Summary of Significant Accounting Policies	3 Months Ended
Mar. 31, 2025
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	NOTE 2 SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES The Company's significant accounting policies are discussed in Note 2 "Summary of Significant Accounting Policies" in Item 15 of its Annual Report on Form 10-K for the year ended December 31, 2024. During the three months ended March 31, 2025, there have been no significant changes to these policies. Basis of Presentation and Principles of Consolidation The Company has prepared the accompanying unaudited consolidated financial statements pursuant to the rules and regulations of the SEC regarding interim financial reporting, which include the accounts of LifeStance, its wholly-owned subsidiaries and variable interest entities ("VIEs") in which LifeStance has an interest and is the primary beneficiary. Pursuant to these rules and regulations, the Company has omitted certain information and footnote disclosures it normally includes in its annual consolidated financial statements prepared in accordance with U.S. generally accepted accounting principles (“GAAP”). All intercompany balances and transactions have been eliminated in consolidation. In management’s opinion, the Company has made all adjustments (consisting only of normal, recurring adjustments, except as otherwise indicated) necessary to fairly state its consolidated financial condition, results of operations and cash flows. The Company’s interim period operating results do not necessarily indicate the results that may be expected for any other interim period or the full fiscal year. These financial statements and accompanying notes should be read in conjunction with the consolidated financial statements and notes thereto in the Company’s audited financial statements for the year ended December 31, 2024 in the Company's Annual Report on Form 10-K. Use of Accounting Estimates The preparation of consolidated financial statements in conformity with GAAP requires management to make a number of estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the consolidated financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates. Segment Information The Company has a single operating and reportable segment – mental health services. As the Company operates as one operating segment, all required segment financial information is found in the accompanying unaudited consolidated financial statements. The chief operating decision maker assesses performance for the mental health services segment and decides how to allocate resources based on net income (loss), which is reported on the accompanying unaudited consolidated statements of operations and comprehensive income (loss) as net income (loss). Net income (loss) is used to monitor budget versus actual results for assessment of segment performance. The chief operating decision maker considers budget-to-actual variances on a monthly basis when making decisions about allocating resources and assessing the performance of the segment. The chief operating decision maker utilizes consolidated expense information regularly provided in the budget-to-actual analysis in order to assist with assessing performance and deciding how to allocate resources, which align with the consolidated expense categories as disclosed on the face of the accompanying unaudited consolidated statements of operations and comprehensive income (loss). The measure of segment assets is reported on the accompanying consolidated balance sheets as total assets. The chief operating decision maker does not utilize total assets in the assessment of performance and allocation of resource decisions as the assessment and decisions are not made on the basis of total assets. Variable Interest Entities The Company evaluates its ownership, contractual and other interests in entities to determine if it has any variable interest in a VIE. These evaluations are complex, involve judgment, and the use of estimates and assumptions based on available information. If the Company determines that an entity in which it holds a contractual or ownership interest is a VIE and that the Company is the primary beneficiary, the Company consolidates such entity in its consolidated financial statements. The primary beneficiary of a VIE is the party that meets both of the following criteria: (i) has the power to make decisions that most significantly affect the economic performance of the VIE; and (ii) has the obligation to absorb losses or the right to receive benefits that in either case could potentially be significant to the VIE. The Company performs ongoing reassessments of whether changes in the facts and circumstances regarding the Company’s involvement with a VIE will cause the consolidation conclusion to change. The Company acquires and operates certain care centers which are deemed to be Friendly-Physician Entities (“FPEs”). As part of an FPE acquisition, the Company acquires 100% of the non-medical assets; however due to legal requirements the physician-owners must retain 100% of the equity interest. The Company’s agreements with FPEs generally consist of both a Management Service Agreement, which provides for various administrative and management services to be provided by the Company to the FPE, and Stock Transfer Restriction (“STR”) agreements with the physician-owners of the FPEs, which provide for the transition of ownership interests of the FPEs under certain conditions. The outstanding voting equity instruments of the FPEs are owned by the nominee shareholders appointed by the Company under the terms of the STR agreements. The Company has the right to receive income as an ongoing management fee, which effectively absorbs all of the residual interests and has also provided financial support through loans to the FPEs. The Company has exclusive responsibility for the provision of all nonmedical services including facilities, technology and intellectual property required for the day-to-day operation and management of each of the FPEs, and makes recommendations to the FPEs in establishing the guidelines for the employment and compensation of the physicians and other employees of the FPEs. In addition, the STR agreements provide that the Company has the right to designate an appropriately licensed person(s) to purchase the equity interest of the FPE for a nominal amount in the event of a succession event at the Company’s discretion. Based on the provisions of these agreements, the Company determined that the FPEs are VIEs due to the equity holder having insufficient capital at risk, and the Company has a variable interest in the FPEs. The contractual arrangements described above allow the Company to direct the activities that most significantly affect the economic performance of the FPEs. Accordingly, the Company is the primary beneficiary of the FPEs and consolidates the FPEs under the VIE model. Furthermore, as a direct result of nominal initial equity contributions by the physicians, the financial support the Company provides to the FPEs (e.g., loans) and the provisions of the contractual arrangements and nominee shareholder succession arrangements described above, the interests held by noncontrolling interest holders lack economic substance and do not provide them with the ability to participate in the residual profits or losses generated by the FPEs. Therefore, all income and expenses recognized by the FPEs are allocated to the Company. The Company does not hold interests in any VIEs for which the Company is not deemed to be the primary beneficiary. As noted previously, the Company acquires 100% of the non-medical assets of the VIEs. The aggregate carrying values of the VIEs' total assets and total liabilities not purchased by the Company but included on the consolidated balance sheets were not material at March 31, 2025 and December 31, 2024. Recent Accounting Pronouncements Not Yet Adopted In December 2023, the FASB issued ASU 2023-09, Income Taxes (Topic 740): Improvements to Income Tax Disclosures ("ASU 2023-09"). ASU 2023-09 improves the transparency of income tax disclosures by requiring (1) consistent categories and greater disaggregation of information in the rate reconciliation and (2) income taxes paid disaggregated by jurisdiction. ASU 2023-09 is effective for public business entities for annual periods beginning after December 15, 2024. Early adoption is permitted. ASU 2023-09 will apply on a prospective basis and retrospective application is permitted. The Company is in process of evaluating the impact of adoption of ASU 2023-09 on the Company's consolidated financial statements and disclosures. In November 2024, the FASB issued ASU 2024-03, Income Statement - Reporting Comprehensive Income - Expense Disaggregation Disclosures (Subtopic 220-40): Disaggregation of Income Statement Expenses ("ASU 2024-03"). ASU 2024-03 requires disclosure of additional information about specific expense categories in the notes to the financial statements. ASU 2024-03 is effective for public business entities for annual reporting periods beginning after December 15, 2026, and interim reporting periods within those fiscal years. Early adoption is permitted and should be applied either prospectively to financial statements issued for reporting periods after the effective date of ASU 2024-03 or retrospectively to any or all periods presented in the financial statements. The Company is in the process of evaluating the impact of the adoption of ASU 2024-03 on the Company's consolidated financial statements and disclosures.

The Company's significant accounting policies are discussed in Note 2 "Summary of Significant Accounting Policies" in Item 15 of its Annual Report on Form 10-K for the year ended December 31, 2024. During the three months ended March 31, 2025, there have been no significant changes to these policies.

Basis of Presentation and Principles of Consolidation

The Company has prepared the accompanying unaudited consolidated financial statements pursuant to the rules and regulations of the SEC regarding interim financial reporting, which include the accounts of LifeStance, its wholly-owned subsidiaries and variable interest entities ("VIEs") in which LifeStance has an interest and is the primary beneficiary. Pursuant to these rules and regulations, the Company has omitted certain information and footnote disclosures it normally includes in its annual consolidated financial statements prepared in accordance with U.S. generally accepted accounting principles (“GAAP”). All intercompany balances and transactions have been eliminated in consolidation. In management’s opinion, the Company has made all adjustments (consisting only of normal, recurring adjustments, except as otherwise indicated) necessary to fairly state its consolidated financial condition, results of operations and cash flows. The Company’s interim period operating results do not necessarily indicate the results that may be expected for any other interim period or the full fiscal year. These financial statements and accompanying notes should be read in conjunction with the consolidated financial statements and notes thereto in the Company’s audited financial statements for the year ended December 31, 2024 in the Company's Annual Report on Form 10-K.

Segment Information

The Company has a single operating and reportable segment – mental health services. As the Company operates as one operating segment, all required segment financial information is found in the accompanying unaudited consolidated financial statements.

The chief operating decision maker assesses performance for the mental health services segment and decides how to allocate resources based on net income (loss), which is reported on the accompanying unaudited consolidated statements of operations and comprehensive income (loss) as net income (loss). Net income (loss) is used to monitor budget versus actual results for assessment of segment performance. The chief operating decision maker considers budget-to-actual variances on a monthly basis when making decisions about allocating resources and assessing the performance of the segment. The chief operating decision maker utilizes consolidated expense information regularly provided in the budget-to-actual analysis in order to assist with assessing performance and deciding how to allocate resources, which align with the consolidated expense categories as disclosed on the face of the accompanying unaudited consolidated statements of operations and comprehensive income (loss).

The measure of segment assets is reported on the accompanying consolidated balance sheets as total assets. The chief operating decision maker does not utilize total assets in the assessment of performance and allocation of resource decisions as the assessment and decisions are not made on the basis of total assets.

Variable Interest Entities

The Company evaluates its ownership, contractual and other interests in entities to determine if it has any variable interest in a VIE. These evaluations are complex, involve judgment, and the use of estimates and assumptions based on available information. If the Company determines that an entity in which it holds a contractual or ownership interest is a VIE and that the Company is the primary beneficiary, the Company consolidates such entity in its consolidated financial statements. The primary beneficiary of a VIE is the party that meets both of the following criteria: (i) has the power to make decisions that most significantly affect the economic performance of the VIE; and (ii) has the obligation to absorb losses or the right to receive benefits that in either case could potentially

be significant to the VIE. The Company performs ongoing reassessments of whether changes in the facts and circumstances regarding the Company’s involvement with a VIE will cause the consolidation conclusion to change.

The Company acquires and operates certain care centers which are deemed to be Friendly-Physician Entities (“FPEs”). As part of an FPE acquisition, the Company acquires 100% of the non-medical assets; however due to legal requirements the physician-owners must retain 100% of the equity interest. The Company’s agreements with FPEs generally consist of both a Management Service Agreement, which provides for various administrative and management services to be provided by the Company to the FPE, and Stock Transfer Restriction (“STR”) agreements with the physician-owners of the FPEs, which provide for the transition of ownership interests of the FPEs under certain conditions. The outstanding voting equity instruments of the FPEs are owned by the nominee shareholders appointed by the Company under the terms of the STR agreements. The Company has the right to receive income as an ongoing management fee, which effectively absorbs all of the residual interests and has also provided financial support through loans to the FPEs. The Company has exclusive responsibility for the provision of all nonmedical services including facilities, technology and intellectual property required for the day-to-day operation and management of each of the FPEs, and makes recommendations to the FPEs in establishing the guidelines for the employment and compensation of the physicians and other employees of the FPEs. In addition, the STR agreements provide that the Company has the right to designate an appropriately licensed person(s) to purchase the equity interest of the FPE for a nominal amount in the event of a succession event at the Company’s discretion. Based on the provisions of these agreements, the Company determined that the FPEs are VIEs due to the equity holder having insufficient capital at risk, and the Company has a variable interest in the FPEs.

The contractual arrangements described above allow the Company to direct the activities that most significantly affect the economic performance of the FPEs. Accordingly, the Company is the primary beneficiary of the FPEs and consolidates the FPEs under the VIE model. Furthermore, as a direct result of nominal initial equity contributions by the physicians, the financial support the Company provides to the FPEs (e.g., loans) and the provisions of the contractual arrangements and nominee shareholder succession arrangements described above, the interests held by noncontrolling interest holders lack economic substance and do not provide them with the ability to participate in the residual profits or losses generated by the FPEs. Therefore, all income and expenses recognized by the FPEs are allocated to the Company. The Company does not hold interests in any VIEs for which the Company is not deemed to be the primary beneficiary.

As noted previously, the Company acquires 100% of the non-medical assets of the VIEs. The aggregate carrying values of the VIEs' total assets and total liabilities not purchased by the Company but included on the consolidated balance sheets were not material at March 31, 2025 and December 31, 2024.

Recent Accounting Pronouncements Not Yet Adopted

In December 2023, the FASB issued ASU 2023-09, Income Taxes (Topic 740): Improvements to Income Tax Disclosures ("ASU 2023-09"). ASU 2023-09 improves the transparency of income tax disclosures by requiring (1) consistent categories and greater disaggregation of information in the rate reconciliation and (2) income taxes paid disaggregated by jurisdiction. ASU 2023-09 is effective for public business entities for annual periods beginning after December 15, 2024. Early adoption is permitted. ASU 2023-09 will apply on a prospective basis and retrospective application is permitted. The Company is in process of evaluating the impact of adoption of ASU 2023-09 on the Company's consolidated financial statements and disclosures.

In November 2024, the FASB issued ASU 2024-03, Income Statement - Reporting Comprehensive Income - Expense Disaggregation Disclosures (Subtopic 220-40): Disaggregation of Income Statement Expenses ("ASU 2024-03"). ASU 2024-03 requires disclosure of additional information about specific expense categories in the notes to the financial statements. ASU 2024-03 is effective for public business entities for annual reporting periods beginning after December 15, 2026, and interim reporting periods within those fiscal years. Early adoption is permitted and should be applied either prospectively to financial statements issued for reporting periods after the effective date of ASU 2024-03 or retrospectively to any or all periods presented in the financial statements. The Company is in the process of evaluating the impact of the adoption of ASU 2024-03 on the Company's consolidated financial statements and disclosures.