
                                       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, 2005
                          (Date of earliest event reported)

            Indymac MBS, Inc. (as Depositor under the Pooling and Servicing
                Agreement, dated as NOvember 1, 2005, providing for the
               issuance of IndyMac INDX Mortgage Loan Trust 2005-AR31
                Mortgage Pass-Through Certificates, Series 2005-AR31)
                 (Exact name of registrant as specified in charter)


                                         DELAWARE
                     (State or Other Jurisdiction of Incorporation)

               333-127556-15                      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, 2005.

                                    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 29, 2005               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, 2005.



IndyMac INDX Mortgage Loan Trust 2005-AR31

Mortgage Pass-Through Certificates
Mortgage Pass-Through Certificates
2005-AR31

December 27, 2005 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					6
										2. Collection Account Report					6
										3. Collateral Report					11
										4. Delinquency Report					18
				Certificate Insurer(s)						5. REO Report					23
				Certificate Insurer(s)						5. REO Report					23
										6. Foreclosure Report					24

										7. Prepayment Report					25
										8. Prepayment Detail Report					30
										9. Realized Loss Report					31
										9. Realized Loss Report					31
										10. Realized Loss Detail Report					36
										11. Triggers and Adj. Cert. Report					37
				Servicer(s)						11. Triggers and Adj. Cert. Report					37
				Servicer(s)						12. Other Related Information					39
				IndyMac Bank						12. Other Related Information					39
				IndyMac Bank


				Underwriter(s)
				Deutsche Bank Securities


										Total Number of Pages					40
										Total Number of Pages

				Dates						Contacts

				Cut-Off Date:			November 01, 2005			Brent Hoyler
				Close Date:			November 29, 2005			Administrator
				First Distribution Date:			December 27, 2005			(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, 2005
										Factor Information:			(800) 735-7777
				Record Date:			November 30, 2005			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 40
IndyMac INDX Mortgage Loan Trust 2005-AR31

Mortgage Pass-Through Certificates
Mortgage Pass-Through Certificates
2005-AR31

December 27, 2005 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)

1-A-1	SR	$	74,350,000.00		74,350,000.00		322,763.95		1,368,117.29		1,690,881.24		0.00		0.00		72,981,882.71
1-A-1	SR	$	74,350,000.00		74,350,000.00		322,763.95		1,368,117.29		1,690,881.24		0.00		0.00		72,981,882.71
1-A-2	SR	$	18,587,000.00		18,587,000.00		80,688.82		342,020.12		422,708.94		0.00		0.00		18,244,979.88
2-A-1	SR	$	247,033,000.00		247,033,000.00		1,101,110.34		2,037,633.37		3,138,743.71		0.00		0.00		244,995,366.63
2-A-2	SR	$	27,448,000.00		27,448,000.00		122,345.10		226,402.79		348,747.89		0.00		0.00		27,221,597.21
3-A-1	SR	$	179,938,000.00		179,938,000.00		861,957.40		689,437.78		1,551,395.18		0.00		0.00		179,248,562.22
4-A-1	SR	$	79,206,000.00		79,206,000.00		355,599.67		460,622.95		816,222.62		0.00		0.00		78,745,377.05
4-A-2	SR	$	12,362,000.00		12,362,000.00		55,499.88		71,891.28		127,391.16		0.00		0.00		12,290,108.72
5-A-1	SR	$	265,115,000.00		265,115,000.00		927,902.50		1,985,410.97		2,913,313.47		0.00		0.00		263,129,589.03
5-A-2	SR	$	29,457,000.00		29,457,000.00		104,703.27		220,599.56		325,302.83		0.00		0.00		29,236,400.44
A-R	SR/RES	$	100.00		100.00		0.43		100.00		100.43		0.00		0.00		0.00
A-X	SR/EXE	$	336,616,000.00		336,616,000.00		584,638.74		0.00		584,638.74		0.00		0.00		336,616,000.00
B-1	SUB	$	27,529,000.00		27,529,000.00		93,644.48		15,591.90		109,236.38		0.00		0.00		27,513,408.10
B-2	SUB	$	14,515,000.00		14,515,000.00		51,995.96		8,221.02		60,216.98		0.00		0.00		14,506,778.98
B-3	SUB	$	8,009,000.00		8,009,000.00		38,281.09		4,536.15		42,817.24		0.00		0.00		8,004,463.85
B-4	SUB	$	7,508,000.00		7,508,000.00		35,886.43		4,252.39		40,138.82		0.00		0.00		7,503,747.61
B-5	SUB	$	6,006,000.00		6,006,000.00		28,707.23		3,401.68		32,108.91		0.00		0.00		6,002,598.32
B-6	SUB/NOF	$	4,004,538.00		4,004,538.00		19,140.72		2,268.09		21,408.81		0.01		0.00		4,002,269.90
P-1	SUB/NOF	$	100.00		100.00		0.00		0.00		0.00		0.00		0.00		100.00
P-2	SUB/NOF	$	100.00		100.00		0.00		0.00		0.00		0.00		0.00		100.00


Total			1,337,683,838.00		1,337,683,838.00		4,784,866.01		7,440,507.34		12,225,373.35		0.01		0.00		1,330,243,330.65
Total





Page 2 of 40
IndyMac INDX Mortgage Loan Trust 2005-AR31

Mortgage Pass-Through Certificates
Mortgage Pass-Through Certificates
2005-AR31

December 27, 2005 Distribution

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)
1-A-1	11/01/05		11/30/05		F-30/360		45660LV97		74,350,000.00		1,000.000000		4.341143		18.401040		22.742182	981.598960
1-A-2	11/01/05		11/30/05		F-30/360		45660LW21		18,587,000.00		1,000.000000		4.341143		18.401039		22.742182	981.598961
2-A-1	11/01/05		11/30/05		F-30/360		45660LW39		247,033,000.00		1,000.000000		4.457341		8.248426		12.705767	991.751574
2-A-2	11/01/05		11/30/05		F-30/360		45660LW47		27,448,000.00		1,000.000000		4.457341		8.248426		12.705767	991.751574
3-A-1	11/01/05		11/30/05		F-30/360		45660LW54		179,938,000.00		1,000.000000		4.790302		3.831530		8.621832	996.168470
4-A-1	11/01/05		11/30/05		F-30/360		45660LW70		79,206,000.00		1,000.000000		4.489555		5.815506		10.305060	994.184494
4-A-2	11/01/05		11/30/05		F-30/360		45660LW88		12,362,000.00		1,000.000000		4.489555		5.815506		10.305061	994.184494
5-A-1	11/29/05		12/26/05		A-Act/360		45660LW96		265,115,000.00		1,000.000000		3.500000		7.488867		10.988867	992.511133
5-A-2	11/29/05		12/26/05		A-Act/360		45660LX20		29,457,000.00		1,000.000000		3.554444		7.488867		11.043312	992.511133
A-R	11/01/05		11/30/05		F-30/360		45660LY45		100.00		1,000.000000		4.300000		1,000.000000		1,004.300000	0.000000
A-X	11/01/05		11/30/05		F-30/360		45660LX38		336,616,000.00		1,000.000000		1.736812		0.000000		1.736812	1,000.000000
B-1	11/29/05		12/24/05		A-30/360		45660LX46		27,529,000.00		1,000.000000		3.401667		0.566381		3.968048	999.433619
B-2	11/29/05		12/24/05		A-30/360		45660LX53		14,515,000.00		1,000.000000		3.582223		0.566381		4.148604	999.433619
B-3	11/01/05		11/30/05		F-30/360		45660LX61		8,009,000.00		1,000.000000		4.779759		0.566382		5.346141	999.433618
B-4	11/01/05		11/30/05		F-30/360		45660LX79		7,508,000.00		1,000.000000		4.779759		0.566381		5.346140	999.433619
B-5	11/01/05		11/30/05		F-30/360		45660LX87		6,006,000.00		1,000.000000		4.779759		0.566380		5.346139	999.433620
B-6	11/01/05		11/30/05		F-30/360		45660LX95		4,004,538.00		1,000.000000		4.779757		0.566380		5.346137	999.433618
P-1	11/01/05		11/30/05		F-30/360		45660LY29		100.00		1,000.000000		0.000000		0.000000		0.000000	1,000.000000
P-2	11/01/05		11/30/05		F-30/360		45660LY52		100.00		1,000.000000		0.000000		0.000000		0.000000	1,000.000000




Page 3 of 40
IndyMac INDX Mortgage Loan Trust 2005-AR31

Mortgage Pass-Through Certificates
Mortgage Pass-Through Certificates
2005-AR31

December 27, 2005 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)
1-A-1	74,350,000.00		322,763.95		1,345,094.07		23,023.22		1,368,117.29		1,690,881.24		0.00		0.00		72,981,882.71
1-A-2	18,587,000.00		80,688.82		1,345,094.07		23,023.22		342,020.12		422,708.94		0.00		0.00		18,244,979.88
2-A-1	247,033,000.00		1,101,110.34		2,003,343.27		34,290.10		2,037,633.37		3,138,743.71		0.00		0.00		244,995,366.63
2-A-2	27,448,000.00		122,345.10		2,003,343.27		34,290.10		226,402.79		348,747.89		0.00		0.00		27,221,597.21
3-A-1	179,938,000.00		861,957.40		677,835.65		11,602.13		689,437.78		1,551,395.18		0.00		0.00		179,248,562.22
4-A-1	79,206,000.00		355,599.67		452,871.40		7,751.55		460,622.95		816,222.62		0.00		0.00		78,745,377.05
4-A-2	12,362,000.00		55,499.88		70,681.47		1,209.81		71,891.28		127,391.16		0.00		0.00		12,290,108.72
5-A-1	265,115,000.00		927,902.50		1,951,999.69		33,411.28		1,985,410.97		2,913,313.47		0.00		0.00		263,129,589.03
5-A-2	29,457,000.00		104,703.27		216,887.22		3,712.34		220,599.56		325,302.83		0.00		0.00		29,236,400.44
A-R	100.00		0.43		98.32		1.68		100.00		100.43		0.00		0.00		0.00
A-X	336,616,000.00		584,638.74		0.00		0.00		0.00		584,638.74		0.00		0.00		336,616,000.00
B-1	27,529,000.00		93,644.48		15,329.51		262.39		15,591.90		109,236.38		0.00		0.00		27,513,408.10
B-2	14,515,000.00		51,995.96		8,082.67		138.35		8,221.02		60,216.98		0.00		0.00		14,506,778.98
B-3	8,009,000.00		38,281.09		4,459.81		76.34		4,536.15		42,817.24		0.00		0.00		8,004,463.85
B-4	7,508,000.00		35,886.43		4,180.83		71.56		4,252.39		40,138.82		0.00		0.00		7,503,747.61
B-5	6,006,000.00		28,707.23		3,344.44		57.24		3,401.68		32,108.91		0.00		0.00		6,002,598.32
B-6	4,004,538.00		19,140.72		2,229.92		38.17		2,268.09		21,408.81		0.01		0.00		4,002,269.90
P-1	100.00		0.00		0.00		0.00		0.00		0.00		0.00		0.00		100.00
P-2	100.00		0.00		0.00		0.00		0.00		0.00		0.00		0.00		100.00


Total	1,337,683,838.00		4,784,866.01		10,104,875.61		172,959.48		7,440,507.34		12,225,373.35		0.01		0.00		1,330,243,330.65



Page 4 of 40
IndyMac INDX Mortgage Loan Trust 2005-AR31

Mortgage Pass-Through Certificates
Mortgage Pass-Through Certificates
2005-AR31

December 27, 2005 Distribution

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)
1-A-1	5.20937%		74,350,000.00		322,763.95		0.00		0.00		0.00		322,763.95		322,763.95		0.00
1-A-2	5.20937%		18,587,000.00		80,688.82		0.00		0.00		0.00		80,688.82		80,688.82		0.00
2-A-1	5.34881%		247,033,000.00		1,101,110.34		0.00		0.00		0.00		1,101,110.34		1,101,110.34		0.00
2-A-2	5.34881%		27,448,000.00		122,345.10		0.00		0.00		0.00		122,345.10		122,345.10		0.00
3-A-1	5.74836%		179,938,000.00		861,957.40		0.00		0.00		0.00		861,957.40		861,957.40		0.00
4-A-1	5.38747%		79,206,000.00		355,599.67		0.00		0.00		0.00		355,599.67		355,599.67		0.00
4-A-2	5.38747%		12,362,000.00		55,499.88		0.00		0.00		0.00		55,499.88		55,499.88		0.00
5-A-1	4.50000%		265,115,000.00		927,902.50		0.00		0.00		0.00		927,902.50		927,902.50		0.00
5-A-2	4.57000%		29,457,000.00		104,703.27		0.00		0.00		0.00		104,703.27		104,703.27		0.00
A-R	5.16000%		100.00		0.43		0.00		0.00		0.00		0.43		0.43		0.00
A-X	2.08417%		336,616,000.00		584,638.74		0.00		0.00		0.00		584,638.74		584,638.74		0.00
B-1	4.71000%		27,529,000.00		93,644.48		0.00		0.00		0.00		93,644.48		93,644.48		0.00
B-2	4.96000%		14,515,000.00		51,995.96		0.00		0.00		0.00		51,995.96		51,995.96		0.00
B-3	5.73571%		8,009,000.00		38,281.09		0.00		0.00		0.00		38,281.09		38,281.09		0.00
B-4	5.73571%		7,508,000.00		35,886.43		0.00		0.00		0.00		35,886.43		35,886.43		0.00
B-5	5.73571%		6,006,000.00		28,707.23		0.00		0.00		0.00		28,707.23		28,707.23		0.00
B-6	5.73571%		4,004,538.00		19,140.72		0.00		0.00		0.00		19,140.72		19,140.72		0.00
P-1	0.00000%		100.00		0.00		0.00		0.00		0.00		0.00		0.00		0.00
P-2	0.00000%		100.00		0.00		0.00		0.00		0.00		0.00		0.00		0.00


Total			1,337,683,838.00		4,784,866.01		0.00		0.00		0.00		4,784,866.01		4,784,866.01		0.00



Page 5 of 40
IndyMac INDX Mortgage Loan Trust 2005-AR31

Mortgage Pass-Through Certificates
Mortgage Pass-Through Certificates
2005-AR31

December 27, 2005 Distribution
Collection Account Report
SUMMARY
SUMMARY
														Group 5
Principal Collections														2,207,997.85
Principal Withrawals														0.00
Principal Other Accounts														0.00
TOTAL NET PRINCIPAL														2,207,997.85
Interest Collections														1,709,188.39
Interest Withdrawals														-0.00
Interest Other Accounts														0.00
Interest Fees														-34,201.09
TOTAL NET INTEREST														1,674,987.31
TOTAL AVAILABLE FUNDS FOR DISTRIBUTION														3,882,985.16

SUMMARY
SUMMARY
						Group 4		Group 3		Group 2		Group 1		Total
Principal Collections						533,330.31		691,343.62		2,296,712.06		1,711,123.51		7,440,507.35
Principal Withrawals						0.00		0.00		0.00		0.00		0.00
Principal Other Accounts						0.00		0.00		0.00		0.00		0.00
TOTAL NET PRINCIPAL						533,330.31		691,343.62		2,296,712.06		1,711,123.51		7,440,507.35
Interest Collections						447,059.88		942,761.50		1,342,307.85		441,301.34		4,882,618.96
Interest Withdrawals						-0.00		-0.00		-0.00		-0.00		-0.00
Interest Other Accounts						0.00		0.00		0.00		0.00		0.00
Interest Fees						-6,202.84		-18,412.92		-30,293.44		-8,642.68		-97,752.96
TOTAL NET INTEREST						440,857.04		924,348.58		1,312,014.41		432,658.66		4,784,866.00
TOTAL AVAILABLE FUNDS FOR DISTRIBUTION						974,187.35		1,615,692.20		3,608,726.47		2,143,782.17		12,225,373.36





Page 6 of 40
IndyMac INDX Mortgage Loan Trust 2005-AR31

Mortgage Pass-Through Certificates
Mortgage Pass-Through Certificates
2005-AR31

December 27, 2005 Distribution

PRINCIPAL - COLLECTIONS
PRINCIPAL - COLLECTIONS
															Group 5
Scheduled Principal Received															29,441.56
Curtailments															252,374.56
Prepayments In Full															1,926,181.73
Repurchased/Substitutions															0.00
Liquidations															0.00
Insurance Principal															0.00
Other Additional Principal															0.00
Delinquent Principal															-20,990.14
Realized Losses															-0.00
Advanced Principal															20,990.14
TOTAL PRINCIPAL COLLECTED															2,207,997.85
PRINCIPAL - COLLECTIONS
PRINCIPAL - COLLECTIONS
							Group 4		Group 3		Group 2		Group 1		Total
Scheduled Principal Received							12,090.17		28,235.79		42,317.33		13,126.95		125,211.80
Curtailments							11,240.14		190,207.83		3,759.41		1,881.35		459,463.29
Prepayments In Full							510,000.00		472,900.00		1,808,854.33		1,696,115.21		6,414,051.27
Repurchased/Substitutions							0.00		0.00		441,780.99		0.00		441,780.99
Liquidations							0.00		0.00		0.00		0.00		0.00
Insurance Principal							0.00		0.00		0.00		0.00		0.00
Other Additional Principal							0.00		0.00		0.00		0.00		0.00
Delinquent Principal							-8,358.04		-22,308.16		-29,838.35		-7,244.03		-88,738.72
Realized Losses							-0.00		-0.00		-0.00		-0.00		-0.00
Advanced Principal							8,358.04		22,308.16		29,838.35		7,244.03		88,738.72
TOTAL PRINCIPAL COLLECTED							533,330.31		691,343.62		2,296,712.06		1,711,123.51		7,440,507.35


PRINCIPAL - WITHDRAWALS

SPACE INTENTIONALLY LEFT BLANK





Page 7 of 40
IndyMac INDX Mortgage Loan Trust 2005-AR31

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Mortgage Pass-Through Certificates
2005-AR31

December 27, 2005 Distribution

PRINCIPAL - OTHER ACCOUNTS
PRINCIPAL - OTHER ACCOUNTS
														Group 5
TOTAL PRINCIPAL OTHER ACCOUNTS														0.00

PRINCIPAL - OTHER ACCOUNTS
PRINCIPAL - OTHER ACCOUNTS
						Group 4		Group 3		Group 2		Group 1		Total
TOTAL PRINCIPAL OTHER ACCOUNTS						0.00		0.00		0.00		0.00		0.00



INTEREST - COLLECTIONS
INTEREST - COLLECTIONS
														Group 5
Scheduled Interest														1,774,231.01
Repurchased/Substitution Interest														0.00
Liquidation Interest														0.00
Insurance Interest														0.00
Other Additional Interest														0.00
Prepayment Interest Shortfalls														-4,222.73
Delinquent Interest														-1,171,342.75
Compensating Interest														4,222.73
Civil Relief Act Shortfalls														-0.00
Interest Advanced														1,106,300.13
TOTAL INTEREST COLLECTED														1,709,188.39
INTEREST - COLLECTIONS
INTEREST - COLLECTIONS
						Group 4		Group 3		Group 2		Group 1		Total
Scheduled Interest						471,707.00		984,970.96		1,402,539.72		463,969.98		5,097,418.67
Repurchased/Substitution Interest						0.00		0.00		1,949.36		0.00		1,949.36
Liquidation Interest						0.00		0.00		0.00		0.00		0.00
Insurance Interest						0.00		0.00		0.00		0.00		0.00
Other Additional Interest						0.00		0.00		0.00		0.00		0.00
Prepayment Interest Shortfalls						-701.25		-0.00		-701.58		-346.99		-5,972.55
Delinquent Interest						-378,274.63		-684,139.12		-948,473.86		-337,571.43		-3,519,801.79
Compensating Interest						701.25		0.00		701.58		346.99		5,972.54
Civil Relief Act Shortfalls						-0.00		-0.00		-0.00		-0.00		-0.00
Interest Advanced						353,627.51		641,929.66		886,292.62		314,902.79		3,303,052.71
TOTAL INTEREST COLLECTED						447,059.88		942,761.50		1,342,307.85		441,301.34		4,882,618.96




Page 8 of 40
IndyMac INDX Mortgage Loan Trust 2005-AR31

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Mortgage Pass-Through Certificates
2005-AR31

December 27, 2005 Distribution

INTEREST - WITHDRAWALS

SPACE INTENTIONALLY LEFT BLANK



INTEREST - OTHER ACCOUNTS
INTEREST - OTHER ACCOUNTS
														Group 5
Prepayment Charges
TOTAL INTEREST OTHER ACCOUNTS														0.00

INTEREST - OTHER ACCOUNTS
INTEREST - OTHER ACCOUNTS
						Group 4		Group 3		Group 2		Group 1		Total
Prepayment Charges														0.00
TOTAL INTEREST OTHER ACCOUNTS						0.00		0.00		0.00		0.00		0.00





Page 9 of 40
IndyMac INDX Mortgage Loan Trust 2005-AR31

Mortgage Pass-Through Certificates
Mortgage Pass-Through Certificates
2005-AR31

December 27, 2005 Distribution

INTEREST - FEES
INTEREST - FEES
														Group 5
Current Servicing Fees														33,674.59
Trustee Fees														526.49
TOTAL INTEREST FEES														34,201.09

INTEREST - FEES
INTEREST - FEES
						Group 4		Group 3		Group 2		Group 1		Total
Current Servicing Fees						6,039.18		18,091.31		29,802.86		8,476.58		96,084.53
Trustee Fees						163.66		321.60		490.58		166.11		1,668.45
TOTAL INTEREST FEES						6,202.84		18,412.92		30,293.44		8,642.68		97,752.96




Page 10 of 40
IndyMac INDX Mortgage Loan Trust 2005-AR31

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Mortgage Pass-Through Certificates
2005-AR31

December 27, 2005 Distribution
Collateral Report


COLLATERAL



															Group 5



Loan Count:


Original														1,260
Prior														1,260
Prefunding														0
Scheduled Paid Offs														-0
Full Voluntary Prepayments														-7
Repurchases														-0
Liquidations														-0
Current														1,253
Principal Balance:


Original														315,895,086.75
Prior														315,895,086.75
Prefunding														0.00
Scheduled Principal														-29,441.56
Partial Prepayments														-252,374.56
Full Voluntary Prepayments														-1,926,181.73
Repurchases														-0.00
Liquidations														-0.00
Current														313,687,088.90

COLLATERAL



							Group 4		Group 3		Group 2		Group 1		Total



Loan Count:
Loan Count:


Original						259		457		1,270		297		3,543
Prior						259		457		1,270		297		3,543
Prefunding						0		0		0		0		0
Scheduled Paid Offs						-0		-0		-0		-0		-0
Full Voluntary Prepayments						-1		-1		-7		-5		-21
Repurchases						-0		-0		-2		-0		-2
Liquidations						-0		-0		-0		-0		-0
Current						258		456		1,261		292		3,520
Principal Balance:


Original						98,196,162.14		192,962,477.39		294,349,116.81		99,664,694.60		1,001,067,537.69
Prior						98,196,162.14		192,962,477.39		294,349,116.81		99,664,694.60		1,001,067,537.69
Prefunding						0.00		0.00		0.00		0.00		0.00
Scheduled Principal						-12,090.17		-28,235.79		-42,317.33		-13,126.95		-125,211.80
Partial Prepayments						-11,240.14		-190,207.83		-3,759.41		-1,881.35		-459,463.29
Full Voluntary Prepayments						-510,000.00		-472,900.00		-1,808,854.33		-1,696,115.21		-6,414,051.27
Repurchases						-0.00		-0.00		-441,780.99		-0.00		-441,780.99
Liquidations						-0.00		-0.00		-0.00		-0.00		-0.00
Current						97,662,831.83		192,271,133.77		292,052,404.75		97,953,571.09		993,627,030.34







Page 11 of 40
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Mortgage Pass-Through Certificates
2005-AR31

December 27, 2005 Distribution

PREFUNDING

SPACE INTENTIONALLY LEFT BLANK







Page 12 of 40
IndyMac INDX Mortgage Loan Trust 2005-AR31

Mortgage Pass-Through Certificates
Mortgage Pass-Through Certificates
2005-AR31

December 27, 2005 Distribution

CHARACTERISTICS
CHARACTERISTICS
														Group 5
Weighted Average Coupon Original														6.73982%
Weighted Average Coupon Prior														6.73982%
Weighted Average Coupon Current														6.73982%
Weighted Average Months to Maturity Original														358
Weighted Average Months to Maturity Prior														358
Weighted Average Months to Maturity Current														358
Weighted Avg Remaining Amortization Term Original														358
Weighted Avg Remaining Amortization Term Prior														358
Weighted Avg Remaining Amortization Term Current														358
Weighted Average Seasoning Original														1.77
Weighted Average Seasoning Prior														1.77
Weighted Average Seasoning Current														1.77
CHARACTERISTICS
CHARACTERISTICS
						Group 4		Group 3		Group 2		Group 1		Total
Weighted Average Coupon Original						5.76447%		6.12536%		5.72581%		5.58637%		6.11272%
Weighted Average Coupon Prior						5.76447%		6.12536%		5.72581%		5.58637%		6.11272%
Weighted Average Coupon Current						5.76447%		6.12536%		5.72581%		5.58637%		6.11272%
Weighted Average Months to Maturity Original						358		358		357		357		358
Weighted Average Months to Maturity Prior						358		358		357		357		358
Weighted Average Months to Maturity Current						358		358		357		357		358
Weighted Avg Remaining Amortization Term Original						358		358		357		357		358
Weighted Avg Remaining Amortization Term Prior						358		358		357		357		358
Weighted Avg Remaining Amortization Term Current						358		358		357		357		358
Weighted Average Seasoning Original						1.77		2.20		2.96		2.63		2.29
Weighted Average Seasoning Prior						1.77		2.20		2.96		2.63		2.29
Weighted Average Seasoning Current						1.77		2.20		2.96		2.63		2.29





Page 13 of 40
IndyMac INDX Mortgage Loan Trust 2005-AR31

Mortgage Pass-Through Certificates
Mortgage Pass-Through Certificates
2005-AR31

December 27, 2005 Distribution






Page 14 of 40
IndyMac INDX Mortgage Loan Trust 2005-AR31

Mortgage Pass-Through Certificates
Mortgage Pass-Through Certificates
2005-AR31

December 27, 2005 Distribution

ARM CHARACTERISTICS
ARM CHARACTERISTICS
														Group 5
Weighted Average Margin Original														2.61762%
Weighted Average Margin Prior														2.61762%
Weighted Average Margin Current														2.61762%
Weighted Average Max Rate Original														12.42850%
Weighted Average Max Rate Prior														12.42850%
Weighted Average Max Rate Current														12.42850%
Weighted Average Min Rate Original														2.61762%
Weighted Average Min Rate Prior														2.61762%
Weighted Average Min Rate Current														2.61762%
Weighted Average Cap Up Original														1.47266%
Weighted Average Cap Up Prior														1.47266%
Weighted Average Cap Up Current														1.47266%
Weighted Average Cap Down Original														1.47266%
Weighted Average Cap Down Prior														1.47266%
Weighted Average Cap Down Current														1.47266%

ARM CHARACTERISTICS
ARM CHARACTERISTICS
						Group 4		Group 3		Group 2		Group 1		Total
Weighted Average Margin Original						2.61443%		2.59621%		2.48544%		2.55964%		2.56854%
Weighted Average Margin Prior						2.61443%		2.59621%		2.48544%		2.55964%		2.56854%
Weighted Average Margin Current						2.61443%		2.59621%		2.48544%		2.55964%		2.56854%
Weighted Average Max Rate Original						11.41738%		11.76985%		11.35789%		11.44536%		11.78968%
Weighted Average Max Rate Prior						11.41738%		11.76985%		11.35789%		11.44536%		11.78968%
Weighted Average Max Rate Current						11.41738%		11.76985%		11.35789%		11.44536%		11.78968%
Weighted Average Min Rate Original						2.61443%		2.59621%		2.48544%		2.55964%		2.56854%
Weighted Average Min Rate Prior						2.61443%		2.59621%		2.48544%		2.55964%		2.56854%
Weighted Average Min Rate Current						2.61443%		2.59621%		2.48544%		2.55964%		2.56854%
Weighted Average Cap Up Original						1.20293%		1.72758%		1.71954%		1.63031%		1.58363%
Weighted Average Cap Up Prior						1.20293%		1.72758%		1.71954%		1.63031%		1.58363%
Weighted Average Cap Up Current						1.20293%		1.72758%		1.71954%		1.63031%		1.58363%
Weighted Average Cap Down Original						1.20293%		1.72758%		1.71954%		1.63031%		1.58363%
Weighted Average Cap Down Prior						1.20293%		1.72758%		1.71954%		1.63031%		1.58363%
Weighted Average Cap Down Current						1.20293%		1.72758%		1.71954%		1.63031%		1.58363%





Page 15 of 40
IndyMac INDX Mortgage Loan Trust 2005-AR31

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Mortgage Pass-Through Certificates
2005-AR31

December 27, 2005 Distribution

SERVICING FEES & ADVANCES

															Group 5




Current Servicing Fees														33,674.59
Delinquent Servicing Fees														65,042.62
TOTAL SERVICING FEES														98,717.22


Total Servicing Fees														98,717.22
Compensating Interest														-4,222.73
Delinquent Servicing Fees														-65,042.62
COLLECTED SERVICING FEES														29,451.87


Total Advanced Interest														1,106,300.13
Total Advanced Principal														20,990.14
Aggregate Advances with respect to this Distribution														1,127,290.27

SERVICING FEES & ADVANCES
SERVICING FEES & ADVANCES

							Group 4		Group 3		Group 2		Group 1		Total




Current Servicing Fees						6,039.18		18,091.31		29,802.86		8,476.58		96,084.53
Delinquent Servicing Fees						24,647.12		42,209.46		62,181.24		22,668.64		216,749.08
TOTAL SERVICING FEES						30,686.30		60,300.78		91,984.10		31,145.22		312,833.62


Total Servicing Fees						30,686.30		60,300.78		91,984.10		31,145.22		312,833.62
Compensating Interest						-701.25		-0.00		-701.58		-346.99		-5,972.54
Delinquent Servicing Fees						-24,647.12		-42,209.46		-62,181.24		-22,668.64		-216,749.08
COLLECTED SERVICING FEES						5,337.94		18,091.31		29,101.29		8,129.59		90,112.00


Total Advanced Interest						353,627.51		641,929.66		886,292.62		314,902.79		3,303,052.71
Total Advanced Principal						8,358.04		22,308.16		29,838.35		7,244.03		88,738.72
Aggregate Advances with respect to this Distribution						361,985.55		664,237.82		916,130.97		322,146.82		3,391,791.43







Page 16 of 40
IndyMac INDX Mortgage Loan Trust 2005-AR31

Mortgage Pass-Through Certificates
Mortgage Pass-Through Certificates
2005-AR31

December 27, 2005 Distribution

ADDITIONAL COLLATERAL INFORMATION
														Group 5
Prepayment Interest Shortfall (PPIS)														4,222.73
Compensating Interest														-4,222.73
Net Prepayment Interest Shortfall (PPIS)														0.00
Weighted Average Net Mortgage Rate														6.362824%

ADDITIONAL COLLATERAL INFORMATION
						Group 4		Group 3		Group 2		Group 1		Total
Prepayment Interest Shortfall (PPIS)						701.25		0.00		701.58		346.99		5,972.55
Compensating Interest						-701.25		-0.00		-701.58		-346.99		-5,972.54
Net Prepayment Interest Shortfall (PPIS)						0.00		0.00		0.00		0.00		0.00
Weighted Average Net Mortgage Rate						5.387466%		5.748363%		5.348809%		5.209371%		5.735716%




Page 17 of 40
IndyMac INDX Mortgage Loan Trust 2005-AR31

Mortgage Pass-Through Certificates
Mortgage Pass-Through Certificates
2005-AR31

December 27, 2005 Distribution
Delinquency Report

	TOTAL
					< 1 PAYMENT		1 PAYMENT		2 PAYMENTS		3+ PAYMENTS		TOTAL
	DELINQUENT		Balance				2,160,384.99		0.00		0.00		2,160,384.99
			% Balance				0.22%		0.00%		0.00%		0.22%
			# Loans				7		0		0		7
			% # Loans				0.20%		0.00%		0.00%		0.20%
	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		500,800.00		0.00		0.00		0.00		500,800.00
			% Balance		0.05%		0.00%		0.00%		0.00%		0.05%
			# Loans		2		0		0		0		2
			% # Loans		0.06%		0.00%		0.00%		0.00%		0.06%
	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		500,800.00		2,160,384.99		0.00		0.00		2,661,184.99
			% Balance		0.05%		0.22%		0.00%		0.00%		0.27%
			# Loans		2		7		0		0		9
			% # Loans		0.06%		0.20%		0.00%		0.00%		0.26%








Page 18 of 40
IndyMac INDX Mortgage Loan Trust 2005-AR31

Mortgage Pass-Through Certificates
Mortgage Pass-Through Certificates
2005-AR31

December 27, 2005 Distribution


	GROUP 1
					< 1 PAYMENT		1 PAYMENT		2 PAYMENTS		3+ PAYMENTS		TOTAL
	DELINQUENT		Balance				196,000.00		0.00		0.00		196,000.00
			% Balance				0.20%		0.00%		0.00%		0.20%
			# Loans				1		0		0		1
			% # Loans				0.34%		0.00%		0.00%		0.34%
	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		196,000.00		0.00		0.00		196,000.00
			% Balance		0.00%		0.20%		0.00%		0.00%		0.20%
			# Loans		0		1		0		0		1
			% # Loans		0.00%		0.34%		0.00%		0.00%		0.34%










Page 19 of 40
IndyMac INDX Mortgage Loan Trust 2005-AR31

Mortgage Pass-Through Certificates
Mortgage Pass-Through Certificates
2005-AR31

December 27, 2005 Distribution

	GROUP 2
					< 1 PAYMENT		1 PAYMENT		2 PAYMENTS		3+ PAYMENTS		TOTAL
	DELINQUENT		Balance				801,384.99		0.00		0.00		801,384.99
			% Balance				0.27%		0.00%		0.00%		0.27%
			# Loans				4		0		0		4
			% # Loans				0.32%		0.00%		0.00%		0.32%
	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		500,800.00		0.00		0.00		0.00		500,800.00
			% Balance		0.17%		0.00%		0.00%		0.00%		0.17%
			# Loans		2		0		0		0		2
			% # Loans		0.16%		0.00%		0.00%		0.00%		0.16%
	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		500,800.00		801,384.99		0.00		0.00		1,302,184.99
			% Balance		0.17%		0.27%		0.00%		0.00%		0.45%
			# Loans		2		4		0		0		6
			% # Loans		0.16%		0.32%		0.00%		0.00%		0.48%










Page 20 of 40
IndyMac INDX Mortgage Loan Trust 2005-AR31

Mortgage Pass-Through Certificates
Mortgage Pass-Through Certificates
2005-AR31

December 27, 2005 Distribution

	GROUP 3
					< 1 PAYMENT		1 PAYMENT		2 PAYMENTS		3+ PAYMENTS		TOTAL
	DELINQUENT		Balance				539,000.00		0.00		0.00		539,000.00
			% Balance				0.28%		0.00%		0.00%		0.28%
			# Loans				1		0		0		1
			% # Loans				0.22%		0.00%		0.00%		0.22%
	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		539,000.00		0.00		0.00		539,000.00
			% Balance		0.00%		0.28%		0.00%		0.00%		0.28%
			# Loans		0		1		0		0		1
			% # Loans		0.00%		0.22%		0.00%		0.00%		0.22%










Page 21 of 40
IndyMac INDX Mortgage Loan Trust 2005-AR31

Mortgage Pass-Through Certificates
Mortgage Pass-Through Certificates
2005-AR31

December 27, 2005 Distribution

	GROUP 4
					< 1 PAYMENT		1 PAYMENT		2 PAYMENTS		3+ PAYMENTS		TOTAL
	DELINQUENT		Balance				0.00		0.00		0.00		0.00
			% Balance				0.00%		0.00%		0.00%		0.00%
			# Loans				0		0		0		0
			% # Loans				0.00%		0.00%		0.00%		0.00%
	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		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%









Page 22 of 40
IndyMac INDX Mortgage Loan Trust 2005-AR31

Mortgage Pass-Through Certificates
Mortgage Pass-Through Certificates
2005-AR31

December 27, 2005 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




TOTAL


Page 23 of 40
IndyMac INDX Mortgage Loan Trust 2005-AR31

Mortgage Pass-Through Certificates
Mortgage Pass-Through Certificates
2005-AR31

December 27, 2005 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 24 of 40
IndyMac INDX Mortgage Loan Trust 2005-AR31

Mortgage Pass-Through Certificates
Mortgage Pass-Through Certificates
2005-AR31

December 27, 2005 Distribution
Prepayment Report

VOLUNTARY PREPAYMENTS
VOLUNTARY PREPAYMENTS

															Group 5




Current


Number of Paid in Full Loans														7
Number of Repurchased Loans														0
Total Number of Loans Prepaid in Full														7
Curtailments Amount														252,374.56
Paid in Full Balance														1,926,181.73
Repurchased Loans Balance														0.00
Total Prepayment Amount														2,178,556.29

Cumulative


Number of Paid in Full Loans														7
Number of Repurchased Loans														0
Total Number of Loans Prepaid in Full														7
Paid in Full Balance														1,926,181.73
Repurchased Loans Balance														0.00
Curtailments Amount														252,374.56
Total Prepayment Amount														2,178,556.29

VOLUNTARY PREPAYMENTS

							Group 4		Group 3		Group 2		Group 1		Total




Current


Number of Paid in Full Loans						1		1		7		5		21
Number of Repurchased Loans						0		0		2		0		2
Total Number of Loans Prepaid in Full						1		1		9		5		23
Curtailments Amount						11,240.14		190,207.83		3,759.41		1,881.35		459,463.29
Paid in Full Balance						510,000.00		472,900.00		1,808,854.33		1,696,115.21		6,414,051.27
Repurchased Loans Balance						0.00		0.00		441,780.99		0.00		441,780.99
Total Prepayment Amount						521,240.14		663,107.83		2,254,394.73		1,697,996.56		7,315,295.55

Cumulative


Number of Paid in Full Loans						1		1		7		5		21
Number of Repurchased Loans						0		0		2		0		2
Total Number of Loans Prepaid in Full						1		1		9		5		23
Paid in Full Balance						510,000.00		472,900.00		1,808,854.33		1,696,115.21		6,414,051.27
Repurchased Loans Balance						0.00		0.00		441,780.99		0.00		441,780.99
Curtailments Amount						11,240.14		190,207.83		3,759.41		1,881.35		459,463.29
Total Prepayment Amount						521,240.14		663,107.83		2,254,394.73		1,697,996.56		7,315,295.55





Page 25 of 40
IndyMac INDX Mortgage Loan Trust 2005-AR31

Mortgage Pass-Through Certificates
Mortgage Pass-Through Certificates
2005-AR31

December 27, 2005 Distribution






Page 26 of 40
IndyMac INDX Mortgage Loan Trust 2005-AR31

Mortgage Pass-Through Certificates
Mortgage Pass-Through Certificates
2005-AR31

December 27, 2005 Distribution

VOLUNTARY PREPAYMENTS RATES
VOLUNTARY PREPAYMENTS RATES

															Group 5



SMM														0.69%
3 Months Avg SMM														0.69%
12 Months Avg SMM														0.69%
Avg SMM Since Cut-off														0.69%


CPR														7.97%
3 Months Avg CPR														7.97%
12 Months Avg CPR														7.97%
Avg CPR Since Cut-off														7.97%


PSA														2,254.12%
3 Months Avg PSA Approximation														2,254.12%
12 Months Avg PSA Approximation														2,254.12%
Avg PSA Since Cut-off Approximation														2,254.12%

VOLUNTARY PREPAYMENTS RATES



							Group 4		Group 3		Group 2		Group 1		Total



SMM						0.53%		0.34%		0.77%		1.70%		0.73%
3 Months Avg SMM						0.53%		0.34%		0.77%		1.70%		0.73%
12 Months Avg SMM						0.53%		0.34%		0.77%		1.70%		0.73%
Avg SMM Since Cut-off						0.53%		0.34%		0.77%		1.70%		0.73%


CPR						6.19%		4.05%		8.81%		18.64%		8.43%
3 Months Avg CPR						6.19%		4.05%		8.81%		18.64%		8.43%
12 Months Avg CPR						6.19%		4.05%		8.81%		18.64%		8.43%
Avg CPR Since Cut-off						6.19%		4.05%		8.81%		18.64%		8.43%


PSA						1,744.47%		921.31%		1,488.07%		3,536.60%		1,841.59%
3 Months Avg PSA Approximation						1,744.47%		921.32%		1,488.06%		3,536.59%		1,841.59%
12 Months Avg PSA Approximation						1,744.47%		921.32%		1,488.06%		3,536.59%		1,841.59%
Avg PSA Since Cut-off Approximation						1,744.47%		921.32%		1,488.06%		3,536.59%		1,841.59%







Page 27 of 40
IndyMac INDX Mortgage Loan Trust 2005-AR31

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Mortgage Pass-Through Certificates
2005-AR31

December 27, 2005 Distribution











Page 28 of 40
IndyMac INDX Mortgage Loan Trust 2005-AR31

Mortgage Pass-Through Certificates
Mortgage Pass-Through Certificates
2005-AR31

December 27, 2005 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/(0.002min(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) Conditional Prepayment Rate (CPR): 1-((1-SMM)^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) Dates correspond to distribution dates. Note: Prepayment rates are calculated since deal issue date and include partial and full voluntary prepayments, liquidations, and repurchases.













Page 29 of 40
IndyMac INDX Mortgage Loan Trust 2005-AR31

Mortgage Pass-Through Certificates
Mortgage Pass-Through Certificates
2005-AR31

December 27, 2005 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

120396102 1			72,800.00		72,800.00			06-Dec-2005		5.250%		MO - 79.13%		Paid Off - 360		01-Jun-2005
120396102 1			72,800.00		72,800.00			06-Dec-2005		5.250%		MO - 79.13%		Paid Off - 360		01-Jun-2005
121666122 2			206,400.00		206,400.00			15-Dec-2005		5.875%		NV - 69.99%		Paid Off - 360		01-Aug-2005
121722844 2			335,947.00		335,947.00			29-Nov-2005		5.750%		CA - 80.00%		Paid Off - 360		01-Aug-2005
121723026 2			272,000.00		272,000.00			22-Nov-2005		6.000%		WA - 80.00%		Paid Off - 360		01-Aug-2005
121725530 2			353,000.00		353,000.00			02-Dec-2005		5.750%		CA - 78.44%		Paid Off - 360		01-Aug-2005
121727571 1			156,500.00		156,468.21			14-Dec-2005		4.875%		IL - 86.94%		Paid Off - 360		01-Aug-2005
121728049 2			264,200.00		264,200.00			05-Dec-2005		5.625%		CA - 80.00%		Paid Off - 360		01-Sep-2005
121728218 2			107,900.00		107,576.12			23-Nov-2005		6.000%		FL - 79.99%		Paid Off - 360		01-Sep-2005
121733868 5			209,600.00		208,500.06			06-Dec-2005		6.500%		IL - 80.00%		Paid Off - 360		01-Sep-2005
121735933 5			276,000.00		276,000.00			16-Nov-2005		6.500%		MD - 80.00%		Paid Off - 360		01-Oct-2005
121736725 5			393,600.00		393,600.00			04-Nov-2005		6.875%		CA - 80.00%		Paid Off - 360		01-Oct-2005
121738495 5			88,400.00		88,261.67			16-Nov-2005		7.250%		CA - 80.00%		Paid Off - 360		01-Oct-2005
121739517 1			100,000.00		100,000.00			16-Nov-2005		5.875%		OH - 62.50%		Paid Off - 360		01-Nov-2005
121771156 3			472,900.00		472,900.00			09-Dec-2005		5.500%		GA - 72.75%		Paid Off - 360		01-Nov-2005
121818662 2			270,000.00		269,731.21			29-Nov-2005		6.000%		IL - 50.00%		Paid Off - 360		01-Nov-2005
121918664 4			510,000.00		510,000.00			22-Nov-2005		5.875%		WA - 85.00%		Paid Off - 360		01-Nov-2005
121965130 1			981,247.00		981,247.00			01-Dec-2005		5.375%		CA - 59.47%		Paid Off - 360		01-Nov-2005
122159665 5			585,000.00		585,000.00			18-Nov-2005		6.750%		WA - 75.00%		Paid Off - 360		01-Dec-2005
122171334 1			385,600.00		385,600.00			29-Nov-2005		5.875%		FL - 80.00%		Paid Off - 360		01-Dec-2005
122209246 5			254,900.00		254,900.00			14-Dec-2005		7.500%		NV - 79.99%		Paid Off - 360		01-Nov-2005
122249520 5			119,920.00		119,920.00			07-Dec-2005		7.000%		WI - 80.00%		Paid Off - 360		01-Jan-2006
120396116 2			285,000.00		282,681.35			#######		5.250%		MN - 70.20%		Repur/Subs - 360		01-May-2005
121734874 2			159,100.00		159,099.64			30-Nov-2005		5.375%		AL - 74.00%		Repur/Subs - 360		01-Jun-2005


TOTAL			6,860,014.00		6,855,832.26
TOTAL


Page 30 of 40
IndyMac INDX Mortgage Loan Trust 2005-AR31

Mortgage Pass-Through Certificates
Mortgage Pass-Through Certificates
2005-AR31

December 27, 2005 Distribution
Realized Loss Report

COLLATERAL REALIZED LOSSES



															Group 5


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
		Fraud Loss Coverage Amt
		Bankruptcy Loss Coverage Amt

COLLATERAL REALIZED LOSSES



							Group 4		Group 3		Group 2		Group 1		Total


Current
Current



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

Cumulative
Cumulative



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





		Special Hazard Loss Coverage Amt														10,010,675.00
		Fraud Loss Coverage Amt														30,037,026.13
		Bankruptcy Loss Coverage Amt														0.00







Page 31 of 40
IndyMac INDX Mortgage Loan Trust 2005-AR31

Mortgage Pass-Through Certificates
Mortgage Pass-Through Certificates
2005-AR31

December 27, 2005 Distribution





Page 32 of 40
IndyMac INDX Mortgage Loan Trust 2005-AR31

Mortgage Pass-Through Certificates
Mortgage Pass-Through Certificates
2005-AR31

December 27, 2005 Distribution


DEFAULT SPEEDS



															Group 5



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%

DEFAULT SPEEDS



							Group 4		Group 3		Group 2		Group 1		Total



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


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


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


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








Page 33 of 40
IndyMac INDX Mortgage Loan Trust 2005-AR31

Mortgage Pass-Through Certificates
Mortgage Pass-Through Certificates
2005-AR31

December 27, 2005 Distribution








Page 34 of 40
IndyMac INDX Mortgage Loan Trust 2005-AR31

Mortgage Pass-Through Certificates
Mortgage Pass-Through Certificates
2005-AR31

December 27, 2005 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 35 of 40
IndyMac INDX Mortgage Loan Trust 2005-AR31

Mortgage Pass-Through Certificates
Mortgage Pass-Through Certificates
2005-AR31

December 27, 2005 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 36 of 40
IndyMac INDX Mortgage Loan Trust 2005-AR31

Mortgage Pass-Through Certificates
Mortgage Pass-Through Certificates
2005-AR31

December 27, 2005 Distribution
Triggers and Adj. Cert. Report
TRIGGER EVENTS
TRIGGER EVENTS
														Group 5
						Has Optional Termination Date Reached (0=No,1=Yes)
						Has Sr. Prepay Stepdown Condition Occurred
						Has Spl. Haz. Cov. Term. Date Occured (0=No,1=Yes)
						Has Fraud Loss Coverage Term. Date Occured
						Has Bankrpt Loss Cov. Term. Date Occured

TRIGGER EVENTS
TRIGGER EVENTS
						Group 4		Group 3		Group 2		Group 1		Total
						Has Optional Termination Date Reached (0=No,1=Yes)								No
						Has Sr. Prepay Stepdown Condition Occurred								No
						Has Spl. Haz. Cov. Term. Date Occured (0=No,1=Yes)								No
						Has Fraud Loss Coverage Term. Date Occured								No
						Has Bankrpt Loss Cov. Term. Date Occured								No



ADJUSTABLE RATE CERTIFICATE INFORMATION

SPACE INTENTIONALLY LEFT BLANK





Page 37 of 40
IndyMac INDX Mortgage Loan Trust 2005-AR31

Mortgage Pass-Through Certificates
Mortgage Pass-Through Certificates
2005-AR31

December 27, 2005 Distribution

ADDITIONAL INFORMATION
ADDITIONAL INFORMATION
														Group 5
Current Senior Percentage														93.249947%
Current Subordinate Percentage														6.750053%
Senior Prepayment Percentage														100.000000%
Subordinate Prepayment Percentage														0.000000%

ADDITIONAL INFORMATION
ADDITIONAL INFORMATION
						Group 4		Group 3		Group 2		Group 1		Total
Current Senior Percentage						93.250080%		93.250254%		93.250152%		93.249772%
Current Subordinate Percentage						6.749920%		6.749746%		6.749848%		6.750228%
Senior Prepayment Percentage						100.000000%		100.000000%		100.000000%		100.000000%
Subordinate Prepayment Percentage						0.000000%		0.000000%		0.000000%		0.000000%



Page 38 of 40
IndyMac INDX Mortgage Loan Trust 2005-AR31

Mortgage Pass-Through Certificates
Mortgage Pass-Through Certificates
2005-AR31

December 27, 2005 Distribution
Other Related Information
ADDITIONAL INFORMATION
ADDITIONAL INFORMATION
														Group 5


Sched. Payments for 60+Day Delinquent Loans														0.00
Sched. Pmts - 60+Day Delinquent Loans, 1 Month Prior														0.00
Sched. Pmts - 60+Day Delinquent Loans, 2 Month Prior														0.00
Sched. Pmts - 60+Day Delinquent Loans, 3 Month Prior														0.00
Sched. Pmts - 60+Day Delinquent Loans, 4 Month Prior														0.00
Sched. Pmts - 60+Day Delinquent Loans, 5 Month Prior														0.00
Sched. Pmts - 60+Day Delinquent Loans, 6 Month Prior														0.00
Sched. Pmts - 60+Day Delinquent Loans, 7 Month Prior														0.00
Sched. Pmts - 60+Day Delinquent Loans, 8 Month Prior														0.00
Sched. Pmts - 60+Day Delinquent Loans, 9 Month Prior														0.00
Sched. Pmts - 60+Day Delinquent Loans, 10 Month Prior														0.00
Sched. Pmts - 60+Day Delinquent Loans, 11 Month Prior														0.00



Class B-1 Writedown Amount
Class B-2 Writedown Amount
Class B-3 Writedown Amount
Class B-4 Writedown Amount
Class B-5 Writedown Amount
Class B-6 Writedown Amount



Page 39 of 40
IndyMac INDX Mortgage Loan Trust 2005-AR31

Mortgage Pass-Through Certificates
Mortgage Pass-Through Certificates
2005-AR31

December 27, 2005 Distribution

ADDITIONAL INFORMATION
ADDITIONAL INFORMATION
						Group 4		Group 3		Group 2		Group 1		Total


Sched. Payments for 60+Day Delinquent Loans						0.00		0.00		0.00		0.00		0.00
Sched. Pmts - 60+Day Delinquent Loans, 1 Month Prior						0.00		0.00		0.00		0.00		0.00
Sched. Pmts - 60+Day Delinquent Loans, 2 Month Prior						0.00		0.00		0.00		0.00		0.00
Sched. Pmts - 60+Day Delinquent Loans, 3 Month Prior						0.00		0.00		0.00		0.00		0.00
Sched. Pmts - 60+Day Delinquent Loans, 4 Month Prior						0.00		0.00		0.00		0.00		0.00
Sched. Pmts - 60+Day Delinquent Loans, 5 Month Prior						0.00		0.00		0.00		0.00		0.00
Sched. Pmts - 60+Day Delinquent Loans, 6 Month Prior						0.00		0.00		0.00		0.00		0.00
Sched. Pmts - 60+Day Delinquent Loans, 7 Month Prior						0.00		0.00		0.00		0.00		0.00
Sched. Pmts - 60+Day Delinquent Loans, 8 Month Prior						0.00		0.00		0.00		0.00		0.00
Sched. Pmts - 60+Day Delinquent Loans, 9 Month Prior						0.00		0.00		0.00		0.00		0.00
Sched. Pmts - 60+Day Delinquent Loans, 10 Month Prior						0.00		0.00		0.00		0.00		0.00
Sched. Pmts - 60+Day Delinquent Loans, 11 Month Prior						0.00		0.00		0.00		0.00		0.00



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														0.01




Page 40 of 40

IndyMac INDX Mortgage Loan Trust 2005-AR31 8-K