144 0001634415 XXXXXXXX LIVE 0001845257 LIFESTANCE HEALTH GROUP, INC. 001-40478 4800 N. SCOTTSDALE ROAD SUITE 2500 SCOTTSDALE AZ 85251 6027672100 Summit Partners Growth Equity Fund IX-A, L.P. Owner Common Stock Citadel Securities LLC

830 Brickell Plaza, Floor 15 Miami FL 33131

1742770 18508217.40 382055609 08/10/2026 NASDAQ Common Stock 06/10/2021 Pre-IPO Transactions LifeStance Health Group Inc. N 29542786 06/10/2021 Equity interests in the Issuer were purchased pre-IPO. Y 08/10/2026 Adam H. Hennessey