ISSUER FREE WRITING PROSPECTUS

(RELATING TO THE PRELIMINARY PROSPECTUS

SUPPLEMENT DATED MAY 18, 2026 AND

THE PROSPECTUS DATED SEPTEMBER 6, 2024)

FILED PURSUANT TO RULE 433

REGISTRATION NO. 333-281977

MAY 21, 2026

AFLAC INCORPORATED

¥3,100,000,000 2.117% SENIOR NOTES DUE 2029

¥41,800,000,000 2.802% SENIOR NOTES DUE 2031

¥13,100,000,000 3.123% SENIOR NOTES DUE 2033

¥7,900,000,000 3.482% SENIOR NOTES DUE 2036

FINAL TERM SHEET

Dated May 21, 2026

*Note: A securities rating is not a recommendation to buy, sell or hold securities and may be subject to revision or withdrawal at any time.

**We expect that delivery of the notes will be made to investors on or about May 28, 2026, which is the fifth Tokyo business day following the date of this final term sheet (such settlement being referred to as "T+5"). Under the E.U. Central Securities Depositories Regulation, trades in the secondary market are required to settle in two London business days, unless the parties to any such trade expressly agree otherwise. Also, under Rule 15c6-1 under the Securities Exchange Act of 1934, as amended, trades in the secondary market are required to settle in one New York business day, unless the parties to any such trade expressly agree otherwise. Accordingly, purchasers who wish to trade notes earlier than the second London business day, or the New York business day, before May 28, 2026 will be required, by virtue of the fact that the notes initially will settle T+5, to specify an alternative settlement cycle at the time of any such trade to prevent failed settlement, and so should consult their own advisors.

The issuer has filed a registration statement (including a prospectus and related prospectus supplement) with the U.S. Securities and Exchange Commission (SEC) for this offering. Before you invest, you should read the prospectus supplement and prospectus for this offering in that registration statement, and other documents the issuer has filed with the SEC for more complete information about the issuer and this offering. You may get these documents for free by EDGAR at the SEC website at www.sec.gov. Alternatively, you may obtain a copy of the prospectus by calling Mizuho Securities USA LLC toll-free at 1-866-271-7403, SMBC Nikko Securities America, Inc. toll-free at 1-888-868-6856 or by email at [email protected], Morgan Stanley & Co. International plc toll-free at 1-866-718-1649 and MUFG Securities EMEA plc toll-free at 1-877-649-6848.

UK MiFIR Product Governance Rules professionals/ECPs-only / No PRIIPs KID - Manufacturer target market (UK MiFIR Product Governance Rules) is eligible counterparties and professional clients only (all distribution channels). No EEA or UK PRIIPs key information document (KID) has been prepared as not available to retail investors in EEA or the United Kingdom.

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