
MERGER PROPOSED—YOUR VOTE IS VERY IMPORTANT To the Shareholders of HomeStreet, Inc.: On behalf of the board of directors of HomeStreet, Inc. (“HomeStreet”), we are pleased to enclose theaccompanying proxy statement/prospectus/consent solicitation statement relating to, among other matters, theproposed combination of Mechanics Bank, a California banking corporation (“Mechanics”), and HomeStreet. Weare requesting that you take certain actions as a holder of HomeStreet common stock. On March28, 2025, HomeStreet, HomeStreet Bank, a Washington state-chartered commercial bank and whollyowned subsidiary of HomeStreet (“HomeStreet Bank”), and Mechanics entered into an Agreement and Plan ofMerger (as may be amended, modified or supplemented from time to time in accordance with its terms, the“merger agreement”) providing for an all-stock business combination between HomeStreet and Mechanics. Onthe terms and subject to the conditions set forth in the merger agreement, HomeStreet Bank will merge with andinto Mechanics (the “merger”), with Mechanics surviving the merger and becoming a wholly owned subsidiaryofHomeStreet(HomeStreet,as the resulting holding company of Mechanics following the merger,the“combined company”). In connection with the merger, HomeStreet will be renamed “Mechanics Bancorp”.Following the consummation of the merger, HomeStreet will remain a publicly traded company. Upon the terms and subject to the conditions set forth in the merger agreement, at the effective time of the merger(the “effective time”) each share of common stock, par value $50 per share, of Mechanics designated as votingcommon stock (the “Mechanics voting common stock”) issued and outstanding immediately prior to the effectivetime, subject to certain exceptions, will be converted into the right to receive 3,301.0920 shares (the “ClassAexchange ratio”) of ClassA common stock, no par value, of the combined company (the “ClassA commonstock”). All existing shares of HomeStreet common stock currently authorized and held by HomeStreetshareholders (the “HomeStreet common stock”) will be redesignated as ClassA common stock at the effectivetime pursuant to the amended and restated articles of incorporation of the combined company (the “articlesamendment”) that will be adopted in connection with the merger. Further, upon the terms and subject to theconditions set forth in the merger agreement, at the effective time each share of common stock, par value $50 pershare, of Mechanics designated as non-voting common stock (the “Mechanics non-voting common stock”, andtogether with the Mechanics voting common stock, the “Mechanics common stock”) issued and outstandingimmediately prior to the effective time will be converted into the right to receive 330.1092 shares (the “ClassBexchange ratio”, and together with the ClassA exchange ratio, the “exchange ratios”) of ClassB common stock,no par value, of the combined company (the “ClassB common stock,” and together with the ClassA commonstock, the “combined company common stock”), which will be newly created pursuant to the articles amendment. HomeStreet common stock is traded on the Nasdaq Stock Market (“Nasdaq”) under the symbol “HMST.” Theclosing price of HomeStreet common stock on Nasdaq on March28, 2025, the last trading day before the publicannouncement of the merger, was $9.30 per share. The closing price of HomeStreet common stock on the NasdaqonJuly 14,2025,the last practicable trading day before the printing date of this proxystatement/prospectus/consent solicitation statement, was $13.43 per share. Based on a negotiated valuation of(a)$300million for HomeStreet and (b) $3.3billion for Mechanics that was agreed in connection with themerger, the implied value of the merger consideration payable for each share of existing HomeStreet commonstock on March28, 2025 was $15.53, which is based on the number of shares outstanding as of December31,2024, shares issued from December31, 2024 through January14, 2025, and unvested RSUs / PSUs as ofJanuary10, 2025. Mechanics common stock is privately held.We urge you to obtain current marketquotations for existing HomeStreet common stock. Immediately following the completion of the merger, HomeStreet shareholders will continue to own their sharesof HomeStreet common stock, which will be redesignated as ClassA common stock. We expect the merger to qualify as a “reorganization” within the meaning of Section 368(a) of the Code.Accordingly, Mechanics shareholders generally will not recognize any gain or loss for U.S. federal income taxpurposes on the exchange of shares of Mechanics common stock for combined company common stock in themerger, except with respect to any cash received by Mechanics shareholders in lieu of fractional shares ofcombined company common stock. TABLE OF CONTENTS Based on the total number of shares of Mechanics outstanding as of July1, 2025, the total number of shares ofnew HomeStreet common stock expected to be issued to Mechanics sh