SECURITIES AND EXCHANGE COMMISSION

POST-EFFECTIVE

REGISTRATION STATEMENT

SLM CORPORATION

Robert S. Lavet, Esq.

Copy to:

Diana de Brito, Esq.

      Approximate date of commencement of proposed sale to public: From time to time after this registration statement becomes effective.

      If the only securities being registered on this form are being offered pursuant to dividend or interest reinvestment plans, please check the following box.     o

      If any of the securities being registered on this form are to be offered on a delayed or continuous basis pursuant to Rule 415 under the Securities Act of 1933, other than securities offered only in connection with dividend or interest reinvestment plans, check the following box.     þ

      If this form is filed to register additional securities for an offering pursuant to Rule 462(b) under the Securities Act, please check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering:     o                           

      If this form is a post-effective amendment filed pursuant to Rule 462(c) under the Securities Act, check the following box and list the Securities Act registration statement number of the earlier effective registration statement for
the same offering:     o                           

      If the delivery of the prospectus is expected to be made pursuant to Rule 434, please check the following box.     o

      The registrant hereby amends this registration statement on such date or dates as may be necessary to delay its effective date until the registrant shall file a further amendment which specifically states that this registration statement shall thereafter become effective in accordance with Section 8(a) of the Securities Act of 1933 or until the registration statement shall become effective on such date as the Commission, acting pursuant to said Section 8(a), may determine.

Filed Pursuant to 424(b)5

Prospectus

          We issued $2,000,000,000 original principal amount of the debentures on May 20, 2003 in a private placement. This prospectus will be used by the selling securityholders named in this prospectus or in amendments to this prospectus to resell from time to time the debentures and any shares of our common stock issuable upon conversion of the debentures.

      The following describes some of the terms of the debentures:

      The selling securityholders may sell all or a portion of the debentures or common stock in market transactions, negotiated transactions or otherwise and at prices which will be determined by the prevailing market or negotiated price. The selling securityholders also may sell all or a portion of the shares of common stock from time to time on the New York Stock Exchange. The selling securityholders will receive all of the proceeds from the sale of the debentures and the common stock.

      Our common stock is listed on the New York Stock Exchange under the symbol “SLM.”

      Investing in the debentures involves risks. See “Risk Factors Relating to the Debentures” beginning on page 6.

       Obligations of SLM Corporation and any subsidiary of SLM Corporation are not guaranteed by the full faith and credit of the United States of America. Neither SLM Corporation nor any subsidiary of SLM Corporation (other than Student Loan Marketing Association) is a government-sponsored enterprise or an instrumentality of the United States of America.

       Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of these securities or determined if this prospectus is truthful or complete. Any representation to the contrary is a criminal offense.

      The date of this prospectus is                     , 2004

TABLE OF CONTENTS

      This prospectus is part of a registration statement we filed with the SEC using a “shelf” registration process. You should rely only on the information contained or incorporated by reference in this prospectus. We have not authorized any other person to provide you with different information. If anyone provides you with different or inconsistent information, you should not rely on it. You should assume that the information appearing in this prospectus or any documents incorporated by reference is accurate only as of the date on the front cover of the applicable document. Our business, financial condition, results of operations and prospects may have changed since that date.

      This prospectus is based on information provided by us and by other sources that we believe are reliable. We cannot assure you that any information provided by other sources is accurate or complete. This prospectus summarizes documents and other information, and we refer you to them for a more complete understanding of what we discuss in this prospectus. In making an investment decision, you must rely on your own examination of our company and the terms of this offering and the debentures, including the merits and risks involved.

      We are not making any representation to any purchaser of the debentures regarding the legality of an investment in the debentures by such purchaser under any legal investment or similar laws or regulations. You should not consider any information in this prospectus to be legal, business or tax advice. You should consult your own attorney, business advisor and tax advisor for legal, business and tax advice regarding an investment in the debentures.

      References in this prospectus to “we,” “us,” “our” and “SLM” refer to SLM Corporation, a Delaware corporation, unless the context otherwise requires.

WHERE YOU CAN FIND MORE INFORMATION

      We file annual and quarterly reports, proxy statements and other information with the SEC. You may read and copy any of these documents at the SEC’s public facilities in Washington, D.C. located at 450 Fifth Street, N.W., Washington, D.C. 20549. Please call the SEC at 1-800-SEC-0330 for further information about the public reference room. The SEC also maintains a site on the World Wide Web at http://www.sec.gov. This site contains reports, proxy and information statements and other information about registrants that file electronically with the SEC. You can also inspect reports and other information we file at the office of the New York Stock Exchange, Inc. located at 20 Broad Street, New York, New York 10005 or at our web site at http://www.salliemae.com.

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INCORPORATION OF DOCUMENTS BY REFERENCE

      We are “incorporating by reference” into this prospectus some of the documents that we file with the SEC, which means that we are disclosing important information to you by referring you to those documents. The information incorporated by reference is deemed to be part of this prospectus, except for any information superseded by information contained directly in this prospectus or in any subsequently filed document that is incorporated by reference. The documents we are incorporating by reference into this prospectus contain important information about us and our finances. Specifically, we incorporate by reference:

      All documents that we file with the SEC pursuant to Section 13(a), 13(c), 14 or 15(d) of the Securities Exchange Act of 1934, as amended, from the date of this prospectus to the end of the offering under this prospectus are also deemed to be incorporated herein by reference and automatically will update information included in or previously incorporated by reference in this prospectus.

      You may request a copy of these filings, at no cost, by writing or calling us at the following address or telephone number:

Corporate Secretary

      Exhibits to the filings will not be sent, however, unless those exhibits have specifically been incorporated by reference in that filing.

      Information contained on our website is not intended to be incorporated by reference in this prospectus and you should not consider that information a part of this prospectus.

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FORWARD-LOOKING STATEMENTS

      This prospectus and the information incorporated by reference in this prospectus include forward-looking statements within the meaning of Section 27A of the Securities Act and Section 21E of the Exchange Act. These forward-looking statements are based on our management’s beliefs and assumptions and on information currently available to our management. Forward-looking statements include information concerning our possible or assumed future results of operations and statements preceded by, followed by or that include the words “believes,” “expects,” “anticipates,” “intends,” “plans,” “estimates” or similar expressions.

      Forward-looking statements involve risks, uncertainties and assumptions. Actual results may differ materially from those expressed in these forward-looking statements. You should not put undue reliance on any forward-looking statements. Except as required by law, we do not have any intention or obligation to update forward-looking statements after we distribute this prospectus.

      You should understand that the following important factors, among other things, could cause our results to differ materially from those expressed in forward-looking statements:

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SUMMARY

      The following summary is qualified in its entirety by the more detailed information included elsewhere or incorporated by reference in this prospectus. Because this is a summary, it may not contain all the information that is important to you. You should read the entire prospectus, as well as the information incorporated by reference, before making an investment decision.

SLM Corporation

      SLM Corporation and its subsidiaries are the nation’s leading private source of funding, servicing and support for higher education loans for students and their parents. We presently conduct a majority of our business through two wholly owned entities: the Student Loan Marketing Association, a government-sponsored enterprise chartered by an act of Congress, and Sallie Mae Servicing L.P., a Delaware limited partnership. The Student Loan Marketing Association must be liquidated by September 30, 2008, except under very limited circumstances. We intend to wind down the Student Loan Marketing Association by September 30, 2006.

      We derive most of our income from interest earnings or “spread income” from our portfolio of student loans. As we have grown our business, fee income from loan and guarantee servicing and other operations such as debt management operations has become an increasingly important source of earnings. We changed our name from USA Education, Inc. to SLM Corporation, effective May 17, 2002.

      Our principal executive offices are located at 12061 Bluemont Way, Reston, VA 20190, and our telephone number is (703) 810-3000.

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RISK FACTORS RELATING TO THE DEBENTURES

      Your investment in the debentures involves risks. You should carefully consider the following risks, as well as the other information included or incorporated by reference in this prospectus, before investing in the debentures.

Your right to receive payments on these debentures will be effectively subordinated to the rights of any future secured creditors. The debentures, in other circumstances, may effectively be subordinated to any existing and future liabilities of us or our subsidiaries.

      The debentures represent unsecured obligations of SLM Corporation. Accordingly, holders of any future secured indebtedness will have claims that are superior to your claims as holders of the debentures to the extent of the value of the assets securing that other indebtedness. In the event of any distribution or payment of our assets in any foreclosure, dissolution, winding-up, liquidation, reorganization, or other bankruptcy proceeding, holders of secured indebtedness will have a superior claim to those of our assets that constitute their collateral. In any of the foregoing events, we cannot assure you that there will be sufficient assets to pay amounts due on the debentures. Holders of the debentures will participate ratably with all holders of our unsecured indebtedness that ranks equally in right of payment with the debentures, and potentially with all of our other general creditors, based upon the respective amounts owed to each holder or creditor, in our remaining assets. As a result, holders of debentures may receive less, ratably, than holders of secured indebtedness.

      The Student Loan Marketing Association may pay dividends to us so long as at the time of the declaration of such dividends, after giving effect to the payment of such dividends as of the date of the declaration, the Student Loan Marketing Association’s capital would be in compliance with a minimum statutory capital adequacy ratio as well as a supplementary risk-based capital formula.

      Furthermore, if we fail to deliver our common stock upon conversion of a debenture and thereafter become the subject of bankruptcy proceedings, a holder’s claim for damages arising from our failure could be subordinated to all of our existing and future obligations.

We may not be able to pay cash dividends in the future.

      On May 29, 2003 we doubled the dividend on our common stock from $0.25 per share to $0.51 per share. Any future cash dividends will depend upon our results of operations, financial conditions, cash requirements, the availability of a surplus and other factors, including the ability of our subsidiaries to make distributions to us, which ability, in the case of the Student Loan Marketing Association, is restricted in the manner described above.

We may not have the ability to purchase debentures at the option of the holders or upon a change in control or to raise the funds necessary to finance the purchases.

      On July 25, 2007, 2011, 2015, 2019, 2023, 2027 and 2031 holders of the debentures may require us to purchase their debentures. However, it is possible that we would not have sufficient funds at that time to make the required purchase of debentures. We may be required to pay all or a portion of the purchase price in shares of our common stock, subject to satisfying the conditions in the indenture for making such payments. If we were unable to satisfy the conditions in the indenture to use shares of our common stock to pay the purchase price, we could be in default of our obligations on the debentures. In addition, if a holder requires us to purchase all or a portion of its debentures and we elect to deliver shares of our common stock, and we then become the subject of bankruptcy proceedings, a holder may not be able to rescind its notice obligating us to purchase all or a portion of its debentures, and a holder’s claim may be subordinated to all of our existing and future obligations.

      In addition, we will be required to offer to purchase all outstanding debentures if there is a failed remarketing. However, it is possible that we will not have sufficient funds available at any such time to make

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You should consider the U.S. federal income tax considerations of owning the debentures.

      The debentures will be treated as debt instruments subject to the U.S. federal income tax contingent payment debt regulations. You should be aware that, even if we do not pay any cash interest on the debentures, you will be required to include original issue discount in your gross income for U.S. federal income tax purposes. For U.S. federal income tax purposes, this original issue discount income will accrue from the original issue date of the debentures at the rate of 5.625% per year, compounded quarterly. U.S. holders will be required to accrue this original issue discount on a constant yield to maturity basis at this rate (subject to certain adjustments), with the result that a U.S. holder will recognize taxable income in excess of cash interest received while the debentures are outstanding.

      You will recognize gain or loss on the sale, exchange, conversion or retirement of a debenture in an amount equal to the difference between the amount realized on the sale, exchange, conversion or retirement, including the fair market value of any common stock received upon conversion or otherwise, and your adjusted tax basis in the debenture. Any gain recognized by you on the sale, exchange, conversion or retirement of a debenture generally will be ordinary interest income; any loss will generally be ordinary loss to the extent of the interest previously included in income and, thereafter, capital loss. See “Material U.S. Federal Income Tax Considerations.”

No active trading market exists for the debentures.

      There is currently no existing public market for the debentures. We do not intend to list the debentures on any national securities exchange or automated quotation system. We cannot assure you that an active or sustained trading market for the debentures will develop or that you will be able to sell your debentures. Although the initial purchasers in the offering made pursuant to Rule 144A under the Securities Act informed us that they intended to make a market in the debentures, such initial purchasers are not obligated to do so and may discontinue their market-making at any time without notice.

      Moreover, even if you are able to sell your debentures, we cannot assure you as to the price at which any sales will be made. Future trading prices of the debentures will depend on many factors, including, among other things, prevailing interest rates, our operating results, the price of our common stock and the market for similar securities. Historically, the market for convertible debt has been subject to disruptions that have caused volatility in prices. It is possible that the market for the debentures will be subject to disruptions which may have a negative effect on the debentures, regardless of our prospects or financial performance.

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USE OF PROCEEDS

      The selling securityholders will receive all of the net proceeds from the sale of the debentures or the shares of common stock sold under this prospectus. We will not receive any of such proceeds.

RATIO OF EARNINGS TO FIXED CHARGES

      The following table sets forth our ratio of earnings to fixed charges for the five years ended December 31, 2003 and the nine month period ended September 30, 2003 and September 30, 2004.

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PRICE RANGE AND DIVIDEND HISTORY OF OUR COMMON STOCK

      Our common stock is quoted on the New York Stock Exchange under the symbol “SLM.” On September 30, 2004, the last reported bid price of the common stock on the NYSE was $44.60 per share. The following table sets forth for the periods indicated below the high and low sale information for our common stock as listed on the NYSE, and dividends paid, for each quarterly period during the fiscal years 2001, 2002, 2003 and 2004.

      On May 15, 2003, our stockholders approved a proposal to increase the number of authorized shares of our common stock from 375,000,000 shares to 1,125,000,000 shares. In May 2003 the Board of Directors approved a three-for-one split of the Company’s stock to be effected in the form of a stock dividend. The additional shares of stock were distributed on June 20, 2003, to all shareholders of record on June 6, 2003.

      The share and per share information in this prospectus gives effect to the stock split.

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CAPITALIZATION

      The following table sets forth our capitalization at September 30, 2004 on an actual basis. You should read this table together with our financial statements and accompanying notes incorporated by reference in this prospectus. Amounts are in thousands, except share and per share amounts.

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DESCRIPTION OF DEBENTURES

      We issued the debentures under an indenture, dated as of May 20, 2003, between us and JPMorgan Chase Bank, as trustee.

      The following summary is not complete, and is subject to, and is qualified in its entirety by reference to, all of the provisions of the debentures and the indenture. We urge you to read the indenture and the form of the debentures, which you may obtain from us upon request, because they and not this description define your rights in respect of the debentures. As used in this description, all references to “SLM Corporation,” “SLM,” “we,” “us” or “our” mean SLM Corporation, excluding, unless otherwise expressly stated or the context otherwise requires, any of its subsidiaries.

General

      The debentures are limited to $2,000,000,000 aggregate original principal amount and are issued only in registered form without coupons in denominations of $1,000 original principal amount and any integral multiple of $1,000 above that amount. We use the term “debenture” in this prospectus to refer to each $1,000 original principal amount of debentures. The debentures will mature on July 25, 2035. On the maturity date of the debentures, a holder will receive the accreted principal amount of a debenture. The accreted principal amount will equal the original principal amount of $1,000 per debenture increased by a variable yield, which until July 25, 2007 will be 0% per annum and, unless a remarketing reset event occurs, commencing on July 25, 2007 will be reset quarterly to a rate of 3-month LIBOR minus .05% per annum. Regardless of the level of 3-month LIBOR, however, this yield will not be less than 0% per annum.

      The principal amount of the debentures will accrete daily beginning July 25, 2007 at the applicable yield, compounded quarterly. The yield will be calculated using the actual number of days elapsed from and including the LIBOR reset date, to but excluding the next succeeding LIBOR reset date, divided by 360 days. If a remarketing reset event occurs, the principal amount of the debentures will accrete daily at the yield described under “— Remarketing Reset Event” below, compounded quarterly. The rate of accretion will be applied to the accreted principal amount per debenture as of the day preceding the most recent yield reset date.

      The debentures bear regular interest at an annual rate equal to 3-month LIBOR, reset quarterly, minus .05% (but not less than 0%) on the original principal amount from May 20, 2003, or from the most recent date to which regular interest has been paid or provided for, until July 25, 2007 for all interest periods other than the initial interest period. For the initial interest period from and including May 20, 2003 to but excluding July 25, 2003, the regular interest rate on the debentures was 1.2487% per annum.

      Regular interest will be payable quarterly in arrears on January 25, April 25, July 25 and October 25 of each year, each an interest payment date, beginning July 25, 2003, to the person in whose name a debenture is registered at the close of business on the January 10, April 10, July 10 or October 10, as the case may be, immediately preceding the relevant interest payment date, each of which we refer to as a record date. Each payment of regular interest will include interest accrued for the period, which we refer to as an interest period, commencing on and including the immediately preceding interest payment date (or, if none, the original issuance date of the debentures) to but excluding the applicable interest payment date. Regular interest on the debentures will be computed using the actual number of days in the interest period divided by 360.

      From and after July 25, 2007, we will not pay regular interest. Contingent interest, if any, as described below under “— Contingent Interest,” will be payable in addition to the accreted principal amount.

      If any interest payment date (other than an interest payment date coinciding with the stated maturity date or earlier redemption date or purchase date) of a debenture falls on a day that is not a business day, such interest payment date will be postponed to the next succeeding business day, provided that, if such business day falls in the next succeeding calendar month, the interest payment date will be brought forward to the immediately preceding business day. If the stated maturity date, redemption date or purchase date of a debenture would fall on a day that is not a business day, the required payment of interest, if any, and

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      The debentures are redeemable prior to maturity only on or after July 25, 2007 and as described below under “— Redemption of Debentures at Our Option,” and do not have the benefit of a sinking fund. Principal of and interest on the debentures will be payable at the office of the paying agent, which initially will be JPMorgan Chase Bank. If certain conditions have been satisfied, the debentures may be presented for conversion at the office of the conversion agent, and for registration of transfer or exchange at the office of the registrar, each such agent initially being JPMorgan Chase Bank. No service charge will be made for any registration of transfer or exchange of debentures, but we may require payment of a sum sufficient to cover any tax or other governmental charge payable in connection therewith.

      Maturity, conversion, purchase by us at the option of a holder or redemption of a debenture will cause interest to cease to accrue on such debenture. We may not reissue a debenture that has matured or been converted, purchased by us at the option of a holder, redeemed or otherwise cancelled.

      The debentures are debt instruments subject to the contingent payment debt regulations. The debentures were issued with original issue discount for U.S. federal income tax purposes. Even if we do not pay any regular or contingent interest on the debentures, holders will be required to include accrued tax original issue discount in their gross income for U.S. federal income tax purposes. See “Material U.S. Federal Income Tax Considerations.”

      3-month LIBOR

      Prior to July 25, 2007, the annual rate of regular interest payable on the debentures will be reset on each interest payment date. Beginning on July 25, 2007, the yield on the debentures will be reset on each LIBOR reset date but no cash interest will be paid. We refer to each January 25, April 25, July 25 and October 25 as a LIBOR reset date. If any LIBOR reset date would otherwise be a day that is not a business day, that LIBOR reset date will be postponed to the next succeeding business day.

      As the calculation agent, we will determine 3-month LIBOR on the day that is two London and New York City business days before the related LIBOR reset date, which we refer to as the LIBOR determination date.

      “3-month LIBOR” means:

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      Interest on the debentures is calculated using an actual/360 accrual method, which means that interest will be calculated on the actual number of days elapsed in an interest period and an assumed year of 360 days.

      “Moneyline Telerate Page 3750” means the display on Moneyline Telerate (or any successor service) on such page (or any other page as may replace such page on such service) for the purpose of displaying the London interbank rates of major banks for United States dollars.

      “London business day” means a day on which commercial banks are open for business, including dealings in United States dollars, in London.

Ranking of Debentures

      The debentures are unsecured and unsubordinated obligations and rank equally in right of payment with all of our existing and future unsecured and unsubordinated indebtedness. The debentures are structurally subordinated to the indebtedness and liabilities of our subsidiaries, including existing and future indebtedness of Student Loan Marketing Association.

Conversion Rights

      A holder may convert debentures into common stock only if at least one of the conditions for conversion described below is satisfied. The ability to surrender debentures for conversion will expire at the close of business on the maturity date of the debentures, unless they have previously been redeemed or purchased. In addition, a holder may convert a debenture only until the close of business on the business day immediately preceding the redemption date if we call a debenture for redemption. A debenture for which a holder has delivered a purchase notice or a change in control purchase notice requiring us to purchase the debentures may be surrendered for conversion only if such notice is withdrawn in accordance with the indenture. If the debentures are remarketed the conditions to conversion must be satisfied thereafter or the debentures may not be converted.

      If the conditions for conversion are satisfied, a holder will receive 15.1572 shares of our common stock, subject to adjustment upon the occurrence of the events described below and upon the occurrence of any remarketing reset event. A holder of a debenture otherwise entitled to a fractional share will receive cash in an amount equal to the value of such fractional share based on the closing sale price of our common stock on the trading day immediately preceding the conversion date. Upon a conversion, we will have the right to deliver shares of our common stock, cash or a combination of cash and shares of our common stock, as described below. Notwithstanding the foregoing, in no event will the conversion rate exceed 26.5251 shares of our common stock per debenture, subject to anti-dilution adjustments, which we refer to as the maximum conversion rate.

      Conversion Rights Based on Common Stock Price. A holder may surrender debentures for conversion into shares of our common stock at any time after September 30, 2003 during a calendar quarter if the closing sale price of our common stock for at least 20 trading days in a period of 30 consecutive trading days ending on the last trading day of the preceding calendar quarter is more than 130% of the conversion price (initially 130% of $65.98, or $85.77) as of the last day of such calendar quarter. We refer to this as the “conversion trigger price.”

      “Trading day” means a day during which trading in securities generally occurs on the New York Stock Exchange or, if our common stock is not listed on the New York Stock Exchange, on the principal other national or regional securities exchange on which our common stock is then listed or, if our common stock is not listed on a national or regional securities exchange, on the National Association of Securities Dealers Automated Quotation System (“Nasdaq”) or, if our common stock is not quoted on the National Association of Securities Dealers Automated Quotation System, on the principal other market on which our common stock is then traded.

      The “closing sale price” of our common stock on any date means the closing sale price per share (or if no closing sale price is reported, the average of the closing bid and ask prices or, if more than one in either

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      The accreted principal amount of a debenture will be equal to the original principal amount of $1,000 per debenture increased daily by a variable yield, which until July 25, 2007 will be 0% per annum and, unless a remarketing reset event occurs, beginning on July 25, 2007, the yield will be reset quarterly on each LIBOR reset date to a rate of 3-month LIBOR minus .05% per annum, compounded quarterly, until a remarketing reset event occurs. Regardless of the level of 3-month LIBOR, however, this yield will never be less than 0% per annum. Because the conversion price of a debenture at any time is dependent upon the accreted principal amount of a debenture at that time, the conversion trigger price per share of our common stock, which is based on the conversion price, for periods ending after July 25, 2007 cannot be determined at this time. The following table indicates what the conversion trigger prices would be for the quarter ended September 30 of each year, beginning 2007, assuming the yield on the debentures was a constant 2.00%, 5.00% and 8.00% from July 25, 2007 to maturity. This table represents an example of only three possibilities, and you should realize that because LIBOR, and therefore the yield of the debentures, will fluctuate, the conversion price, and therefore the conversion trigger price, will differ, and may differ significantly, from the amounts shown below.

Hypothetical Conversion Trigger Prices

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      Conversion Rights Upon Credit Rating Events. During any period in which (1) the credit rating assigned to the debentures by S&P is below BBB+, (2) the credit rating assigned to the debentures by Moody’s is below Baa1, (3) the credit rating assigned to the debentures by Fitch is below BBB+ or (4) no credit rating is assigned to the debentures by any two of S&P, Moody’s and Fitch, holders may also surrender debentures for conversion into shares of our common stock. The debentures will cease to be convertible pursuant to this paragraph during any period or periods in which all of the credit ratings are increased above such levels.

      Conversion Upon Satisfaction of Trading Price Condition. Holders may surrender their debentures for conversion into our common stock prior to maturity during the five business day period after any five consecutive trading day period in which the “trading price” per debenture, as determined following a request by a holder of debentures in accordance with the procedures described below, for each day of that period was less than 98% of the product of the closing sale price of our common stock and the conversion rate (the “trading price condition”); provided that if, on the date of any conversion pursuant to the trading price condition that is on or after July 25, 2031, the closing sale price of our common stock is greater than the conversion price, then you will receive, in lieu of common stock based on the conversion rate, cash or common stock or a combination of cash and common stock, at our option, with a value equal to the accreted principal amount of your debentures plus accrued and unpaid interest, if any, including contingent interest, if any, as of the conversion date referred to as a “principal value conversion”. If you surrender your debentures for conversion and it is a principal value conversion, we will notify you by the second business day following the date of conversion that it is a principal value conversion and whether we will pay you all or a portion of the accreted principal amount plus accrued and unpaid interest, including contingent interest, if any, in cash, common stock or a combination of cash and common stock, and in what percentage. Any common stock delivered upon a principal value conversion will be valued at the greater of the conversion price on the conversion date and the average of the closing sale price of our common stock for a five trading day period starting the third trading day following the conversion date of the debentures. We will pay you any portion of the accreted principal amount plus accrued and unpaid interest to be paid in cash and deliver common stock with respect to any portion of the principal amount plus accrued and unpaid interest to be paid in common stock, no later than the third business day following the determination of the average stock price referred to above. The “conversion price” is, as of any date of determination, a dollar amount (initially $65.98) derived by dividing the accreted principal amount (initially $1,000) by the conversion rate then in effect.

      The “trading price” of the debentures on any date of determination means the average of the secondary market bid quotations obtained by the trustee for $10,000,000 original principal amount of the debentures at approximately 3:30 p.m., New York City time, on such determination date from three independent nationally recognized securities dealers we select; provided that if three such bids cannot reasonably be obtained by the trustee, but two such bids are obtained, then the average of the two bids shall be used, and if only one such bid can reasonably be obtained by the trustee, that one bid shall be used. If the trustee cannot reasonably obtain at least one bid for $10,000,000 original principal amount of the debentures from a nationally

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      In connection with any conversion upon satisfaction of the above trading price condition, the trustee shall have no obligation to determine the trading price of the debentures unless we have requested such determination; and we will have no obligation to make such request unless you provide us with reasonable evidence that the trading price per debenture would be less than 98% of the product of the closing sale price of our common stock and the number of shares of common stock issuable upon conversion of such debenture. At such time, we will instruct the trustee to determine the trading price of the debentures beginning on the next trading day and on each successive trading day until the trading price per such debenture is greater than or equal to 98% of the product of the closing sale price of our common stock and the number of shares issuable upon conversion of such debenture.

      Conversion Rights Upon Notice of Redemption. A holder may surrender debentures called for redemption for conversion into shares of our common stock at any time prior to the close of business on the business day immediately preceding the redemption date, even if the debentures are not otherwise convertible at such time. A debenture for which a holder has delivered a purchase notice or a change in control purchase notice, as described below, requiring us to purchase the debenture may be surrendered for conversion only if such notice is withdrawn in accordance with the indenture.

      Conversion Rights Upon Occurrence of Certain Corporate Transactions. If we are party to a consolidation, merger or binding share exchange pursuant to which shares of our common stock would be converted into cash, securities or other property, a holder may surrender debentures for conversion into shares of our common stock at any time from and after the date that is 15 days prior to the anticipated effective date of the transaction until 15 days after the actual date of such transaction and, at the effective time, the right to convert a debenture into shares of our common stock will be changed into a right to convert such debenture into the kind and amount of cash, securities or other property of SLM Corporation or another person that the holder would have received if the holder had converted the holder’s debenture immediately prior to the transaction. If such transaction also constitutes a change in control, the holder will be able to require us to purchase all or a portion of such holder’s debentures as described under “— Change in Control Permits Purchase of Debentures by Us at the Option of the Holder.”

      If we elect to:

we must notify you at least 20 days prior to the ex-dividend date for such distribution. Once we have given such notice, you may surrender your debentures for conversion at any time until the earlier of the close of business on the business day immediately preceding the ex-dividend date or any announcement by us that such distribution will not take place. No adjustment to your ability to convert will be made if you will otherwise participate in the distribution without conversion.

      Upon determination that debenture holders are or will be entitled to convert their debentures into shares of our common stock in accordance with the foregoing provisions, we will issue a press release and publish such information on our website on the World Wide Web.

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Conversion Procedures

      To convert your debenture into common stock you must do the following (or comply with DTC procedures for doing so in respect of your beneficial interest in debentures evidenced by a global debenture):

      Pursuant to the indenture, the date on which all of the foregoing requirements have been satisfied is the conversion date.

      Upon conversion of debentures, a holder will not receive any cash payment of interest (unless such conversion occurs between a regular record date and the interest payment date to which it relates). Our delivery to the holder of the full number of shares of our common stock into which the debenture is convertible, together with any cash payment for such holder’s fractional shares, or cash or a combination of cash and shares of our common stock in lieu thereof, will be deemed:

      As a result, increases in the accreted principal amount and unpaid interest, including contingent interest, if any, through the conversion date are deemed to be paid in full rather than cancelled, extinguished or forfeited.

      Notwithstanding the above, if debentures are converted after a record date but prior to the next succeeding interest payment date, holders of such debentures at the close of business on the record date will receive the interest payable on such debentures on the corresponding interest payment date notwithstanding the conversion. Such debentures, upon surrender for conversion, must be accompanied by funds equal to the amount of interest payable on the debentures so converted; provided that no such payment need be made if (1) we have specified a redemption date that is after a record date and prior to the date three business days after the next interest payment date, (2) we have specified a purchase date following a change in control that is during such period or (3) only to the extent of overdue interest, any overdue interest, or overdue contingent interest, if any, exists at the time of conversion with respect to such debenture.

      In lieu of delivery of shares of our common stock upon conversion of any debentures, for all or any portion of the debentures, we may elect to pay holders surrendering debentures an amount in cash per debenture (or a portion of a debenture) equal to the average of the closing sale price of our common stock for the five trading day period starting the third trading day following the conversion date of the debentures multiplied by the conversion rate in effect on the conversion date. We will inform the holders through the trustee no later than two business days following the conversion date of our election to deliver shares of our common stock or to pay cash in lieu of delivery of the shares, unless we have already informed holders of our election in connection with our optional redemption of the debentures as described under “— Redemption of Debentures at Our Option.” Shares of our common stock and cash deliverable upon conversion will be delivered through the conversion agent no later than the third business day following the determination of the average stock price referred to above. If we elect to pay all of such payment in cash, the payment will be made to holders surrendering debentures no later than the tenth business day following the applicable conversion date. If an event of default, as described under “— Events of Default; Waiver and Notice” below (other than a default in a cash payment upon conversion of the debentures), has occurred and is continuing, we may not pay cash upon conversion of any debentures or portion of the debentures (other than cash for fractional shares).

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      For a discussion of the tax treatment for a holder converting debentures, see “Material U.S. Federal Income Tax Considerations — Tax Consequences to U.S. Holders — Sale, Exchange, Conversion or Retirement of the Debentures.”

      Conversion Rate Adjustments. The conversion rate will be adjusted for:

      In the event that we make a distribution to all holders of our common stock consisting of capital stock of, or similar equity interests in, a subsidiary or other business unit of ours, the conversion rate will be adjusted based on the market value of the securities so distributed relative to the market value of our common stock, in each case based on the average closing sale prices of those securities for the 10 trading days commencing on and including the fifth trading day after the date on which “ex-dividend trading” commences for such dividend or distribution on the New York Stock Exchange or such other national or regional exchange or market on which the securities are then listed or quoted.

      If an adjustment is required to be made under this clause as a result of a distribution that is a quarterly dividend, the adjustment would be based upon the amount by which the distribution exceeds the amount of the quarterly cash dividend permitted to be excluded pursuant to this clause. If an adjustment is required to be made under this clause as a result of a distribution that is not a quarterly dividend, the adjustment would be based upon the full amount of the distribution.

      To the extent that we adopt a rights plan during the term of the debentures, you will receive, upon conversion of your debentures, in addition to the common stock, the rights under the rights plan unless, prior

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      In the event of:

in which holders of our common stock would be entitled to receive stock, other securities, other property, assets or cash for their common stock, upon conversion of your debentures you will be entitled to receive the same type of consideration which you would have been entitled to receive if you had converted the debentures into our common stock immediately prior to any of these events.

      You may in certain situations be deemed to have received a distribution subject to U.S. federal income tax as a dividend in the event of any taxable distribution to holders of common stock or in certain other situations requiring a conversion rate adjustment. See “Material U.S. Federal Income Tax Considerations.”

      We may, from time to time, increase the conversion rate for a period of at least 20 days if our board of directors has made a determination that this increase would be in our best interests. Any such determination by our board will be conclusive. We would give holders at least 15 days’ notice of any increase in the conversion rate. In addition, we may increase the conversion rate if our board of directors deems it advisable to avoid or diminish any income tax to holders of common stock resulting from any stock or rights distribution. See “Material U.S. Federal Income Tax Considerations.”

      We will not be required to make an adjustment in the conversion rate unless the adjustment would require a change of at least 1% in the conversion rate. However, we will carry forward any adjustments that are less than 1% of the conversion rate. Except as described above in this section, we will not adjust the conversion rate for any issuance of our common stock or convertible or exchangeable securities or rights to purchase our common stock or convertible or exchangeable securities.

Contingent Interest

      We will pay contingent interest to holders of the debentures during any three-month period from and including an interest payment date to but excluding the next interest payment date, commencing with the three-month period beginning July 25, 2007, only if (a) the average trading price of the debentures for a five trading day measurement period immediately preceding the first day of the applicable three-month period equals 130% or more of the accreted principal amount of the debentures, (b) the debentures are immediately convertible on the first day of such measurement period and (c) the debentures are then redeemable at our option. For example, if the debentures are successfully remarketed on any remarketing reset event date, they will not be redeemable at our option for the next four years and no contingent interest will be payable during that time. The amount of contingent interest payable in any interest period will be equal to the conversion rate in effect as of the first day of such interest period multiplied by the payment factor for such interest period. The payment factor for each interest period is set forth in the table below, subject to adjustment for any subdivisions, combinations or certain reclassifications of shares of our common stock.

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      If (a) the average trading price of the debentures for a five trading day measurement period immediately preceding the first day of the applicable three-month period equals 200% or more of the accreted principal amount of the debentures, (b) the debentures are immediately convertible on the first day of such measurement period, and (c) the debentures are redeemable at our option, we will pay an additional amount

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      Contingent interest, if any, will accrue from the first day of any interest period and be payable on the interest payment date at the end of the relevant three-month period to holders of the debentures as of the record date relating to such interest payment dates.

      Upon determination that debenture holders will be entitled to receive contingent interest during a relevant three-month period, we will issue a press release and publish such information on our website on the World Wide Web as soon as practicable.

Remarketing Reset Event

      A remarketing reset event will occur if the applicable stock price, which is the average of the closing sale prices of our common stock over the five trading day period ending on the trading day immediately preceding each remarketing reset event date, is less than the conversion price. Remarketing reset event dates occur on July 25 of 2007, 2011, 2015, 2019, 2023, 2027 and 2031.

      Appointment of Remarketing Agent and Notice to Holders. We will appoint a remarketing agent and enter into a remarketing agreement at least 30 calendar days prior to each remarketing reset event date. Each remarketing agreement will provide that the obligations of the parties are conditioned upon the occurrence of a remarketing reset event. The remarketing agent will be a nationally recognized investment banking firm and will not be one of our affiliates. At this time, our only responsibility with respect to any remarketing reset event is the appointment of the remarketing agent and compliance with the provisions of the indenture.

      We will request, not later than 20 business days prior to the date by which holders must elect to tender debentures in any remarketing, that the depositary notify its participants holding debentures of (i) the potential remarketing, (ii) the procedures a holder must follow to elect to participate in the remarketing and (iii) the date by which such election must be made. Such notice also will set forth the holders’ right to require us to purchase their debentures if such remarketing is not successful as described below. We will issue a press release and publish such information on our website on the World Wide Web.

      Holder Notice to Participate in Remarketing. Each holder of debentures will have the right to elect to participate in a remarketing on any remarketing reset event date. In order to elect to participate in the first remarketing, holders must notify the paying agent on or before the business day prior to the remarketing reset event date of the number of debentures they wish to have remarketed if a remarketing reset event occurs on the remarketing reset event date. Holders must notify the paying agent three business days prior to the applicable remarketing reset event date for any subsequent remarketing.

      Redemption. If we give notice of redemption of debentures prior to a remarketing reset event date, then no remarketing of those debentures will occur, and the terms of the debentures will not be reset. Holders who elected to have debentures remarketed will have the right, which will be deemed to be exercised, to require us to purchase such debentures at 100% of their accreted principal amount, plus accrued and unpaid interest, if any, to, but excluding, the date of purchase.

      Successful Remarketing. Upon a remarketing reset event and effective the related remarketing reset event date, (i) the yield on the debentures will be reset to 3-month LIBOR adjusted by a spread that permits all the debentures tendered for remarketing to be purchased by investors at a price, net of any remarketing fee, equal to 100% of their accreted principal amount; provided that the yield will not be reset to less than 0% per annum; (ii) the conversion rate on the debentures will be reset to equal the accreted principal amount of the debentures on that date divided by 175% of the applicable stock price, provided that in no event will the conversion rate exceed 26.5251 shares of our common stock per debenture, subject to adjustment; (iii) the principal amount of the debentures will accrete daily at the reset yield until the next remarketing reset event date and (iv) a holder of debentures will not have the right to require us to repurchase the debentures except in limited circumstances. The remarketing agent will communicate to the trustee, paying agent and depositing the applicable spread and new conversion rate by approximately 4:30 p.m. New York City time on the remarketing reset event date.

      The remarketing agent will deduct its fee from the proceeds of any remarketing and remit the remaining proceeds, which will be at least 100% of the accreted principal amount of the debentures remarketed, to the

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      We have covenanted in our indenture to use our reasonable best efforts to effect the remarketing of the debentures as described in this prospectus. If in the judgment of our counsel or counsel to the remarketing agent, a current prospectus or a separate registration statement is required to effect the remarketing of the debentures, we will (i) deliver a current prospectus; (ii) use our reasonable best efforts to ensure that a registration statement covering the full accreted principal amount of debentures to be remarketed on any remarketing reset event date will be effective in a form that will enable the remarketing agent to rely on it in connection with the remarketing process or (iii) effect such remarketing pursuant to Rule 144A under the Securities Act or any other applicable exemption from registration requirements. We do not intend, directly or through our affiliates, to place bids in any remarketing. However, in the event that we and/or one of our affiliates submits a bid for the debentures in a remarketing, we will ensure that a registration statement has been filed and has been declared effective for that remarketing.

      Failed Remarketing. If a remarketing of the debentures is required on any remarketing reset event date but the remarketing is not successful, each holder of debentures will have the right to require us on such remarketing reset event date to purchase for cash all or a portion of such holder’s debentures at 100% of the accreted principal amount, plus accrued and unpaid interest, if any, to, but excluding, the date of purchase. Each holder must notify the paying agent on or prior to the business day immediately preceding the related remarketing reset event date of the number of debentures it wants us to purchase on such remarketing reset event date in the event of a failed remarketing. Holders who have elected to remarket debentures will be deemed to exercise this purchase right with respect to all such debentures. We will deliver payment for such repurchase as promptly as possible following the applicable remarketing reset event date. The remarketing generally will not be successful if either committed purchasers cannot be obtained for all of the debentures tendered in the remarketing at the new spread, or any committed purchasers default on their purchase obligations.

      If the debentures are not successfully remarketed in a remarketing, the yield on the debentures will be reset to the rate equal to 3-month LIBOR adjusted by an applicable spread necessary, in the judgment of the remarketing agent based on bids from at least three independent nationally recognized securities dealers selected by the remarketing agent, for the debentures to trade at a price equal to 100% of their accreted principal amount. If the remarketing agent is not able to obtain bids from at least three independent nationally recognized securities dealers on a remarketing reset event date, the reset rate will be the reset rate in effect prior to such remarketing, or if no reset rate has previously been determined, the regular interest rate or yield in effect for the debentures immediately prior to the applicable remarketing reset event date.

      If holders elect to remarket less than $50,000,000 aggregate original principal amount of debentures on any remarketing reset event date, no remarketing will take place on such date and the yield of the debentures will be reset as described above. In addition, holders who elected to have debentures remarketed, but only those holders, will have the right, which will be deemed to be exercised, to require us to purchase such debentures at 100% of the accreted principal amount thereof, plus accrued and unpaid interest, if any, to, but excluding, the date of purchase.

Redemption of Debentures at Our Option

      Prior to July 25, 2007, the debentures will not be redeemable at our option. Beginning on July 25, 2007, we may redeem the debentures for cash at any time as a whole, or from time to time in part, except that if a remarketing reset event occurs and we have not given notice of redemption of the debentures prior to such remarketing reset event date, the debentures will not thereafter be redeemable at our option until on or after the next remarketing reset event date. The redemption price of a debenture will be the accreted principal amount of such debenture on the redemption date, plus accrued and unpaid interest, if any, to, but excluding, such date. We will give not less than 30 days nor more than 60 days notice of redemption by mail to holders of the debentures. The notice of redemption will inform the holders of our election to deliver shares of our common stock or to pay cash or a combination of cash and common stock in the event that a holder elects to convert debentures in connection with the redemption.

      If we decide to redeem fewer than all of the outstanding debentures, the trustee may select the debentures by lot, pro rata, or by another method the trustee considers fair and appropriate. If the trustee

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      The accreted principal amount of a debenture will be equal to the original principal amount of $1,000 per debenture increased daily by a variable yield, which until July 25, 2007 will be 0% per annum and, unless a remarketing reset event occurs, commencing on July 25, 2007 will be reset quarterly on each LIBOR reset date to a rate of 3-month LIBOR minus .05% per annum. Regardless of the level of 3-month LIBOR, however, this yield will not be less than 0% per annum. Because the redemption price of a debenture at any time is dependent upon the accreted principal amount of a debenture at that time, the redemption price cannot be determined at this time. The following table indicates what the redemption prices would be on each date below if the yield on the debentures was a constant 2.00%, 5.00% and 8.00% from July 25, 2007. This table represents an example of only three possibilities and you should realize that because LIBOR and therefore the yield on the debentures will fluctuate, any increases in accreted principal amount and redemption prices will differ, and may differ significantly, from the results below. The redemption price of a debenture redeemed between the dates below would include an additional amount reflecting the additional yield accrued and accrued contingent interest, if any, since the next preceding date in the table.