SEC Form 4

FORM 4		UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934 or Section 30(h) of the Investment Company Act of 1940	OMB APPROVAL OMB Number: 3235-0287 Estimated average burden hours per response: 0.5
	Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

1. Name and Address of Reporting Person* SUMMIT PARTNERS L P (Last) (First) (Middle) 222 BERKELEY STREET 18TH FLOOR (Street) BOSTON MA 02116 (City) (State) (Zip)	2. Issuer Name and Ticker or Trading Symbol LifeStance Health Group, Inc. [ LFST ]	5. Relationship of Reporting Person(s) to Issuer (Check all applicable) Director 10% Owner Officer (give title below) X Other (specify below) Manager of GP of 10% owner
	3. Date of Earliest Transaction (Month/Day/Year) 05/24/2024
	4. If Amendment, Date of Original Filed (Month/Day/Year)	6. Individual or Joint/Group Filing (Check Applicable Line) Form filed by One Reporting Person X Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	3. Transaction Code (Instr. 8)		4. Securities Acquired (A) or Disposed Of (D) (Instr. 3, 4 and 5)			5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4)	6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
			Code	V	Amount	(A) or (D)	Price
Common Stock	05/24/2024		S		3,802,345(1)	D	$5.89	41,932,358(2)	I	See Footnotes.(3)(4)

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Transaction Date (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	4. Transaction Code (Instr. 8)		5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)		6. Date Exercisable and Expiration Date (Month/Day/Year)		7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4)		8. Price of Derivative Security (Instr. 5)	9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)	10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
				Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares

1. Name and Address of Reporting Person* SUMMIT PARTNERS L P (Last) (First) (Middle) 222 BERKELEY STREET 18TH FLOOR (Street) BOSTON MA 02116 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director 10% Owner Officer (give title below) X Other (specify below) Manager of GP of 10% owner

1. Name and Address of Reporting Person* SUMMIT MASTER COMPANY, LLC (Last) (First) (Middle) 222 BERKELEY STREET, 18TH FLOOR (Street) BOSTON MA 02116 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director 10% Owner Officer (give title below) X Other (specify below) Manager of GP of 10% owner

1. Name and Address of Reporting Person* SUMMIT PARTNERS ENTREPRENEUR ADVISORS GP II, LLC (Last) (First) (Middle) 222 BERKELEY STREET, 18TH FLOOR (Street) BOSTON MA 02116 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director 10% Owner Officer (give title below) X Other (specify below) GP of 10% owner

1. Name and Address of Reporting Person* SUMMIT PARTNERS GE IX, L.P. (Last) (First) (Middle) 222 BERKELEY STREET, 18TH FLOOR (Street) BOSTON MA 02116 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director 10% Owner Officer (give title below) X Other (specify below) GP of 10% owner

1. Name and Address of Reporting Person* SUMMIT PARTNERS GE IX, LLC (Last) (First) (Middle) 222 BERKELEY STREET, 18TH FLOOR (Street) BOSTON MA 02116 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director 10% Owner Officer (give title below) X Other (specify below) GP of 10% owner

1. Name and Address of Reporting Person* Summit Investors Management, LLC (Last) (First) (Middle) 222 BERKELEY STREET, 18TH FLOOR (Street) BOSTON MA 02116 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director 10% Owner Officer (give title below) X Other (specify below) Manager and GP of 10% Owner

Explanation of Responses:

1. Represents 2,328,399 shares sold by Summit Partners Growth Equity Fund IX-A, L.P., 1,453,820 shares sold by Summit Partners Growth Equity Fund IX-B, L.P., 16,253 shares sold by Summit Investors GE IX/VC IV, LLC, 2,173 shares sold by Summit Partners Entrepreneur Advisors Fund II, L.P., and 1,700 shares sold by Summit Investors GE IX/VC IV (UK), L.P.

2. Represents 25,677,643 shares held by Summit Partners Growth Equity Fund IX-A, L.P., 16,032,765 shares held by Summit Partners Growth Equity Fund IX-B, L.P., 179,239 shares held by Summit Investors GE IX/VC IV, LLC, 23,961 shares held by Summit Partners Entrepreneur Advisors Fund II, L.P., and 18,750 shares held by Summit Investors GE IX/VC IV (UK), L.P.

3. Summit Partners, L.P. is the managing member of Summit Partners GE IX, LLC, which is general partner of Summit Partners GE IX, LP, which is the general partner of Summit Partners Growth Equity Fund IX-A, L.P. and Summit Partners Growth Equity Fund IX-B, L.P. Summit Master Company, LLC is (i) the sole member of Summit Partners Entrepreneur Advisors GP II, LLC, which is the general partner of Summit Partners Entrepreneur Advisors Fund II, L.P. and (ii) the managing member of Summit Investors Management, LLC, which is the manager of Summit Investors GE IX/VC IV, LLC, and the general partner of Summit Investors GE IX/VC IV (UK), L.P.

4. Summit Master Company, LLC, as the sole member of Summit Partners Entrepreneur Advisors GP II, LLC and the managing member of Summit Investors Management, LLC, has delegated investment decisions, including voting and dispositive power, to Summit Partners, L.P. and its investment committee responsible for voting and investment decisions with respect to LifeStance Health Group, Inc. Summit Partners, L.P., through a three-person investment committee, currently composed of Peter Y. Chung, Mark A. deLaar and Craig D. Frances, has voting and dispositive authority over the shares held by each of these entities and therefore beneficially owns such shares. Each of the Summit Funds, Mr. Chung, Mr. deLaar and Dr. Frances disclaim beneficial ownership of the shares, except, in each case, to the extent of such person's or entity's pecuniary interest therein.

	Summit Partners, L.P., by Summit Master Company, LLC, its GP, by /s/ Adam Hennessey, Member	05/29/2024
	Summit Master Company, LLC, by /s/ Adam Hennessey, Member	05/29/2024
	Summit Partners Entrepreneur Advisors GP II, LLC, by Summit Master Company, its Sole Member, by /s/ Adam Hennessey, Member	05/29/2024
	Summit Partners GE IX, L.P., by Summit Partners GE IX, LLC, its General Partner, by Summit Partners, L.P., its Manager, by Summit Master Company, LLC, its General Partner, by /s/ Adam Hennessey, Member	05/29/2024
	Summit Partners GE IX, LLC, by Summit Partners, L.P., its Manager, by Summit Master Company, LLC, its General Partner, by /s/ Adam Hennessey, Member	05/29/2024
	Summit Investors Management, LLC, by Summit Master Company, LLC, its Managing Member, by /s/ Adam Hennessey, Member	05/29/2024
	** Signature of Reporting Person	Date
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