144 0001660981 XXXXXXXX LIVE 0001845257 LIFESTANCE HEALTH GROUP, INC. 001-40478 4800 N. SCOTTSDALE ROAD SUITE 2500 SCOTTSDALE AZ 85251 602-7672100 SUMMIT PARTNERS ENTREPRENEUR ADVISORS FUND II, L.P. Owner Common Stock Morgan Stanley & Co. LLC

1585 Broadway New York NY 10036

4804 25989.64 388936394 08/18/2025 NASDAQ Common Stock 06/10/2021 Pre-IPO Transactions LifeStance Health Group Inc. N 27568 06/10/2021 Equity interests in the Issuer were purchased pre-IPO. Y 08/18/2025 Adam H. Hennessey