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 28, 2007

IndyMac IMJA Mortgage Loan Trust 2007-A4

(exact name of issuing entity)

Commission File Number of the issuing entity: 333-140726-22

IndyMac MBS, Inc.

(Exact name of the depositor as specified in its charter)

Commission File Number of the depositor: 333-140726

IndyMac Bank, F.S.B.

(Exact name of the sponsor as specified in its charter)

Delaware		95-4791925
(State or Other Jurisdiction		(I.R.S. Employer
of Incorporation)		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

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any following provisions (see General Instruction A.2. below):

o	Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

o	Soliciting material pursuant to Rule 14a-12(b) under the Exchange Act (17 CFR 240.14a-12(b))

o	Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

o	Pre-commencement communications pursuant to Rule 14e-4(c) under the Exchange Act (17 CFR 240.14e-4(c))

Section 8 Other Events

Item 8.01 Other Events.

On December 28, 2007, IndyMac MBS, Inc. (the “Company”) entered into a Pooling and Servicing Agreement dated as of December 1, 2007 (the “Pooling and Servicing Agreement”), by and among the Company, as depositor, IndyMac Bank, F.S.B. (“IndyMac”), as seller and as servicer, and Deutsche Bank National Trust Company, as trustee (the “Trustee”), providing for the issuance of the Company’s IndyMac IMJA Mortgage Loan Trust 2007-A4 (the “Issuing Entity”), Mortgage Pass-Through Certificates, Series 2007-A4 (the “Certificates”). The Pooling and Servicing Agreement is annexed hereto as Exhibit 4.1.

Section 9

Financial Statements and Exhibits

Item 9.01

Financial Statements and Exhibits.

(a)	Financial statements of businesses acquired.

Not applicable.

(b)	Pro forma financial information.

Not applicable.

(c)	Shell Company Transactions.

Not applicable.

(d)

Exhibits.

Exhibit No.

Description

4.1

The Pooling and Servicing Agreement, dated as of December 1, 2007, by and among the Company, IndyMac and the Trustee.

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.

INDYMAC MBS, INC.

By: /s/ Victor H. Woodworth

Victor H. Woodworth

Vice President

Dated: January 24, 2008

Exhibit Index

Exhibit

4.1

The Pooling and Servicing Agreement, dated as of December 1, 2007, by and among the Company, IndyMac and the Trustee.

IndyMac IMJA Mortgage Loan Trust 2007-A4 8-K