SECOND AMENDED FOURTH SUPPLEMENTAL INDENTURE

SECOND AMENDED FOURTH SUPPLEMENTAL INDENTURE (this “ Second Amended Fourth Supplemental Indenture ”), dated as of July 22, 2008, between SLM Corporation, a Delaware corporation (the “ Company ”), and Deutsche Bank Trust Company Americas, as trustee (the “ EdNotes Trustee ”), which amends the Amended Fourth Supplemental Indenture, dated as of December 17, 2004 (the “ Amended Fourth Supplemental Indenture ”), between the Company and the EdNotes Trustee, which amends the Fourth Supplemental Indenture, dated as of January 16, 2003 (the “ Fourth Supplemental Indenture ”), between the Company and the EdNotes Trustee, as consented to by JPMorgan Chase Bank, National Association (formerly known as The Chase Manhattan Bank), as the original trustee (the “ Original Trustee ”) for the EdNotes (defined below) under the Indenture, dated as of October 1, 2000 (the “ Base Indenture ”, together with this Second Amended Fourth Supplemental Indenture, the Amended Fourth Supplemental Indenture and the Fourth Supplemental Indenture, each as amended or supplemented, collectively the “ Indenture ”), between the Company and The Bank of New York, as successor to JPMorgan Chase Bank, National Association.

W I T N E S S E T H

WHEREAS, the Company executed and delivered the Base Indenture to provide for the future issuance of debentures, notes or other evidences of indebtedness of the Company to be issued from time to time in one or more series as might be determined by the Company under the Indenture, in an unlimited aggregate principal amount which may be authenticated and delivered as provided in the Base Indenture;

WHEREAS, pursuant to the terms of the Base Indenture, the Company established a series of senior unsecured and unsubordinated notes known as the Medium Term Notes of the Company, Series B, due nine months or longer from the date of issue, otherwise known as EdNotes® (the “ EdNotes ”) on January 23, 2003; the form and substance of the EdNotes and the terms, provisions and conditions of the EdNotes to be set forth in an officers’ certificate under Section 2.02 of the Base Indenture;

WHEREAS, the Company (i) has filed with the Securities and Exchange Commission (A) a Prospectus and a Prospectus Supplement, each dated January 23, 2003, to Registration Statement (File No. 333-90316) with respect to an offering of up to $2,000,000,000 of the EdNotes, (B) a Prospectus and a Prospectus Supplement, each dated January 5, 2005, to Registration Statement (File No. 333-107132) with respect to an offering of up to $3,000,000,000 of the EdNotes, and (C) a Registration Statement (File No. 333-130584) under the Securities Act including a Prospectus dated July 22, 2008 containing a general description of the debt securities that the Company may offer from time to time, and (ii) will file with the Securities and Exchange Commission a Prospectus Supplement to Registration Statement (File No. 333-130584) with respect to an unlimited aggregate principal amount of EdNotes;

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WHEREAS, the Company desires to increase the aggregate principal amount of EdNotes that may be issued from time to time from $3,000,000,000 to an unlimited aggregate principal amount of EdNotes;

WHEREAS, the Company may file additional prospectuses and prospectus supplements to an effective registration statement or registration statements with respect to additional offerings of the EdNotes in the future;

WHEREAS, the Company and the EdNotes Trustee hereby amend the Fourth Supplemental Indenture by this Second Amended Fourth Supplemental Indenture; and

WHEREAS, all requirements necessary to make this Second Amended Fourth Supplemental Indenture a valid instrument in accordance with its terms have been performed, and the execution and delivery of this Second Amended Fourth Supplemental Indenture have been duly authorized in all respects.

NOW, THEREFORE, in consideration of the foregoing and for other good and valuable consideration, the receipt and sufficiency of which is hereby acknowledged, the Company and the EdNotes Trustee mutually covena