美国家庭人寿保险美股招股说明书(2026-05-18版)

This is an offering by Aflac Incorporated of ¥principal amount of its% Senior Notes due(the“notes”), ¥principal amount of its% Senior Notes due(the “notes”) and ¥principal amount of its% Senior Notes due(the “notes” and, together with thenotes andthenotes, the “notes”). We will pay interest on the notes semi-annually in arrears on eachand, beginning on andthe We may redeem some or all of any series of notes after the applicable par call date for such series at par plusaccrued interest to the redemption date as described under the caption “Description of the Notes — OptionalRedemption” in this prospectus supplement, and we may redeem the notes if certain events occur involving UnitedStates taxation as described under the caption “Description of the Notes — Tax Redemption” in this prospectus The notes will be our general unsecured obligations and will rank equally in right of payment with any of ourexisting and future unsecured senior indebtedness. The notes will be issued only in denominations of ¥100,000,000 andintegral multiples of ¥10,000,000 in excess thereof The notes will not be listed on any securities exchange. Currently, there is no public market for the notes.See “Risk Factors” beginning on pageS-4of this prospectus supplement, page 4 of the accompanying prospectus and“Item1A. Risk Factors” beginning on page 13 of our Annual Report on Form 10-K for the year ended December31, 2025 toread about factors you should consider before investing in the notes. Neither the Securities and Exchange Commission (the “SEC”) nor any state securities commission or any otherregulatory body has approved or disapproved of these securities or passed upon the accuracy or adequacy of this prospectussupplement or the accompanying prospectus. Any representation to the contrary is a criminal offense. Joint Book-Running Managers MizuhoThe information in this preliminary prospectus supplement is not complete and may be changed. This preliminary prospectus supplement and the accompanying prospectus are not an offerto sell these securities and they are not soliciting an offer to buy these securities in any jurisdiction where such offer or sale is not permitted. Morgan Stanley MUFG Prospectus Supplement, dated TABLE OF CONTENTS No dealer, salesperson or other person is authorized to give any information or to represent anythingnot contained in this prospectus supplement, the accompanying prospectus and any related free writingprospectus prepared by us. Neither we nor any of the underwriters take responsibility for or provideassurance as to the reliability of, any other information that others may give you. This prospectussupplement and the accompanying prospectus are an offer to sell only the notes offered hereby, but onlyunder circumstances and in jurisdictions where it is lawful to do so. The information contained or UK MIFIR PRODUCT GOVERNANCE / PROFESSIONAL INVESTORS AND ECPs ONLY TARGET Solely for the purposes of the manufacturers’ product approval process, the target market assessment inrespect of the notes has led to the conclusion that: (i)the target market for the notes is only eligiblecounterparties, as defined in the FCA Handbook Conduct of Business Sourcebook (“COBS”), andprofessional clients, as defined in Regulation (EU) No 600/2014 as it forms part of domestic law by virtueof the European Union (Withdrawal) Act 2018, as amended (respectively, “UK MiFIR” and the “EUWA”);and (ii)all channels for distribution of the notes to eligible counterparties and professional clients areappropriate. Any person subsequently offering, selling or recommending the notes (a “distributor”) should NOTICE TO PROSPECTIVE INVESTORS IN THE EUROPEAN ECONOMIC AREA None of this prospectus supplement, the accompanying prospectus or any related free writingprospectus is a prospectus for the purposes of Regulation (EU) 2017/1129, as amended (the “ProspectusRegulation”). This prospectus supplement, the accompanying prospectus and any related free writingprospectus have been prepared on the basis that any offer of notes in any Member State of the EuropeanEconomic Area (the “EEA”) (“Relevant State”) will only be made to a legal entity which is a qualifiedinvestor under the Prospectus Regulation (“Qualified Investors”). Accordingly any person making or PROHIBITION OF SALES TO EEA RETAIL INVESTORS The notes are not intended to be offered, sold or otherwise made available to and should not be offered,sold or otherwise made available to any retail investor in the EEA. For these purposes, a retail investormeans a person who is one (or more) of: (i)a retail client as defined in point (11) of Article4(1) ofDirective 2014/65/EU (as amended, “MiFID II”); or (ii)a customer within the meaning of Directive(EU)2016/97 (as amended, the “Insurance Distribution Directive”), where that customer would not qualifyas a professional client as defined in point (10) of Article4(1) of MiFID II; or (iii)not a qualified investoras defined in the Prospectu