LifeStance Health Group Inc 美股招股说明书（2026年2月26日版）

LifeStance Health Group, Inc. Common Stock The selling stockholders identified in this prospectus supplement are offering 25,000,000 shares of common stock, parvalue $0.01 per share (the “common stock”), of LifeStance Health Group, Inc. (the “Company”). The Company is not sellingany shares of common stock under this prospectus supplement and will not receive any proceeds from the sale of shares by theselling stockholders. Subject to the completion of this offering, we intend to purchase from the underwriter 7,000,000 shares of our commonstock that are subject to this offering at a price per share equal to the price per share paid by the underwriter to the sellingstockholders in this offering (the “Share Repurchase”). The repurchased shares of common stock will no longer be outstandingafter this offering. The underwriter will not receive any compensation for the shares of our common stock being purchased byus. The offering is not conditioned upon the completion of the Share Repurchase. We cannot assure you that this offering or theShare Repurchase will be consummated. Nothing in this prospectus supplement should be construed as an offer to sell, or thesolicitation of an offer to buy, any shares of our common stock subject to the Repurchase. The Company’s common stock is listed on the Nasdaq Global Select Market (“Nasdaq”) under the symbol “LFST.” OnFebruary24, 2026, the last sale price of the common stock as reported on Nasdaq was $7.14 per share. The underwriter has agreed to purchase shares of common stock from the selling stockholders at a price of $pershare, which will result in approximately $of proceeds to the selling stockholders before expenses. The underwriter mayoffer the shares of common stock offered by this prospectus supplement, other than shares subject to the Share Repurchase,from time to time at market prices prevailing at the time of sale, at prices related to such prevailing market prices, atnegotiated prices, at fixed prices or at prices that may be subject to change. The underwriter may effect such transactions byselling shares of common stock to or through dealers, and such dealers may receive compensation in the form of discounts,concessions or commissions from the underwriter and/or purchasers of shares of common stock for whom they may act asagents or to whom they may sell as principal. See “Underwriting” for additional information regarding underwritingcompensation. Investing in the Company’s common stock involves risks. See “Risk Factors” beginning on pageS-4 and in the documents incorporated by reference herein. 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 is truthful or complete. Any representation tothe contrary is a criminal offense. The information in this preliminary prospectus supplement is not complete and may be changed. This preliminary prospectussupplement is not an offer to sell these securities and it is not soliciting an offer to buy these securities in any jurisdiction where the, 2026, through the book-entry offer or sale is not permitted.The underwriter expects to deliver the shares of common stock on or aboutfacilities of The Depository Trust Company. Table of Contents TABLE OF CONTENTS Prospectus Supplement ABOUT THIS PROSPECTUS SUPPLEMENTWHERE YOU CAN FIND MORE INFORMATION; INCORPORATION OF CERTAIN DOCUMENTS BY REFERENCECAUTIONARY NOTE REGARDING FORWARD-LOOKING STATEMENTSPROSPECTUS SUPPLEMENT SUMMARYTHE OFFERINGRISK FACTORSUSE OF PROCEEDSSELLING STOCKHOLDERSMATERIAL U.S. FEDERAL INCOME TAX CONSIDERATIONS TO NON-U.S. HOLDERSUNDERWRITINGLEGAL MATTERSEXPERTS ProspectusABOUT THIS PROSPECTUSWHERE YOU CAN FIND MORE INFORMATION; INCORPORATION OF CERTAIN DOCUMENTS BY REFERENCECAUTIONARY NOTE REGARDING FORWARD-LOOKING STATEMENTS THE COMPANYRISK FACTORSUSE OF PROCEEDSSELLING STOCKHOLDERSDESCRIPTION OF CAPITAL STOCKPLAN OF DISTRIBUTIONLEGAL MATTERS EXPERTS Table of Contents ABOUT THIS PROSPECTUS SUPPLEMENT This document consists of two parts. The first part is this prospectus supplement, which describes the specific terms of this offering andsupplements information contained in the accompanying prospectus and the documents incorporated by reference in this prospectus supplement and theaccompanying prospectus. The second part is the accompanying prospectus, which describes more general information, some of which may not apply tothis offering. You should read both this prospectus supplement and the accompanying prospectus, including the documents incorporated by referenceherein and therein. If information in this prospectus supplement is inconsistent with the accompanying prospectus, this prospectus supplement willsupersede the information in the accompanying prospectus. Any statement made in this prospectus supplement, the accompanying prospectus or in a document incorporated or deemed to be incorporated byreference