Mayville Engineering Co Inc美股招股说明书(2026-05-20版)

Mayville Engineering Company, Inc. 4,348,000 Shares Common Stock We are offering 4,348,000 shares of our common stock, no par value per share, as described inthis prospectus supplement and the accompanying prospectus to institutional investors. Our common stock is listed on The New York Stock Exchange under the symbol “MEC.” The lastreported sale price of our common stock on The New York Stock Exchange on May 18, 2026 was $24.92per share. Investing in our common stock involves a high degree of risk. Please read the “RiskFactors” beginning on page S-4 of this prospectus supplement, as well as in the accompanyingprospectus and the documents incorporated by reference herein and therein, for a discussion of thefactors you should carefully consider before deciding to purchase our common stock. Neither the Securities and Exchange Commission nor any state securities commission hasapproved or disapproved of these securities or passed upon the accuracy or adequacy of thisprospectus supplement or the accompanying prospectus. Any representation to the contrary is acriminal offense. (1)See “Underwriting” beginning on page S-11 of this prospectus supplement for information regarding compensation payable tothe underwriters. We have granted the underwriters an option for a period of 30 days to purchase up to anadditional 652,000 shares of common stock from us at the public offering price, less the underwritingdiscounts and commissions. Delivery of the shares of common stock to investors is expected to be made on or about May 21,2026, subject to customary closing conditions. Craig-Hallum William Blair Northland CapitalMarkets The date of this prospectus supplement is May 19, 2026. TABLE OF CONTENTS Prospectus SupplementABOUT THIS PROSPECTUS SUPPLEMENTS-iFORWARD-LOOKING STATEMENTSS-iiPROSPECTUS SUPPLEMENT SUMMARYS-1THE OFFERINGS-3RISK FACTORSS-4USE OF PROCEEDSS-5MATERIAL UNITED STATES FEDERAL INCOME TAX CONSEQUENCES FOR NON-U.S.HOLDERS OF COMMON STOCKS-6UNDERWRITINGS-11LEGAL MATTERSS-18EXPERTSS-18WHERE YOU CAN FIND MORE INFORMATIONS-19INCORPORATION OF CERTAIN INFORMATION BY REFERENCES-19ProspectusABOUT THIS PROSPECTUS1CAUTIONARY STATEMENT REGARDING FORWARD-LOOKING STATEMENTS1RISK FACTORS3MAYVILLE ENGINEERING COMPANY, INC.3USE OF PROCEEDS3DESCRIPTION OF CAPITAL STOCK3DESCRIPTION OF THE DEBT SECURITIES9DESCRIPTION OF WARRANTS18DESCRIPTION OF THE PURCHASE CONTRACTS AND PURCHASE UNITS19DESCRIPTION OF UNITS19WHERE YOU CAN FIND MORE INFORMATION20PLAN OF DISTRIBUTION21LEGAL MATTERS23EXPERTS23 ABOUT THIS PROSPECTUS SUPPLEMENT This document is in two parts. The first part is this prospectus supplement, which describes theterms of this offering and also adds to and updates information contained in the accompanying prospectusand the documents incorporated by reference herein or therein. The second part, the accompanyingprospectus, including the documents incorporated by reference into the accompanying prospectus,provides more general information. Generally, when we refer to this prospectus, we are referring to bothparts of this document combined. To the extent there is a conflict between the information contained in thisprospectus supplement and the information contained in the accompanying prospectus or any documentincorporated by reference herein or therein filed prior to the date of this prospectus supplement, youshould rely on the information in this prospectus supplement; provided that if any statement in one of thesedocuments is inconsistent with a statement in another document having a later date—for example, adocument incorporated by reference in this prospectus supplement or in the accompanying prospectus—the statement in the document having the later date modifies or supersedes the earlier statement. We have not, and the underwriters have not, authorized anyone to provide you with informationdifferent from, or in addition to, that contained or incorporated by reference in this prospectus supplement,the accompanying prospectus or any free writing prospectus prepared by or on behalf of us or to which wemay have referred you in connection with this offering. We and the underwriters take no responsibility for,and can provide no assurance as to the reliability of, any other information that others may give you. Theinformation in this prospectus supplement and the accompanying prospectus is accurate only as of its date,regardless of the time of delivery of this prospectus supplement and accompanying prospectus or of anysale of shares of our common stock. Our business, financial condition, results of operations and prospectsmay have changed materially since such date. This prospectus supplement does not contain all of the information that is important to you.You should also read and consider the information in the documents to which we have referred youin the sections entitled “Where You Can Find More Information” and “Incorporation of CertainInformation by Reference” in this prospectus supplement. We are offeri