in Full							15

	Paid in Full Balance							6,368,265.86
	Repurchased Loans Balance							447,137.76
	Curtailments Amount							155,974.54
	Total Prepayment Amount							6,971,378.16

	*Cumulative*
	Number of Paid in Full Loans							87
	Number of Repurchased Loans							4
	Total Number of Loans Prepaid in Full							91

	Paid in Full Balance							34,827,923.64
	Repurchased Loans Balance							1,310,351.50
	Curtailments Amount							252,676.89
	Total Prepayment Amount							36,390,952.03

SPACE INTENTIONALLY LEFT BLANK


Total Prepayments by Groups (in thousands of dollars)					Total Prepayments (in thousands of dollars)


				Page 13 of 21				© COPYRIGHT 2003 Deutsche Bank
	IndyMac Residential Asset Securitization Trust 2003-A4
	Mortgage Pass-Through Certificates

	Prepayment Report for September 25, 2003 Distribution


	Prepayment Report - Voluntary Prepayments


VOLUNTARY PREPAYMENT RATES								TOTAL

	SMM							2.19%
	3 Months Avg SMM							2.81%
	12 Months Avg SMM
	Avg SMM Since Cut-off							1.82%

	CPR							23.31%
	3 Months Avg CPR							29.00%
	12 Months Avg CPR
	Avg CPR Since Cut-off							19.79%

	PSA							1695.39%
	3 Months Avg PSA Approximation							2391.56%
	12 Months Avg PSA Approximation
	Avg PSA Since Cut-off Approximation							2086.25%







CPR by Groups					Total CPR


PSA by Groups					Total PSA


				Page 14 of 21				© COPYRIGHT 2003 Deutsche Bank
	IndyMac Residential Asset Securitization Trust 2003-A4
	Mortgage Pass-Through Certificates

	Prepayment Report for September 25, 2003 Distribution


	Prepayment Report - Voluntary Prepayments




CPR Avg since Cut-Off by Groups					Total CPR Avg since Cut-Off


PSA Avg since Cut-Off by Groups					Total PSA Avg since Cut-Off


PREPAYMENT CALCULATION METHODOLOGY
Single Monthly Mortality (SMM): (Voluntary partial and full prepayments + Repurchases)/(Beg Principal Balance - Sched Principal)
Conditional Prepayment Rate (CPR): 1-((1-SMM)^12)
PSA Standard Prepayment Model: CPR/(0.02*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/(0.02*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 and repurchases.
Dates correspond to distribution dates.

				Page 15 of 21				© COPYRIGHT 2003 Deutsche Bank


	IndyMac Residential Asset Securitization Trust 2003-A4
	Mortgage Pass-Through Certificates

	Prepayment Detail Report for September 25, 2003 Distribution


	Prepayment Detail Report - Loans Prepaid in Full During Current Distribution


SUMMARY						LOAN GROUP

Total Loan Count = 15						Loan Group 1 = Group I Group
Total Original Principal Balance = 6,949,270.00
Total Prepayment Amount = 6,815,403.62


Loan Number			Original			Current	State &	Type Prepayment
&		Loan	Principal	Prepayment	Prepayment	Note	LTV at	&	Origination
Loan Group		Status	Balance	Amount	Date	Rate	Origination	Original Term	Date

306438 1			980,000.00	922,983.32	Aug-22-03	7.500%	CA - 46.70%	Paid Off - 360	Mar-16-98
309314 1			235,000.00	215,092.64	Aug-15-03	7.250%	CA - 100.00%	Paid Off - 360	Mar-20-98
620733 1			516,800.00	484,412.72	Aug-29-03	7.000%	CA - 80.00%	Paid Off - 360	Apr-28-98
1953561 1			195,000.00	194,155.14	Aug-02-03	6.000%	CA - 32.50%	Paid Off - 360	Feb-27-03
2153607 1			175,920.00	174,929.25	Aug-28-03	6.375%	CA - 80.00%	Paid Off - 360	Jan-07-03
2192432 1			650,000.00	646,884.00	Aug-21-03	6.250%	CA - 72.22%	Paid Off - 360	Feb-13-03
2205669 1			650,000.00	646,627.10	Aug-15-03	6.000%	CA - 57.02%	Paid Off - 360	Feb-21-03
2215262 1			650,000.00	647,513.69	Aug-20-03	6.250%	CA - 50.00%	Paid Off - 360	Mar-05-03
2229573 1			500,000.00	497,482.97	Aug-25-03	6.000%	CA - 50.00%	Paid Off - 360	Feb-27-03
2240339 1			592,900.00	590,840.79	Aug-22-03	6.750%	CA - 70.00%	Paid Off - 360	Mar-15-03
2252173 1			126,850.00	126,185.40	Aug-26-03	6.750%	MD - 58.73%	Paid Off - 360	Dec-31-02
2262767 1			735,000.00	731,391.47	Aug-29-03	6.125%	UT - 66.82%	Paid Off - 360	May-22-02
2278587 1			385,000.00	383,455.38	Aug-26-03	6.000%	AZ - 71.96%	Paid Off - 360	Mar-05-03
2323727 1			106,800.00	106,311.99	Aug-02-03	6.500%	AZ - 75.00%	Paid Off - 360	Feb-24-03
2293181 1			450,000.00	447,137.76	Aug-31-03	8.000%	NJ - 60.65%	Repur/Subs - 360	Jan-29-03


					Page 16 of 21				© COPYRIGHT 2003 Deutsche Bank
	IndyMac Residential Asset Securitization Trust 2003-A4
	Mortgage Pass-Through Certificates

	Realized Loss Report for September 25, 2003 Distribution


	Realized Loss Report - Collateral


COLLATERAL REALIZED LOSSES								TOTAL

	*Current*
	Number of Loans Liquidated							-
	Collateral Realized Loss/(Gain) Amount							-
	Net Liquidation Proceeds							-

	*Cumulative*
	Number of Loans Liquidated							-
	Collateral Realized Loss/(Gain) Amount							-
	Net Liquidation Proceeds							-

	Note: Collateral Realized Loss Amount may include adjustments to loans liquidated in prior periods.

SPACE INTENTIONALLY LEFT BLANK


							3 Months Moving Average


Collateral Loss Severity Approximation by Groups					Collateral Loss Severity Approximation


				Page 17 of 21				© COPYRIGHT 2003 Deutsche Bank
	IndyMac Residential Asset Securitization Trust 2003-A4
	Mortgage Pass-Through Certificates

	Realized Loss Report for September 25, 2003 Distribution


	Realized Loss Report - Collateral


DEFAULT SPEEDS								TOTAL

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

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

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

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



CDR by Groups					Total CDR


SDA by Groups					Total SDA


				Page 18 of 21				© COPYRIGHT 2003 Deutsche Bank
	IndyMac Residential Asset Securitization Trust 2003-A4
	Mortgage Pass-Through Certificates

	Realized Loss Report for September 25, 2003 Distribution


	Realized Loss Report - Collateral




CDR Avg since Cut-Off by Groups					Total CDR Avg since Cut-Off


SDA Avg since Cut-Off by Groups					Total SDA Avg since Cut-Off


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 21				© COPYRIGHT 2003 Deutsche Bank


	IndyMac Residential Asset Securitization Trust 2003-A4
	Mortgage Pass-Through Certificates

	Realized Loss Detail Report for September 25, 2003 Distribution


	Realized Loss Detail Report - Loans Liquidated During Current Distribution


SUMMARY						LOAN GROUP

Total Loan Count = 0						Loan Group 1 = Group I Group
Total Original Principal Balance = 0.00
Total Prior Principal Balance = 0.00
Total Realized Loss Amount = 0.00
Total Net Liquidation Proceeds = 0.00
Note: Total Realized Loss Amount may include adjustments to loans liquidated in prior periods.

Loan Number			Original	Prior		Current	State &
&		Loan	Principal	Principal	Realized	Note	LTV at	Original	Origination
Loan Group		Status	Balance	Balance	Loss/(Gain)	Rate	Origination	Term	Date
SPACE INTENTIONALLY LEFT BLANK


					Page 20 of 21				© COPYRIGHT 2003 Deutsche Bank
	IndyMac Residential Asset Securitization Trust 2003-A4
	Mortgage Pass-Through Certificates

	Triggers, Adj. Rate Cert. and Miscellaneous Report for September 25, 2003 Distribution


	Triggers, Adj. Rate Cert. and Miscellaneous Report


TRIGGER EVENTS								TOTAL

	Senior Credit Depletion Date							No


ADJUSTABLE RATE CERTIFICATE INFORMATION								TOTAL
SPACE INTENTIONALLY LEFT BLANK


ADDITIONAL INFORMATION								TOTAL

	Senior Percentage							95.097607%
	Subordinate Percentage							4.902393%
	Senior Prepayment Percentage							100.000000%
	Subordinate Prepayment Percentage							0.000000%

	Current Special Hazard Loss Coverage Amount							3,855,108.88
	Current Fraud Loss Coverage Amount							3,500,000.00
	Current Bankruptcy Loss Coverage Amount							100,000.00


				Page 21 of 21				© COPYRIGHT 2003 Deutsche Bank

INDYMAC MBS INC RESIDENTIAL ASSET SECUR TRUST 2003-A4 8-K