LifeStance Health Group, Inc.

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

SCHEDULE 14A

Proxy Statement Pursuant to Section 14(a) of the

Securities Exchange Act of 1934

(Amendment No. )

Filed by the Registrant☒

Filed by a Party other than the Registrant☐

Check the appropriate box:

(Name of Registrant as Specified In Its Charter)

(Name of Person(s) Filing Proxy Statement, if other than the Registrant)

Payment of Filing Fee (Check all boxes that apply):

4800 N. Scottsdale Road

Suite 2500

Scottsdale, Arizona 85251

Dear Stockholders:

You are cordially invited to attend the LifeStance Health Group, Inc. Annual Meeting of Stockholders (the “Annual Meeting”) on Tuesday, June 3, 2025, at 1:00 p.m. Pacific Time. Our Annual Meeting will be in a fully virtual format. We believe hosting a virtual meeting will allow for greater stockholder attendance at the Annual Meeting by enabling stockholders who might not otherwise be able to travel to a physical meeting to attend online and participate from any location. Stockholders will be able to register to attend and vote online (for those who intend to vote at the Annual Meeting) atwww.proxydocs.com/LFST. Upon completing your registration, you will receive further instructions via email, including a unique link that will allow you to access, and to vote and submit questions during, the Annual Meeting. The Company has designed the format of the Annual Meeting to ensure that stockholders are afforded the same rights and opportunities to participate as they would at an in-person meeting, using online tools to ensure stockholder access and participation.

On April 23, 2025, we mailed to our stockholders a Notice of Internet Availability of Proxy Materials (the “Notice”) containing instructions on how to access our proxy statement for the Annual Meeting and our 2024 Annual Report on Form 10-K. The Notice also provides instructions on how to vote online or by telephone and includes instructions on how to receive a paper copy of the proxy materials by mail. The matters to be acted upon at the meeting are described in the attached Notice of Annual Meeting and Proxy Statement.

The proxy statement accompanying this letter describes the business we will consider at the meeting. Your vote is important regardless of the number of shares you own. Whether or not you plan to attend the Annual Meeting, we urge you to vote your shares promptly by mail, telephone or Internet as instructed on the enclosed proxy card or voting instruction card. Proxies forwarded by or for brokers or fiduciaries should be returned as requested by them.

We hope that you will be able to join us virtually on June 3 rd.

Sincerely,

David Bourdon

Chief Executive Officer

IF YOU PLAN TO ATTEND THE MEETING

The Notice of Internet Availability, proxy card, or voting instruction form that accompanied your proxy materials includes your control number, which when entered atwww.proxydocs.com/LFST will serve as an admission ticket for one stockholder to register for and attend the Annual Meeting. On April 23, 2025, we also first mailed this Proxy Statement and the enclosed proxy card to certain stockholders. If you received a paper copy of the proxy materials in the mail, the proxy card includes the control number for one stockholder to attend the Annual Meeting. Stockholders holding stock in brokerage accounts (“street name” holders) will need to obtain the control number reflecting their stock ownership as of the record date, April 11, 2025 from their broker, bank or other nominee.

4800 N. Scottsdale Road

Suite 2500

Scottsdale, Arizona 85251

NOTICE OF ANNUAL MEETING OF STOCKHOLDERS

Dear Stockholder:

The 2025 Annual Meeting of Stockholders (the “Annual Meeting”) of LifeStance Health Group, Inc. (the “Company”) will be held on Tuesday, June 3, 2025. Our Annual Meeting will be in a fully virtual format. We believe hosting a virtual meeting will allow for greater stockholder attendance at the Annual Meeting by enabling stockholders who might not otherwise be able to travel to a physical meeting to attend online and participate from any location. The Annual Meeting may be accessed by entering the control number provided on your proxy card, voting instruction form, or Notice of Internet Availability atwww.proxydocs.com/LFST. Login will be available starting at 12:45 p.m. Pacific Time and the meeting will begin promptly at 1:00 p.m. Pacific Time, for the following purposes:

Election of the three director nominees named in the Proxy Statement to serve until the 2028 annual meeting of stockholders;

Ratification of the appointment of PricewaterhouseCoopers LLP ("PwC") as our independent registered public accounting firm for the year ended December 31, 2025;

Approval, on an advisory basis, of the compensation of the Company's named executive officers; and

Transacting such other business as may properly come before the meeting or any adjournment thereof.

These proposals are more fully described in the Proxy Statement accompanying this Notice.

April 11, 2025 has been fixed as the record date for the determination of the stockholders entitled to notice of and to vote at the Annual Meeting or any adjournments thereof. Only stockholders of record at the close of business as of the record date will be entitled to notice of, and to vote at, the Annual Meeting. If you would like an opportunity to view the stockholder list, it will be available 10 days in advance of the meeting. Please contact the Corporate Secretary to make accommodations to view the list. Your vote is important. Whether or not you expect to attend the Annual Meeting, we encourage you to vote by Internet, by telephone or by completing, signing and dating your printable proxy card and returning it as soon as possible. If you are voting by Internet or by telephone, please follow the instructions on your proxy card. If you attend the Annual Meeting and vote during the meeting, your proxy will not be used.

If you need assistance voting your shares, please send an e-mail to investor.relations@lifestance.com.

You may attend the Annual Meeting and vote your shares during the meeting, even if you previously voted by Internet, telephone or if you returned your proxy card. Your proxy (including a proxy granted by the Internet or by telephone) may be revoked by sending in another signed proxy card with a later date, sending a letter revoking your proxy to the Company’s Corporate Secretary in Scottsdale, Arizona, voting again by Internet or telephone, or attending the Annual Meeting and voting during the meeting. If you are a registered stockholder (meaning you hold your shares directly in your name), you must enter a valid control number to attend the meeting. If you are a beneficial stockholder (meaning your shares are held in the name of a broker, bank, nominee or other holder of record), you will also need to enter a valid control number showing proof of ownership to attend the meeting.

We look forward to seeing you. Thank you for your ongoing support of and interest in LifeStance Health Group, Inc.

By Order of the Board of Directors,

Ryan Pardo

Chief Legal Officer and Corporate Secretary

April 23, 2025

Important notice regarding the Internet availability of proxy materials for the stockholders meeting to be held on June 3, 2025. Stockholders may access, view and download the 2025 Proxy Statement and the 2024 Annual Report atwww.proxydocs.com/LFST.

TABLE OF CONTENTS

PROXY STATEMENT

FOR ANNUAL MEETING OF STOCKHOLDERS

June 3, 2025