WEC能源美股招股说明书(2026-02-24版)

4.75% Senior Notes due January15, 2028 WEC Energy Group,Inc. is offering $400,000,000 aggregate principal amount of its 4.75% Senior Notes due January15,2028 (the “new Notes”). The new Notes offered hereby are part of the same series of debt securities as our $450,000,000 aggregateprincipal amount 4.75% Senior Notes due January15, 2028 issued on January11, 2023 (the “initial Notes” and, together with the newNotes, the “Notes”). Upon the issuance of the new Notes offered hereby, the aggregate principal amount of outstanding Notes will be$850,000,000. We will pay interest on the Notes semi-annually in arrears on January15 and July15 of each year, beginning onJuly15, 2026. Interest on the new Notes offered hereby will accrue from January15, 2026. The Notes will be issued only indenominations of $1,000 and integral multiples of $1,000. We may, at our option, redeem some or all of the Notes at any time prior to maturity at the applicable redemption pricesdiscussed under the caption “Certain Terms of the Notes — Redemption at Our Option.” The Notes are unsecured and rank equally with all of our other unsecured and unsubordinated debt and other obligations fromtime to time outstanding. We do not intend to apply for listing of the Notes on any securities exchange or automated quotation system. Neither the Securities and Exchange Commission (the “SEC”) nor any state securities commission has approved ordisapproved of these securities or determined if this prospectus supplement or the accompanying prospectus is truthful orcomplete. Any representation to the contrary is a criminal offense. (1)Plus accrued interest from January15, 2026.(2)The public offering price set forth above for the new Notes offered hereby does not include accrued interest of $2,163,888.89 inthe aggregate from January15, 2026 up to, but not including, the expected date of delivery of the new Notes offered hereby,which will be paid by the purchasers of the new Notes offered hereby. On July15, 2026, WEC Energy Group,Inc. will pay thispre-issuance accrued interest to the holders of the new Notes offered hereby. The underwriters expect to deliver the new Notes in book-entry form only through The Depository TrustCompany on orabout February26, 2026. This prospectus supplement and the accompanying prospectus are not intended to constitute an offer to, and the newNotes 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 (an “SFE”). By purchasing new Notes, any investor in the new Notes(including all affiliated entities that participate in such purchase) will be deemed to represent and warrant to us that it is not,and will not be, for its taxable year that includes the date of the original issuance of the new Notes, an SFE. BofA Securities Comerica Securities February23, 2026 You should rely only on the information contained or incorporated by reference in this prospectus supplement, theaccompanying prospectus and any written communication from us or the underwriters specifying the final terms of theoffering. We have not, and the underwriters have not, authorized anyone to provide you with different information. Neither wenor the underwriters are making an offer of these securities in any jurisdiction where the offer is not permitted. You shouldassume that the information contained in this prospectus supplement, the accompanying prospectus or the documentsincorporated by reference is accurate only as of their respective dates. Our business, financial condition, results of operationsand prospects may have changed since those dates. TABLE OF CONTENTS Page Prospectus Supplement SummaryS-1Risk FactorsS-4Forward-Looking Statements and Cautionary FactorsS-4Use of ProceedsS-4CapitalizationS-5Certain Terms of the NotesS-6Material United States Federal Income Tax ConsiderationsS-11Underwriting (Conflicts of Interest)S-16Legal MattersS-18ExpertsS-18Documents Incorporated by ReferenceS-18 Prospectus About this Prospectus1Risk Factors1Forward-Looking Statements and Cautionary Factors1WEC Energy Group,Inc.2Use of Proceeds3Description of Capital Stock3Description of Debt Securities6Description of Depositary Shares13Description of Purchase Contracts13Description of Units13Plan of Distribution14Legal Matters15Experts15Where You Can Find More Information15 SUMMARY In this prospectus supplement, unless the context requires otherwise, “WEC Energy Group,” “we,” “us” and “our” referto WEC Energy Group,Inc., a Wisconsin corporation, and not to the underwriters. The information below is only a summary of more detailed information included elsewhere or incorporated by referencein this prospectus supplement and the accompanying prospectus. This summary may not contain all of the information that isimportant to you or that you should consider before buying securities in this offering. Please read this entire prospectussupplement and the accompan