# EDGAR Filing Document

**Accession Number:** 0001845257
**File Stem:** 0001193125-25-280127
**Filing Date:** 2025-11
**Character Count:** 19926
**Document Hash:** 09bd5b10a0cb4ee0aac1dc0803c8aae0
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001193125-25-280127.hdr.sgml**: 20251113

**ACCESSION NUMBER**: 0001193125-25-280127

**CONFORMED SUBMISSION TYPE**: SCHEDULE 13G/A

**PUBLIC DOCUMENT COUNT**: 1

**FILED AS OF DATE**: 20251113

**DATE AS OF CHANGE**: 20251113

**SUBJECT COMPANY**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** LifeStance Health Group, Inc.
- **CENTRAL INDEX KEY:** 0001845257
- **STANDARD INDUSTRIAL CLASSIFICATION:** SERVICES-HEALTH SERVICES [8000]
- **ORGANIZATION NAME:** 08 Industrial Applications and Services
- **EIN:** 000000000
- **STATE OF INCORPORATION:** DE
- **FISCAL YEAR END:** 1231

**FILING VALUES:**
- **FORM TYPE:** SCHEDULE 13G/A
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 005-93332
- **FILM NUMBER:** 251478306

**BUSINESS ADDRESS:**
- **STREET 1:** 4800 N. SCOTTSDALE ROAD
- **STREET 2:** SUITE 2500
- **CITY:** SCOTTSDALE
- **STATE:** AZ
- **ZIP:** 85251
- **BUSINESS PHONE:** 602-767-2100

**MAIL ADDRESS:**
- **STREET 1:** 4800 N. SCOTTSDALE ROAD
- **STREET 2:** SUITE 2500
- **CITY:** SCOTTSDALE
- **STATE:** AZ
- **ZIP:** 85251
**FILED BY**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** SUMMIT PARTNERS L P
- **CENTRAL INDEX KEY:** 0000830588

**ORGANIZATION NAME:**
- **EIN:** 043478657
- **STATE OF INCORPORATION:** DE
- **FISCAL YEAR END:** 1231

**FILING VALUES:**
- **FORM TYPE:** SCHEDULE 13G/A

**BUSINESS ADDRESS:**
- **STREET 1:** 222 BERKELEY STREET
- **STREET 2:** 18TH FLOOR
- **CITY:** BOSTON
- **STATE:** MA
- **ZIP:** 02116
- **BUSINESS PHONE:** 6178241094

**MAIL ADDRESS:**
- **STREET 1:** 222 BERKELEY STREET
- **STREET 2:** 18TH FLOOR
- **CITY:** BOSTON
- **STATE:** MA
- **ZIP:** 02116

### UNITED STATES SECURITIES AND EXCHANGE COMMISSION
**Washington, D.C. 20549**

## SCHEDULE 13G

### Under the Securities Exchange Act of 1934

**(Amendment No. 2)**

**Issuer:** LifeStance Health Group, Inc

**Title of Class of Securities:** Common Stock, par value $0.01 per share

**CUSIP Number:** 53228F101

**Date of Event Which Requires Filing of this Statement:** 09/30/2025

**Check the appropriate box to designate the rule pursuant to which this Schedule is filed:**

- [ ] Rule 13d-1(b)

- [ ] Rule 13d-1(c)

- [x] Rule 13d-1(d)

---

| 1. | Names of Reporting Persons<br>Summit Partners, L.P. | Names of Reporting Persons<br>Summit Partners, L.P. |
|:---|:---|:---|:---|
| 2. | Check the Appropriate Box if a Member of a Group (See Instructions)<br>(a) [ ] (b) [ ] | Check the Appropriate Box if a Member of a Group (See Instructions)<br>(a) [ ] (b) [ ] |
| 3. | SEC Use Only | SEC Use Only |
| 4. | Citizenship or Place of Organization<br>DE | Citizenship or Place of Organization<br>DE |
| Number of<br>Shares<br>Beneficially<br>Owned by<br>Each<br>Reporting<br>Person<br>With | 5. | Sole Voting Power<br>0 |
| Number of<br>Shares<br>Beneficially<br>Owned by<br>Each<br>Reporting<br>Person<br>With | 6. | Shared Voting Power<br>33524715 |
| Number of<br>Shares<br>Beneficially<br>Owned by<br>Each<br>Reporting<br>Person<br>With | 7. | Sole Dispositive Power<br>0 |
| Number of<br>Shares<br>Beneficially<br>Owned by<br>Each<br>Reporting<br>Person<br>With | 8. | Shared Dispositive Power<br>33524715 |
| 9. | Aggregate Amount Beneficially Owned by Each Reporting Person<br>33524715 | Aggregate Amount Beneficially Owned by Each Reporting Person<br>33524715 |
| 10. | Check if the Aggregate Amount in Row (9) Excludes Certain Shares (See Instructions) [ ] | Check if the Aggregate Amount in Row (9) Excludes Certain Shares (See Instructions) [ ] |
| 11. | Percent of Class Represented by Amount in Row (9)<br>8.62% | Percent of Class Represented by Amount in Row (9)<br>8.62% |
| 12. | Type of Reporting Person (See Instructions)<br>PN | Type of Reporting Person (See Instructions)<br>PN |

**Comment for Type of Reporting Person:** Calculated based on 389,000,281 shares of common stock, par value $0.01 per share ("Common Stock") outstanding as of October 29, 2025, as reported on the Issuer's Form 10-Q, filed with the Securities and Exchange Commision ("SEC") on November 6, 2025.

---

| 1. | Names of Reporting Persons<br>Summit Partners Growth Equity Fund IX-A, L.P. | Names of Reporting Persons<br>Summit Partners Growth Equity Fund IX-A, L.P. |
|:---|:---|:---|:---|
| 2. | Check the Appropriate Box if a Member of a Group (See Instructions)<br>(a) [ ] (b) [ ] | Check the Appropriate Box if a Member of a Group (See Instructions)<br>(a) [ ] (b) [ ] |
| 3. | SEC Use Only | SEC Use Only |
| 4. | Citizenship or Place of Organization<br>DE | Citizenship or Place of Organization<br>DE |
| Number of<br>Shares<br>Beneficially<br>Owned by<br>Each<br>Reporting<br>Person<br>With | 5. | Sole Voting Power<br>0 |
| Number of<br>Shares<br>Beneficially<br>Owned by<br>Each<br>Reporting<br>Person<br>With | 6. | Shared Voting Power<br>20529149 |
| Number of<br>Shares<br>Beneficially<br>Owned by<br>Each<br>Reporting<br>Person<br>With | 7. | Sole Dispositive Power<br>0 |
| Number of<br>Shares<br>Beneficially<br>Owned by<br>Each<br>Reporting<br>Person<br>With | 8. | Shared Dispositive Power<br>20529149 |
| 9. | Aggregate Amount Beneficially Owned by Each Reporting Person<br>20529149 | Aggregate Amount Beneficially Owned by Each Reporting Person<br>20529149 |
| 10. | Check if the Aggregate Amount in Row (9) Excludes Certain Shares (See Instructions) [ ] | Check if the Aggregate Amount in Row (9) Excludes Certain Shares (See Instructions) [ ] |
| 11. | Percent of Class Represented by Amount in Row (9)<br>5.28% | Percent of Class Represented by Amount in Row (9)<br>5.28% |
| 12. | Type of Reporting Person (See Instructions)<br>PN | Type of Reporting Person (See Instructions)<br>PN |

**Comment for Type of Reporting Person:** Calculated based on 389,000,281 shares of Common Stock as of October 29, 2025, as reported on the Issuer's Form 10-Q, filed with the SEC on November 6, 2025.

---

| 1. | Names of Reporting Persons<br>Summit Partners Growth Equity Fund IX-B, L.P. | Names of Reporting Persons<br>Summit Partners Growth Equity Fund IX-B, L.P. |
|:---|:---|:---|:---|
| 2. | Check the Appropriate Box if a Member of a Group (See Instructions)<br>(a) [ ] (b) [ ] | Check the Appropriate Box if a Member of a Group (See Instructions)<br>(a) [ ] (b) [ ] |
| 3. | SEC Use Only | SEC Use Only |
| 4. | Citizenship or Place of Organization<br>DE | Citizenship or Place of Organization<br>DE |
| Number of<br>Shares<br>Beneficially<br>Owned by<br>Each<br>Reporting<br>Person<br>With | 5. | Sole Voting Power<br>0 |
| Number of<br>Shares<br>Beneficially<br>Owned by<br>Each<br>Reporting<br>Person<br>With | 6. | Shared Voting Power<br>12818117 |
| Number of<br>Shares<br>Beneficially<br>Owned by<br>Each<br>Reporting<br>Person<br>With | 7. | Sole Dispositive Power<br>0 |
| Number of<br>Shares<br>Beneficially<br>Owned by<br>Each<br>Reporting<br>Person<br>With | 8. | Shared Dispositive Power<br>12818117 |
| 9. | Aggregate Amount Beneficially Owned by Each Reporting Person<br>12818117 | Aggregate Amount Beneficially Owned by Each Reporting Person<br>12818117 |
| 10. | Check if the Aggregate Amount in Row (9) Excludes Certain Shares (See Instructions) [ ] | Check if the Aggregate Amount in Row (9) Excludes Certain Shares (See Instructions) [ ] |
| 11. | Percent of Class Represented by Amount in Row (9)<br>3.30% | Percent of Class Represented by Amount in Row (9)<br>3.30% |
| 12. | Type of Reporting Person (See Instructions)<br>PN | Type of Reporting Person (See Instructions)<br>PN |

**Comment for Type of Reporting Person:** Calculated based on 389,000,281 shares of Common Stock as of October 29, 2025, as reported on the Issuer's Form 10-Q, filed with the SEC on November 6, 2025.

---

| 1. | Names of Reporting Persons<br>Summit Investors GE IX/VC IV (UK), L.P. | Names of Reporting Persons<br>Summit Investors GE IX/VC IV (UK), L.P. |
|:---|:---|:---|:---|
| 2. | Check the Appropriate Box if a Member of a Group (See Instructions)<br>(a) [ ] (b) [ ] | Check the Appropriate Box if a Member of a Group (See Instructions)<br>(a) [ ] (b) [ ] |
| 3. | SEC Use Only | SEC Use Only |
| 4. | Citizenship or Place of Organization<br>E9 | Citizenship or Place of Organization<br>E9 |
| Number of<br>Shares<br>Beneficially<br>Owned by<br>Each<br>Reporting<br>Person<br>With | 5. | Sole Voting Power<br>0 |
| Number of<br>Shares<br>Beneficially<br>Owned by<br>Each<br>Reporting<br>Person<br>With | 6. | Shared Voting Power<br>14991 |
| Number of<br>Shares<br>Beneficially<br>Owned by<br>Each<br>Reporting<br>Person<br>With | 7. | Sole Dispositive Power<br>0 |
| Number of<br>Shares<br>Beneficially<br>Owned by<br>Each<br>Reporting<br>Person<br>With | 8. | Shared Dispositive Power<br>14991 |
| 9. | Aggregate Amount Beneficially Owned by Each Reporting Person<br>14991 | Aggregate Amount Beneficially Owned by Each Reporting Person<br>14991 |
| 10. | Check if the Aggregate Amount in Row (9) Excludes Certain Shares (See Instructions) [ ] | Check if the Aggregate Amount in Row (9) Excludes Certain Shares (See Instructions) [ ] |
| 11. | Percent of Class Represented by Amount in Row (9)<br>0.01% | Percent of Class Represented by Amount in Row (9)<br>0.01% |
| 12. | Type of Reporting Person (See Instructions)<br>PN | Type of Reporting Person (See Instructions)<br>PN |

**Comment for Type of Reporting Person:** Calculated based on 389,000,281 shares of Common Stock as of October 29, 2025, as reported on the Issuer's Form 10-Q, filed with the SEC on November 6, 2025.

---

| 1. | Names of Reporting Persons<br>Summit Partners Entrepreneur Advisors Fund II, L.P. | Names of Reporting Persons<br>Summit Partners Entrepreneur Advisors Fund II, L.P. |
|:---|:---|:---|:---|
| 2. | Check the Appropriate Box if a Member of a Group (See Instructions)<br>(a) [ ] (b) [ ] | Check the Appropriate Box if a Member of a Group (See Instructions)<br>(a) [ ] (b) [ ] |
| 3. | SEC Use Only | SEC Use Only |
| 4. | Citizenship or Place of Organization<br>DE | Citizenship or Place of Organization<br>DE |
| Number of<br>Shares<br>Beneficially<br>Owned by<br>Each<br>Reporting<br>Person<br>With | 5. | Sole Voting Power<br>0 |
| Number of<br>Shares<br>Beneficially<br>Owned by<br>Each<br>Reporting<br>Person<br>With | 6. | Shared Voting Power<br>19157 |
| Number of<br>Shares<br>Beneficially<br>Owned by<br>Each<br>Reporting<br>Person<br>With | 7. | Sole Dispositive Power<br>0 |
| Number of<br>Shares<br>Beneficially<br>Owned by<br>Each<br>Reporting<br>Person<br>With | 8. | Shared Dispositive Power<br>19157 |
| 9. | Aggregate Amount Beneficially Owned by Each Reporting Person<br>19157 | Aggregate Amount Beneficially Owned by Each Reporting Person<br>19157 |
| 10. | Check if the Aggregate Amount in Row (9) Excludes Certain Shares (See Instructions) [ ] | Check if the Aggregate Amount in Row (9) Excludes Certain Shares (See Instructions) [ ] |
| 11. | Percent of Class Represented by Amount in Row (9)<br>0.01% | Percent of Class Represented by Amount in Row (9)<br>0.01% |
| 12. | Type of Reporting Person (See Instructions)<br>PN | Type of Reporting Person (See Instructions)<br>PN |

**Comment for Type of Reporting Person:** Calculated based on 389,000,281 shares of Common Stock as of October 29, 2025, as reported on the Issuer's Form 10-Q, filed with the SEC on November 6, 2025.

---

| 1. | Names of Reporting Persons<br>Summit Investors GE IX/VC IV, LLC | Names of Reporting Persons<br>Summit Investors GE IX/VC IV, LLC |
|:---|:---|:---|:---|
| 2. | Check the Appropriate Box if a Member of a Group (See Instructions)<br>(a) [ ] (b) [ ] | Check the Appropriate Box if a Member of a Group (See Instructions)<br>(a) [ ] (b) [ ] |
| 3. | SEC Use Only | SEC Use Only |
| 4. | Citizenship or Place of Organization<br>DE | Citizenship or Place of Organization<br>DE |
| Number of<br>Shares<br>Beneficially<br>Owned by<br>Each<br>Reporting<br>Person<br>With | 5. | Sole Voting Power<br>0 |
| Number of<br>Shares<br>Beneficially<br>Owned by<br>Each<br>Reporting<br>Person<br>With | 6. | Shared Voting Power<br>143301 |
| Number of<br>Shares<br>Beneficially<br>Owned by<br>Each<br>Reporting<br>Person<br>With | 7. | Sole Dispositive Power<br>0 |
| Number of<br>Shares<br>Beneficially<br>Owned by<br>Each<br>Reporting<br>Person<br>With | 8. | Shared Dispositive Power<br>143301 |
| 9. | Aggregate Amount Beneficially Owned by Each Reporting Person<br>143301 | Aggregate Amount Beneficially Owned by Each Reporting Person<br>143301 |
| 10. | Check if the Aggregate Amount in Row (9) Excludes Certain Shares (See Instructions) [ ] | Check if the Aggregate Amount in Row (9) Excludes Certain Shares (See Instructions) [ ] |
| 11. | Percent of Class Represented by Amount in Row (9)<br>0.04% | Percent of Class Represented by Amount in Row (9)<br>0.04% |
| 12. | Type of Reporting Person (See Instructions)<br>OO | Type of Reporting Person (See Instructions)<br>OO |

**Comment for Type of Reporting Person:** Calculated based on 389,000,281 shares of Common Stock as of October 29, 2025, as reported on the Issuer's Form 10-Q, filed with the SEC on November 6, 2025.

---

**Item 1(a). Name of Issuer:**
LifeStance Health Group, Inc

**Item 1(b). Address of Issuer's Principal Executive Offices:**
4800 N. Scottsdale Road, Suite 6000 Scottsdale, Arizona 85251

**Item 2(a). Name of Person Filing:**
This statement is filed by the entities and persons listed below, all of whom together are referred to herein as the "Reporting Persons":

 	(i)	Summit Partners, L.P.;
 	(ii)	Summit Partners Growth Equity Fund IX-A, L.P.;
        (iii)	Summit Partners Growth Equity Fund IX-B, L.P.;
        (iv)	Summit Investors GE IX/VC IV (UK), L.P.;
        (v)	Summit Partners Entrepreneur Advisors Fund II, L.P.; and
        (vi)	Summit Investors GE IX/VC IV, LLC

**Item 2(b). Address of Principal Business Office:**
222 Berkeley Street, 18th Floor
Boston, MA 02116

**Item 2(c). Citizenship:**
See response to Item 4 on each cover page

**Item 2(d). Title of Class of Securities:**
Common Stock, par value $0.01 per share

**Item 2(e). CUSIP Number:**
53228F101

**Item 3. If this statement is filed pursuant to §§ 240.13d-1(b) or 240.13d-2(b) or (c), check whether the person filing is a:**

(a) [ ] Broker or dealer registered under section 15 of the Act (15 U.S.C. 78o).

(b) [ ] Bank as defined in section 3(a)(6) of the Act (15 U.S.C. 78c).

(c) [ ] Insurance company as defined in section 3(a)(19) of the Act (15 U.S.C. 78c).

(d) [ ] Investment company registered under section 8 of the Investment Company Act of 1940 (15 U.S.C. 80a-8).

(e) [ ] An investment adviser in accordance with § 240.13d-1(b)(1)(ii)(E);

(f) [ ] An employee benefit plan or endowment fund in accordance with § 240.13d-1(b)(1)(ii)(F);

(g) [ ] A parent holding company or control person in accordance with § 240.13d-1(b)(1)(ii)(G);

(h) [ ] A savings associations as defined in Section 3(b) of the Federal Deposit Insurance Act (12 U.S.C. 1813);

(i) [ ] A church plan that is excluded from the definition of an investment company under section 3(c)(14) of the Investment Company Act of 1940 (15 U.S.C. 80a-3);

(j) [ ] A non-U.S. institution in accordance with § 240.13d-1(b)(1)(ii)(J), if filing as a non-U.S. institution in accordance with § 240.13d-1(b)(1)(ii)(J), please specify the type of institution:

(k) [ ] Group, in accordance with Rule 240.13d-1(b)(1)(ii)(K).

**Item 4. Ownership:**

**(a) Amount beneficially owned:**

See responses to Item 9 on each cover page.

**(b) Percent of class:**

See responses to Item 11 on each cover page.

**(c) Number of shares as to which the person has:**

**(i) Sole power to vote or to direct the vote:**

See responses to Item 5 on each cover page.

**(ii) Shared power to vote or to direct the vote:**

See responses to Item 6 on each cover page.

**(iii) Sole power to dispose or to direct the disposition of:**

See responses to Item 7 on each cover page.

**(iv) Shared power to dispose or to direct the disposition of:**

See response to Item 8 on each cover page.
Summit Partners, L.P. is the managing member of Summit Partners GE IX, LLC, which is general partner of Summit Partners GE IX, L.P., 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 general partner of Summit Partners L.P., which is the manager 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. Summit Master Company, LLC, as the sole member of Summit Partners Entrepreneur Advisors GP II, LLC, the managing member of Summit Investors Management, LLC and general partner of Summit Partners, L.P., 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 the reported securities held by Summit Partners, L.P., through a four-person investment committee. Peter Y. Chung, Darren M. Black, Mark A. deLaar and Craig D. Frances are the current members of the investment committee, and as such may be deemed to have voting and dispositive authority over the reported securities, but each of the foregoing disclaim such beneficial ownership. This Statement shall not be construed as an admission that the Reporting Persons or any of the members of the investment committee are, for the purpose of Section 13(d) or 13(g) of the Exchange Act, the beneficial owner of any securities covered by this Statement.

**Item 5. Ownership of Five Percent or Less of a Class.**

[x] If this statement is being filed to report the fact that as of the date hereof the reporting person has ceased to be the beneficial owner of more than five percent of the class of securities, check the following.

**Item 6. Ownership of More than 5 Percent on Behalf of Another Person.**

Not Applicable

**Item 7. Identification and Classification of the Subsidiary**

Not Applicable

**Item 8. Identification and Classification of Members of the Group**

Not Applicable

**Item 9. Notice of Dissolution of Group**

Not Applicable

**Item 10. Certification:**

—

### SIGNATURE

After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.

**Summit Partners, L.P.**

**Date:** 11/13/2025

**By:** By: Summit Master Company, LLC / /s/ Adam H. Hennessey, as POA

**Name & Title:** Its: General Partner / Adam H. Hennessey, as Power of Attorney

**Summit Partners Growth Equity Fund IX-A, L.P.**

**Date:** 11/13/2025

**By:** By: Summit Partners GE IX, L.P. / /s/ Adam H. Hennessey, as POA

**Name & Title:** Its: General Partner / Adam H. Hennessey, as Power of Attorney

**Summit Partners Growth Equity Fund IX-B, L.P.**

**Date:** 11/13/2025

**By:** By: Summit Partners GE IX, L.P. / /s/ Adam H. Hennessey, as POA

**Name & Title:** Its: General Partner / Adam H. Hennessey, as Power of Attorney

**Summit Investors GE IX/VC IV (UK), L.P.**

**Date:** 11/13/2025

**By:** By: Summit Investors Management, LLC / /s/ Adam H. Hennessey, as POA

**Name & Title:** Its: Manager  / Adam H. Hennessey, as Power of Attorney

**Summit Partners Entrepreneur Advisors Fund II, L.P.**

**Date:** 11/13/2025

**By:** By: Summit Investors Management, LLC / /s/ Adam H. Hennessey, as POA

**Name & Title:** Its: Manager  / Adam H. Hennessey, as Power of Attorney

**Summit Investors GE IX/VC IV, LLC**

**Date:** 11/13/2025

**By:** By: Summit Partners Entrepreneur Advisors GP II, LLC / /s/ Adam H. Hennessey, as POA

**Name & Title:** Its: General Partner / Adam H. Hennessey, Power of Attorney