$500,000,000 6.495% Fixed-to-Floating Rate Senior Notes due 2032 SLM CORPORATION We are offering $500,000,000 aggregate principal amount of 6.495% Fixed-to-Floating Rate Senior Notes due 2032 (the “notes”). During the period from, and including, the issue date, to, but excluding May15, 2031, the notes will bear interest at a rate of 6.495% per annum.Such interest on the notes will be payable semi-annually in arrears on May15 and November15 of each year, beginning on November15, 2026, andending on May15, 2031. Beginning on May15, 2031, the notes will bear interest at a floating rate per annum equal to Compounded SOFR (as definedherein) plus 271 basis points, payable quarterly in arrears on August15, 2031, November15, 2031, February15, 2032, and at the maturity date of thenotes. The notes will mature on May15, 2032. We may redeem the notes at the applicable times and at the applicable redemption price described under “Description of the Notes—OptionalRedemption.” The notes will be our senior obligations and will rank without preference or priority among themselves and equally in right of payment with all ofour existing and future unsecured and unsubordinated obligations. The notes are not savings accounts, deposits or other obligations of any of our bank ornon-bank subsidiaries and are not insured or guaranteed by the Federal Deposit Insurance Corporation (the “FDIC”) or any other governmental agency.The notes are effectively subordinated to our secured obligations to the extent of the value of the collateral securing such obligations and are structurallysubordinated to all indebtedness and other liabilities of our subsidiaries, including our bank subsidiary. The notes will not be listed on any securities exchange. Currently, there is no established trading market for the notes. Investing in the notes involves risks. See “Risk Factors” beginning on page S-13. None of the Securities and Exchange Commission (the “SEC”), the FDIC or any state securities commission has approved or disapprovedof these securities or passed upon the adequacy or accuracy of this prospectus supplement or the accompanying prospectus. Any representationto the contrary is a criminal offense. This prospectus supplement and the accompanying prospectus are not intended to constitute an offer to, and the notes should not be purchased,held or otherwise acquired by, a “specified foreign entity” as defined in Section7701(a)(51)(B) of the Internal Revenue Code of 1986, as amended (a“specified foreign entity”). Each purchaser of the notes, by accepting such notes, will be deemed to have represented, warranted and agreed that it is nota “specified foreign entity.” The underwriters expect to deliver the notes to purchasers in book-entry form only through The Depository Trust Company, for the benefit of itsparticipants, including Clearstream Banking, S.A. and Euroclear Bank S.A./N.V., on or about May15, 2026. J.P.Morgan Barclays Co-Managers GoldmanSachs&Co.LLCRBCCapitalMarkets BofASecuritiesMorganStanley TABLE OF CONTENTS Prospectus Supplement About This Prospectus SupplementCautionary Note Regarding Forward-Looking StatementsSummarySummary Historical Financial InformationRisk FactorsUse of ProceedsCapitalizationDescription of the NotesMaterial U.S. Federal Income Tax ConsequencesCertain ERISA ConsiderationsUnderwritingLegal MattersExpertsIncorporation by Reference Prospectus About This ProspectusForward-Looking StatementsWhere You Can Find More InformationIncorporation of Certain Information by ReferenceSLM CorporationRisk FactorsUse of ProceedsSecurities We May OfferAdditional InformationDescription of Capital Stock Description of Debt Securities ABOUT THIS PROSPECTUS SUPPLEMENT This document is in two parts. The first part is this prospectus supplement, which contains the terms of this offering of notes. The second part, theaccompanying prospectus dated July31, 2024, which is part of our Registration Statement on Form S-3, gives more general information, some of whichmay not apply to this offering. This prospectus supplement and the information incorporated by reference in this prospectus supplement may add to, update or changeinformation contained in the accompanying prospectus. If there is any inconsistency between the information in this prospectus supplement, on the onehand, and the information contained in the accompanying prospectus or any document incorporated herein or therein by reference, on the other hand, theinformation in this prospectus supplement will apply and will supersede the information in the accompanying prospectus. It is important for you to read and consider all information contained or incorporated by reference in this prospectus supplement, theaccompanying prospectus and any free writing prospectus relating to this offering in making your investment decision. You should also read andconsider the information in the documents to which we have referred you in “Where You Can Find More Information” in