LifeStance Health (LFST) 10-Q 9 Nov 22 2022 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2022	Nov. 01, 2022
Cover [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 30, 2022
Entity Registrant Name	LifeStance Health Group, Inc.
Entity Central Index Key	0001845257
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Small Business	false
Entity Emerging Growth Company	true
Entity Shell Company	false
Document Quarterly Report	true
Document Transition Report	false
Document Fiscal Year Focus	2022
Document Fiscal Period Focus	Q3
Trading Symbol	LFST
Title of 12(b) Security	Common Stock, par value $0.01 per share
Security Exchange Name	NASDAQ
Entity Ex Transition Period	false
Entity Common Stock, Shares Outstanding		375,986,406
Entity File Number	001-40478
Entity Tax Identification Number	86-1832801
Entity Address, Address Line Two	Suite 6000
Entity Incorporation, State or Country Code	DE
Entity Address, Address Line One	4800 N. Scottsdale Road
Entity Address, City or Town	Scottsdale
Entity Address, State or Province	AZ
Entity Address, Postal Zip Code	85251
City Area Code	602
Local Phone Number	767-2100

CONSOLIDATED BALANCE SHEETS (un

CONSOLIDATED BALANCE SHEETS (unaudited) - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
CURRENT ASSETS
Cash and cash equivalents	$ 90,336	$ 148,029
Patient accounts receivable, net	113,284	76,078
Prepaid expenses and other current assets	48,967	42,413
Total current assets	252,587	266,520
NONCURRENT ASSETS
Property and equipment, net	193,393	152,242
Intangible assets, net	272,473	300,355
Goodwill	1,249,793	1,204,544
Other noncurrent assets	11,416	3,448
Total noncurrent assets	1,727,075	1,660,589
Total assets	1,979,662	1,927,109
CURRENT LIABILITIES
Accounts payable	7,947	14,152
Accrued payroll expenses	61,576	60,002
Other accrued expenses	29,303	26,510
Current portion of contingent consideration	10,816	14,123
Other current liabilities	2,630	1,965
Total current liabilities	112,272	116,752
NONCURRENT LIABILITIES
Long-term debt, net	212,042	157,416
Other noncurrent liabilities	66,956	50,325
Contingent consideration, net of current portion	1,481	3,307
Deferred tax liability, net	55,408	54,281
Total noncurrent liabilities	335,887	265,329
Total liabilities	448,159	382,081
COMMITMENT AND CONTINGENCIES (see Note 14)
STOCKHOLDERS' EQUITY
Preferred stock - par value $0.01 per share; 25,000 shares authorized as of September 30, 2022 and December 31, 2021; 0 shares issued and outstanding as of September 30, 2022 and December 31, 2021	0	0
Common stock - par value $0.01 per share; 800,000 shares authorized as of September 30, 2022 and December 31, 2021; 376,042 and 374,255 shares issued and outstanding as of September 30, 2022 and December 31, 2021, respectively	3,761	3,743
Additional paid-in capital	2,050,537	1,898,357
Accumulated other comprehensive income	3,185	0
Accumulated deficit	(525,980)	(357,072)
Total stockholders' equity	1,531,503	1,545,028
Total liabilities and stockholders' equity	$ 1,979,662	$ 1,927,109

CONSOLIDATED BALANCE SHEETS (_2

CONSOLIDATED BALANCE SHEETS (unaudited) (Parenthetical) - $ / shares	Sep. 30, 2022	Dec. 31, 2021
Preferred Stock, par value	$ 0.01	$ 0.01
Preferred Stock, Shares Authorized	25,000,000	25,000,000
Preferred Stock, Shares Issued	0	0
Preferred Stock, Shares Outstanding	0	0
Common Stock, par value	$ 0.01	$ 0.01
Common Stock, Shares Authorized	800,000,000	800,000,000
Common Stock, Shares, Issued	376,042,000	374,255,000
Common Stock, Shares, Outstanding	376,042,000	374,255,000

CONSOLIDATED STATEMENTS OF OPER

CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS (unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
TOTAL REVENUE	$ 217,560	$ 173,835	$ 630,182	$ 477,516
OPERATING EXPENSES
Center costs, excluding depreciation and amortization shown separately below	157,267	121,783	455,857	330,258
General and administrative expenses	81,248	162,943	288,176	281,073
Depreciation and amortization	17,884	13,777	50,311	38,779
Total operating expenses	256,399	298,503	794,344	650,110
LOSS FROM OPERATIONS	(38,839)	(124,668)	(164,162)	(172,594)
OTHER INCOME (EXPENSE)
Gain (loss) on remeasurement of contingent consideration	1,176	(906)	562	(1,463)
Transaction costs	(210)	(126)	(507)	(3,656)
Interest expense	(4,189)	(3,503)	(14,763)	(35,309)
Other expense	(144)	0	(144)	(1,445)
Total other expense	(3,367)	(4,535)	(14,852)	(41,873)
LOSS BEFORE INCOME TAXES	(42,206)	(129,203)	(179,014)	(214,467)
INCOME TAX BENEFIT	4,353	8,751	10,106	15,300
NET LOSS	(37,853)	(120,452)	(168,908)	(199,167)
Accretion of redeemable class A units	0	0	0	(36,750)
NET LOSS AVAILABLE TO COMMON STOCKHOLDERS/MEMBERS	$ (37,853)	$ (120,452)	$ (168,908)	$ (235,917)
NET LOSS PER SHARE, BASIC	$ (0.11)	$ (0.35)	$ (0.48)	$ (0.73)
NET LOSS PER SHARE, DILUTED	$ (0.11)	$ (0.35)	$ (0.48)	$ (0.73)
Weighted-average shares used to compute basic and diluted net loss per share	357,520	343,394	354,057	321,283
Net loss	$ (37,853)	$ (120,452)	$ (168,908)	$ (199,167)
OTHER COMPREHENSIVE INCOME
Unrealized gains on cash flow hedge, net of tax	3,185		3,185
COMPREHENSIVE LOSS	$ (34,668)	$ (120,452)	$ (165,723)	$ (199,167)

CONSOLIDATED STATEMENTS OF CHAN

CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY AND REDEEMABLE UNITS AND STOCKHOLDER'S / MEMBERS' EQUITY - USD ($) $ in Thousands	Total	IPO [Member]	Class A Redeemable Units [Member]	Class A-1 Common Units [Member]	Class A-2 Common Units [Member]	Class B Common Units [Member]	Common Stock [Member]	Common Stock [Member] IPO [Member]	Common Stock [Member] Class A-1 Common Units [Member]	Common Stock [Member] Class A-2 Common Units [Member]	Common Stock [Member] Class B Common Units [Member]	Additional Paid-in Capital [Member]	Additional Paid-in Capital [Member] IPO [Member]	Accumulated Other Comprehensive Income Member	Accumulated Deficit [Member]
Balance at Dec. 31, 2020	$ 997,836						$ 0		$ 959,563	$ 49,946	$ 0	$ 1,452			$ (13,125)
Temporary Equity, Shares Outstanding at Dec. 31, 2020			35,000
Temporary Equity, Carrying Amount, Attributable to Parent at Dec. 31, 2020			$ 35,000
Shares, Outstanding at Dec. 31, 2020				959,563	49,946	0	0
Net loss	(199,167)														(199,167)
Issuance of common units	1,000	$ 548,905			$ 1,000			$ 328					$ 548,577
Issuance of common , Shares					962			32,800
Accretion of redeemable class A units	(36,750)		(36,750)												(36,750)
Issuance of common units for acquisitions of businesses	1,486				$ 1,486
Issuance of common units for acquisitions of businesses, shares					725
Vested class B profits interests						17,920
Conversion of Redeemable Class A Units into common stock upon closing of initial public offering, Value	71,750		$ (71,750)				$ 102					71,648
Conversion of Redeemable Class A Units into common stock upon closing of initial public offering, Shares			(35,000)				10,234
Conversion of common units into common stock upon closing of initial public offering, Value				$ (959,563)	$ (52,432)		$ 2,957					1,009,038
Conversion of common units into common stock upon closing of initial public offering, Shares				(959,563)	(51,633)		295,663
Conversion of vested Class B Profits Interests to common stock upon closing of initial public offering						(17,920)	4,186
Conversion of vested class B profits interests to common stock upon closing of initial public offering, value							$ 42					(42)
Conversion of unvested class B profits interests to common stock upon closing of initial public offering, value							$ 308					(308)
Conversion of unvested class profits interests to common stock upon closing of initial public offering , shares							30,766
Endowment of shares to the LifeStance Health Foundation, shares							500
Endowment of shares to the LifeStance Health Foundation, value	9,000						$ 5					8,995
Stock and unit-based compensation expense	150,809											150,809
Balance at Sep. 30, 2021	1,544,869						$ 3,742		0	0	0	1,790,169			(249,042)
Temporary Equity, Shares Outstanding at Sep. 30, 2021			0
Temporary Equity, Carrying Amount, Attributable to Parent at Sep. 30, 2021			$ 0
Shares, Outstanding at Sep. 30, 2021				0	0	0	374,149
Balance at Jun. 30, 2021	1,544,632						$ 3,742					1,669,480			(128,590)
Shares, Outstanding at Jun. 30, 2021							374,149
Net loss	(120,452)														(120,452)
Accretion of redeemable class A units	0
Stock and unit-based compensation expense	120,689											120,689
Balance at Sep. 30, 2021	1,544,869						$ 3,742		$ 0	$ 0	$ 0	1,790,169			(249,042)
Temporary Equity, Shares Outstanding at Sep. 30, 2021			0
Temporary Equity, Carrying Amount, Attributable to Parent at Sep. 30, 2021			$ 0
Shares, Outstanding at Sep. 30, 2021				0	0	0	374,149
Balance at Dec. 31, 2021	1,545,028						$ 3,743					1,898,357		$ 0	(357,072)
Shares, Outstanding at Dec. 31, 2021							374,255
Net loss	(168,908)														(168,908)
Issuance of common stock upon vesting of restricted stock units	(37)						$ 20					(57)
Issuance of common stock upon vesting of restricted stock units, Shares							2,000
Forfeitures, value	(1,050)						$ (2)					(1,048)
Forfeitures, shares							213
Other comprehensive income	3,185													3,185
Accretion of redeemable class A units	0
Issuance of common units for acquisitions of businesses	0
Stock and unit-based compensation expense	153,285											153,285
Balance at Sep. 30, 2022	1,531,503						$ 3,761					2,050,537		3,185	(525,980)
Shares, Outstanding at Sep. 30, 2022							376,042
Balance at Jun. 30, 2022	1,531,301						$ 3,763					2,015,665		0	(488,127)
Shares, Outstanding at Jun. 30, 2022							376,181
Net loss	(37,853)														(37,853)
Issuance of common stock upon vesting of restricted stock units, Shares							46
Forfeitures, value	(865)						$ (2)					(863)
Forfeitures, shares							185
Other comprehensive income	3,185													3,185
Accretion of redeemable class A units	0
Stock and unit-based compensation expense	35,735											35,735
Balance at Sep. 30, 2022	$ 1,531,503						$ 3,761					$ 2,050,537		$ 3,185	$ (525,980)
Shares, Outstanding at Sep. 30, 2022							376,042

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS (unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021
CASH FLOWS FROM OPERATING ACTIVITIES
Net loss	$ (168,908)	$ (199,167)
Adjustments to reconcile net loss to net cash provided by (used in) operating activities:
Depreciation and amortization	50,311	38,779
Stock and unit-based compensation	152,235	150,809
Loss on debt extinguishment	3,380	5,620
Amortization of discount and debt issue costs	1,351	1,498
(Gain) loss on remeasurement of contingent consideration	(562)	1,463
Loss on disposal of assets	144	0
Endowment of shares to LifeStance Health Foundation	0	9,000
Change in operating assets and liabilities, net of businesses acquired:
Patient accounts receivable, net	(34,606)	(20,711)
Prepaid expenses and other current assets	(5,811)	(32,888)
Accounts payable	1,109	(4,613)
Accrued payroll expenses	(588)	15,910
Other accrued expenses	18,816	13,085
Net cash provided by (used in) operating activities	16,871	(21,215)
CASH FLOWS FROM INVESTING ACTIVITIES
Purchases of property and equipment	(68,871)	(55,815)
Acquisitions of businesses, net of cash acquired	(40,294)	(58,699)
Net cash used in investing activities	(109,165)	(114,514)
CASH FLOWS FROM FINANCING ACTIVITIES
Proceeds from initial public offering, net of underwriters discounts and commissions and deferred offering costs	0	548,905
Issuance of common units to new investors	0	1,000
Proceeds from long-term debt, net of discount	237,474	98,800
Payments of debt issue costs	(7,266)	(2,360)
Payments of long-term debt	(181,230)	(311,060)
Prepayment for debt paydown	(1,609)	0
Payments of contingent consideration	(12,290)	(6,262)
Taxes related to net share settlement of equity awards	(478)	0
Net cash provided by financing activities	34,601	329,023
NET (DECREASE) INCREASE IN CASH AND CASH EQUIVALENTS	(57,693)	193,294
Cash and Cash Equivalents - Beginning of period	148,029	18,829
CASH AND CASH EQUIVALENTS – END OF PERIOD	90,336	212,123
SUPPLEMENTAL DISCLOSURE OF CASH FLOW INFORMATION
Cash paid for interest	9,518	28,217
Cash paid for taxes, net of refunds	1,780	908
SUPPLEMENTAL DISCLOSURES OF NON CASH INVESTING AND FINANCING ACTIVITIES
Equipment financed through capital leases	264	14
Contingent consideration incurred in acquisitions of businesses	7,719	5,514
Acquisition of property and equipment included in liabilities	8,607	8,936
Issuance of common units for acquisitions of businesses	$ 0	$ 1,486

Nature of the Business

Nature of the Business	9 Months Ended
	Sep. 30, 2022
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Nature of the Business	NOTE 1 NATURE OF THE BUSINESS Description of Business LifeStance Health Group, Inc. (“LifeStance Health Group”) was formed as a Delaware corporation on January 28, 2021 for the purpose of completing an initial public offering (“IPO”) and related transactions in order to carry on the business of LifeStance TopCo, L.P. (“LifeStance TopCo”) and subsidiaries. LifeStance Health Group is the sole equity holder of LifeStance TopCo and operates and controls all of the business and affairs. As a result, LifeStance Health Group consolidates the financial results of LifeStance TopCo, its wholly-owned subsidiaries and variable interest entities. LifeStance Health Group and LifeStance TopCo are collectively referred to herein as the “Company”, "LifeStance" or "LifeStance Health". The Company operates as a provider of outpatient mental health services, spanning psychiatric evaluations and treatment, psychological and neuropsychological testing, and individual, family and group therapy. Initial Public Offering On June 14, 2021, the Company completed its IPO in which it issued and sold 32,800 shares of common stock and affiliates of TPG Inc. ("TPG"), affiliates of Silversmith Capital Partners ("Silversmith"), and affiliates of Summit Partners ("Summit") (collectively, the "Selling Shareholders") sold 7,200 shares of common stock at an offering price of $ 18.00 per share. The Selling Shareholders granted the underwriters an option to purchase an additional 6,000 shares of common stock. The underwriters exercised in full their option to purchase additional shares, and the sale of the option shares was completed on June 25, 2021. The Company received net proceeds of $ 548,905 , after deducting underwriting discounts and commissions of $ 32,472 and deferred offering costs of $ 9,023 . The Company did not receive any proceeds from the sale of shares by the Selling Stockholders, including the option shares. Deferred, direct offering costs were capitalized and consisted of fees and expenses incurred in connection with the sale of the Company’s common stock in the IPO, including legal, accounting, printing and other offering related costs. Upon completion of the IPO, these deferred offering costs were reclassified from current assets to stockholders’ equity and recorded against the net proceeds from the offering. Prior to the IPO, each of the holders of partnership interests in LifeStance TopCo contributed its partnership interests to LifeStance Health Group in exchange for shares of common stock (including shares of common stock issued as restricted stock subject to vesting) of LifeStance Health Group (the "Organizational Transactions"). Following the contribution of partnership interests, LifeStance TopCo became wholly-owned by LifeStance Health Group. The number of shares of common stock that each such holder of partnership interests in LifeStance TopCo received was determined based on the value that such holder would have received under the distribution provisions of the limited partnership agreement of LifeStance TopCo, with shares of common stock valued by reference to the IPO price. All 1,046,196 of LifeStance TopCo’s outstanding redeemable and common Class A units and 152,620 Class B units (the "Class B Common Units", "Profits Interests Units" or "Profits Interests") were contributed in exchange for 310,083 shares of common stock of LifeStance Health Group plus 30,766 shares of common stock issued as restricted stock ("RSAs") subject to vesting. In connection with the IPO, the Company established the LifeStance Health Foundation, a non-profit organization that focuses on youth mental health, and the mental health of underrepresented minority communities, the underemployed and the uninsured. Concurrently with the closing of the IPO, the Company endowed the LifeStance Health Foundation through a combination of $ 1,000 in cash and 500 shares of its common stock, representing aggregate cash and equity value of $ 10,000 . Following the effective date of the IPO, LifeStance Health Group consolidates the financial results of LifeStance TopCo, its wholly-owned subsidiaries and variable interest entities ("VIEs") and the financial statements for the periods prior to the IPO have been adjusted to combine the previously separate entities for presentation purposes. Prior to the IPO restructuring transactions, LifeStance Health Group had no operations.

Summary of Significant Accounti

Summary of Significant Accounting Policies	9 Months Ended
	Sep. 30, 2022
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, 2021. During the nine months ended September 30, 2022, there have been no significant changes to these policies other than the additions to the stock and unit-based compensation policy further described below. 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 Health Group, LifeStance TopCo, its wholly-owned subsidiaries and VIEs in which LifeStance TopCo 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, 2021 in the Company's Annual Report on Form 10-K. On May 14, 2020, affiliates of TPG acquired the majority of the equity interests of LifeStance Health Holdings, Inc. through certain newly formed subsidiaries ("TPG Acquisition"). Periods subsequent to the acquisition and prior to the IPO and restructuring transactions reflect the financial statements of LifeStance TopCo. Periods subsequent to the IPO and restructuring transactions reflect the financial statements of LifeStance Health Group. All periods subsequent to the TPG Acquisition have been presented as the financial statements of LifeStance Health Group. 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. 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 a 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 September 30, 2022 and December 31, 2021 . Stock and Unit-Based Compensation Beginning in 2022, the Company granted restricted stock units ("RSUs") to certain employees and other service providers subject to certain service-based or service- and performance-based vesting conditions. The ultimate number of shares that are issued in respect of the performance-based RSUs are based on actual performance over a three or four-year performance period and ranging from zero to 100% of the performance-based RSUs subject to the award. Each fiscal year within the award period represents a separately vesting tranche of the award. For a portion of the performance-based RSUs, as the performance conditions have not been established beyond the first year of the award, a grant date has not yet been established for the remaining annual periods of these performance-based RSUs. The performance-based RSUs are measured at fair value on their grant date. The related compensation expense for the performance awards is recognized on a straight line basis over the requisite service period for each separately vesting tranche of the award if and when the Company concludes that it is probable that the performance conditions will be achieved. At the end of each reporting period, the Company reevaluates the probability that the performance conditions will be achieved. Beginning in 2022, the Company granted stock options to certain employees, which generally vest as one-third (1/3) of the underlying shares based on continued service over four years , with 25 % of the time-based option shares vesting each year, and as to two-thirds (2/3) of the underlying shares subject to market-based vesting conditions over four years , with 25 % of the market-based option shares vesting each year subject to attainment of specified performance thresholds. Options generally expire ten years from the date of grant. The exercise price for each stock option award is equal to the closing price of a share of the Company's common stock on the grant date of the award. For stock option awards issued with only time-based vesting conditions, the fair value is estimated on the date of grant using a Black-Scholes option-pricing model, which requires inputs based on certain subjective assumptions, including the expected stock price volatility, the expected term of the option, the risk-free interest rate for a period that approximates the expected term of the option, and the Company's expected dividend yield. For stock option awards issued with time- and market-based vesting conditions, the grant date fair value is determined through the use of a Monte Carlo simulation that incorporates into the valuation the possibility that the market condition may not be satisfied. A Monte Carlo simulation requires the use of various assumptions, including the underlying stock price, volatility and the risk-free interest rate as of the valuation date, corresponding to the length of the time remaining in the performance period, and expected dividend yield. The expected term represents the derived service period for the respective tranches, which is the longer of the specified service period or the period in which the market conditions are expected to be met. Emerging Growth Company Status The Company is an emerging growth company, as defined in the Jumpstart Our Business Startups Act of 2012 (the "JOBS Act"). Under the JOBS Act, emerging growth companies can delay adopting new or revised accounting standards issued subsequent to the enactment of the JOBS Act until such time as those standards apply to private companies. The Company has elected to use this extended transition period for complying with new or revised accounting standards that have different effective dates for public and private companies until the earlier of the date that the Company (i) is no longer an emerging growth company or (ii) affirmatively and irrevocably opts out of the extended transition period provided in the JOBS Act. As a result, the Company's unaudited consolidated financial statements may not be comparable to companies that comply with the new or revised accounting pronouncements as of public company effective dates. New Accounting Pronouncements Not Yet Adopted In February 2016, the FASB issued ASU 2016-02, Leases (Topic 842) and also issued subsequent amendments to the initial guidance: ASU 2017-13, ASU 2018-10, ASU 2018-11, ASU 2018-20, ASU 2019-01, ASU 2020-02, and ASU 2020-05 (collectively, “ASC 842”). ASC 842 outlines a comprehensive lease accounting model and supersedes the current lease guidance. The new guidance requires lessees to recognize lease liabilities and corresponding right-of-use assets for all leases with lease terms of greater than 12 months. It also changes the definition of a lease and expands the disclosure requirements of lease arrangements. ASC 842 is effective for private entities for fiscal years beginning after December 15, 2021, and interim periods within fiscal years beginning after December 15, 2022, inclusive of a one year deferral provided by ASU 2020-05. ASC 842 must be adopted using a modified retrospective method and early adoption is permitted. The Company is in the process of determining the impact of the adoption of ASC 842 on the Company’s consolidated financial statements and disclosures. The Company has organized an implementation group to ensure the completeness of its lease information, analyze the appropriate classification of leases under the new standard, implement a leasing software system and develop new processes to execute, approve and classify leases on an ongoing basis. However, given the Company’s current operating lease portfolio (see Note 13 and Note 14) the Company expects the recognition of the right-of-use assets and lease liabilities to have a material impact on the Company’s consolidated balance sheets. In June 2016, the FASB issued ASU 2016-13, Financial Instruments (Topic 326)-Measurement of Credit Losses on Financial Instruments (“ASU 2016-13”). ASU 2016-13 requires an entity to utilize a new impairment model known as the current expected credit loss (“CECL”) model to estimate its lifetime “expected credit loss” and record an allowance that, when deducted from the amortized cost basis of the financial asset, presents the net amount expected to be collected on the financial asset. The CECL model is expected to result in more timely recognition of credit losses. ASU 2016-13 also requires new disclosures for financial assets measured at amortized cost, loans and available-for-sale debt securities. ASU 2016-13 is effective for private entities for fiscal years beginning after December 15, 2022, including interim periods within those fiscal years. ASU 2016-03 will apply as a cumulative-effect adjustment to retained earnings as of the beginning of the first reporting period in which the guidance is adopted. The Company is in the process of evaluating the impact of the adoption of ASU 2016-13 on the Company’s consolidated financial statements and disclosures. In December 2019, the FASB issued ASU 2019-12, Simplifying the Accounting for Income Taxes (“ASU 2019-12”). ASU 2019-12 simplifies the accounting for income taxes by removing certain exceptions to the general principles in Topic 740. The amendments also improve consistent application of and simplify GAAP for other areas of Topic 740 by clarifying and amending existing guidance. ASU 2019-12 is effective for private entities for fiscal years beginning after December 15, 2021, and interim periods within fiscal years beginning after December 15, 2022. Early adoption of the amendments is permitted, including adoption in any interim period for public business entities for periods for which financial statements have not yet been issued and all other entities for periods for which financial statements have not yet been made available for issuance. The Company is in the process of evaluating the impact of the adoption of ASU 2019-12 on the Company’s consolidated financial statements and disclosures.

Acquisitions

Acquisitions	9 Months Ended
	Sep. 30, 2022
Business Combinations [Abstract]
Acquisitions	NOTE 3 ACQUISITIONS During the three and nine months ended September 30, 2022 and 2021, the Company completed the acquisitions of 3 , 6 , 9 and 17 outpatient mental health practices, respectively. The Company accounted for the acquisitions as business combinations using the acquisition method of accounting. The purchase price was allocated to the tangible and intangible assets acquired and liabilities assumed based on their estimated fair values as of the respective acquisition dates. Total consideration transferred for these acquisitions consisted of the following: Three Months Ended September 30, Nine Months Ended September 30, 2022 2021 2022 2021 Cash consideration $ 5,099 $ 21,108 $ 41,024 $ 62,420 Cash consideration to be paid 251 — 251 325 Contingent consideration, at initial fair value 2,036 2,775 7,719 5,514 Class A-2 common units — — — 1,486 Total consideration transferred $ 7,386 $ 23,883 $ 48,994 $ 69,745 The results of the acquired businesses have been included in the Company’s consolidated financial statements beginning as of their acquisition dates. It is impracticable to provide historical supplemental pro forma financial information along with revenue and earnings subsequent to the acquisition dates for acquisitions during the period due to a variety of factors, including access to historical information and the operations of acquirees being integrated within the Company shortly after closing and not operating as discrete entities within the Company’s organizational structure. Fair Values of Assets Acquired and Liabilities Assumed The following table summarizes the preliminary fair values of assets acquired and liabilities assumed as of the dates of acquisition: Three Months Ended September 30, Nine Months Ended September 30, Allocation of Purchase Price 2022 2021 2022 2021 Cash $ 173 $ 820 $ 1,024 $ 2,868 Patient accounts receivable 649 963 1,842 4,762 Property and equipment 26 89 79 783 Prepaid expenses and other current assets 351 86 581 313 Other noncurrent assets 10 73 66 164 Intangible assets 589 1,260 2,272 4,321 Goodwill 6,394 22,198 45,621 63,485 Total assets acquired 8,192 25,489 51,485 76,696 Total liabilities assumed 806 1,606 2,491 6,951 Fair value of net assets $ 7,386 $ 23,883 $ 48,994 $ 69,745 The fair value of assets and liabilities other than intangible assets approximate the carrying amounts as of acquisition dates. The following table summarizes the fair values of acquired intangible assets as of the dates of acquisition: Three Months Ended September 30, Nine Months Ended September 30, 2022 2021 2022 2021 Regional trade names (1) $ 362 $ 775 $ 1,259 $ 2,691 Non-competition agreements (2) 227 485 1,013 1,630 Total $ 589 $ 1,260 $ 2,272 $ 4,321 (1) Useful lives for regional trade names are 5 years . (2) Useful lives for non-competition agreements are 5 years . Contingent Consideration Under the provisions of the acquisition agreements, the Company may pay additional cash consideration in the form of earnouts, contingent upon the acquirees achieving certain performance and operational targets (see Note 6). The following table summarizes the maximum contingent consideration based on the acquisition agreements: Three Months Ended September 30, Nine Months Ended September 30, Contingent consideration 2022 2021 2022 2021 Maximum contingent consideration based on $ 3,950 $ 3,400 $ 11,150 $ 6,750 Goodwill Goodwill represents the excess of the purchase price over the net identifiable assets acquired and liabilities assumed. Goodwill is primarily attributable to the assembled workforce, customer and payor relationships and anticipated synergies and economies of scale expected from the integration of the businesses. The synergies include certain cost savings, operating efficiencies, and other strategic benefits projected to be achieved as a result of the acquisition. Goodwill deductible for tax purposes is $ 42,485 from the acquisitions in 2022.

Intangible Assets

Intangible Assets	9 Months Ended
	Sep. 30, 2022
Goodwill and Intangible Assets Disclosure [Abstract]
Intangible Assets	NOTE 4 INTANGIBLE ASSETS Intangible assets consist of the following: September 30, 2022 Gross Accumulated Net Weighted Regional trade names $ 35,676 $ ( 14,884 ) $ 20,792 5.0 LifeStance trade names 235,500 ( 24,941 ) 210,559 22.5 Non-competition agreements 93,763 ( 52,641 ) 41,122 4.2 Total intangible assets $ 364,939 $ ( 92,466 ) $ 272,473 December 31, 2021 Gross Accumulated Net Weighted Regional trade names $ 34,417 $ ( 9,633 ) $ 24,784 5.0 LifeStance trade names 235,500 ( 17,090 ) 218,410 22.5 Non-competition agreements 92,750 ( 35,589 ) 57,161 4.2 Total intangible assets $ 362,667 $ ( 62,312 ) $ 300,355 Gross carrying amount is based on the fair value of the intangible assets determined at acquisitions. Total intangible asset amortization expense consists of the following: Three Months Ended September 30, Nine Months Ended September 30, 2022 2021 2022 2021 Amortization expense $ 10,204 $ 9,812 $ 30,154 $ 29,135

Property and Equipment, Net

Property and Equipment, Net	9 Months Ended
	Sep. 30, 2022
Property, Plant and Equipment [Abstract]
Property and Equipment, Net	NOTE 5 PROPERTY AND EQUIPMENT, NET Property and equipment, net consists of the following: September 30, 2022 December 31, 2021 Leasehold improvements $ 146,563 $ 87,807 Computers and peripherals 28,605 22,038 Furniture, fixtures and equipment 35,714 20,286 Medical equipment 951 1,018 Construction in process 20,987 40,619 Total $ 232,820 $ 171,768 Less: Accumulated depreciation ( 39,427 ) ( 19,526 ) Total property and equipment, net $ 193,393 $ 152,242 Depreciation expense consists of the following: Three Months Ended September 30, Nine Months Ended September 30, 2022 2021 2022 2021 Depreciation expense $ 7,680 $ 3,965 $ 20,157 $ 9,644

Fair Value Measurements

Fair Value Measurements	9 Months Ended
	Sep. 30, 2022
Fair Value Disclosures [Abstract]
Fair Value Measurements	NOTE 6 FAIR VALUE MEASUREMENTS Contingent Consideration The Company measures its contingent consideration liability at fair value on a recurring basis using Level 3 inputs. The Company estimates the fair value of the contingent consideration liability based on the likelihood and timing of the contingent earn-out payments. The following is the summary of the significant assumptions used for the fair value measurement of the contingent consideration liability as of September 30, 2022 and December 31, 2021. Valuation Technique Range of Significant Assumptions September 30, 2022 December 31, 2021 Probability-weighted analysis Probability 0 % - 100 % 50 % - 100 % based earn-outs Discount rate 6.00 % 8.60 % As of September 30, 2022 and December 31, 2021, the Company adjusted the fair value of the contingent consideration liability due to remeasurement at the reporting date. See Note 14 for discussion of payment of contingent consideration made related to acquisitions, fair value adjustments, and a roll-forward of the contingent consideration balance from the prior year. As disclosed in Note 3, the Company acquired several outpatient mental health practices during the three and nine months ended September 30, 2022 and 2021 . The values of net tangible assets acquired, and the resulting goodwill and other intangible assets, were recorded at fair value. The majority of the tangible assets acquired and liabilities assumed were recorded at their carrying values as of the respective dates of acquisition, as their carrying values approximated their fair values due to their short-term nature. The fair values of goodwill and other intangible assets acquired in these acquisitions were estimated by management or with the assistance of a third-party valuation expert primarily based on the income approach. The income approach estimates fair value based on the present value of the cash flows that the assets are expected to generate in the future. The Company developed estimates for the expected future cash flows and discount rates used in the present value calculations. Other than assets acquired and liabilities assumed in these acquisitions, there were no material assets or liabilities measured at fair value on a nonrecurring basis during the periods presented. Hedging Activities The Company uses derivative financial instruments, including an interest rate swap, for hedging and non-trading purposes to manage its exposure to changes in interest rates. The Company entered into a hedge transaction (interest rate swap) using a derivative financial instrument for the purpose of hedging the Company’s exposure to interest rate risks, which the contractual terms of the hedged instrument closely mirror those of the hedged item, providing a high degree of risk reduction and correlation. The objective of entering into the interest rate swap is to eliminate the variability of cash flows in the Secured Overnight Financing Rate ("SOFR") interest payments associated with variable-rate loan over the life of the loan. In August 2022, the Company entered into an interest rate swap agreement to pay a fixed rate of 3.24 % on a total notional value of $ 189,000 of debt. As a result of the interest rate swap, 94.5 % of the term loan previously exposed to interest rate risk from changes in SOFR is now hedged against the interest rate swap at a fixed rate. The interest rate swap matures on September 30, 2025. As of September 30, 2022, the notional value was $ 189,000 . As changes in interest rates impact the future cash flow of interest payments, the hedge provides a synthetic offset to interest rate movements. The Company used the income approach to value the derivative for the interest rate swap using observable market data for all significant inputs and standard valuation techniques to convert future amounts to a single present value amount, assuming that participants are motivated but not compelled to transact. This derivative instrument (interest rate swap) is designated and qualifies as a cash flow hedge, with the entire gain or loss on the derivative reported as a component of other comprehensive income. Amounts recorded in accumulated other comprehensive income are released to earnings in the same period that the hedged transaction impacts consolidated earnings within interest expense. The cash flows from the derivative treated as a cash flow hedge is classified in the Company’s consolidated statements of cash flows in the same category as the item being hedged. The following table summarizes the location of the interest rate swap in the consolidated balance sheets as of September 30, 2022: Consolidated balance sheets location September 30, 2022 Interest rate swap Other noncurrent assets $ 4,311 The amount of estimated cash flow hedge unrealized gains and losses that are expected to be reclassified to earnings in the next twelve months is not material. Fair Value Measured on a Recurring Basis The following table presents information about the Company’s assets and liabilities that are measured at fair value on a recurring basis: September 30, 2022 Level 1 Level 2 Level 3 Total Financial Instrument Interest rate swap asset $ — $ 4,311 $ — $ 4,311 Contingent consideration liability $ — $ — $ 12,297 $ 12,297 December 31, 2021 Level 1 Level 2 Level 3 Total Financial Instrument Contingent consideration liability $ — $ — $ 17,430 $ 17,430

Goodwill

Goodwill	9 Months Ended
	Sep. 30, 2022
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill	NOTE 7 GOODWILL Goodwill consists of the following: Amount Balance as of December 31, 2021 $ 1,204,544 Business acquisitions (Note 3) 45,621 Measurement period adjustments ( 372 ) Balance as of September 30, 2022 $ 1,249,793

Long-Term Debt

Long-Term Debt	9 Months Ended
	Sep. 30, 2022
Debt Disclosure [Abstract]
Long-term Debt	NOTE 8 LONG-TERM DEBT On May 14, 2020, in connection with the TPG Acquisition, the Company entered into the Credit Agreement among LifeStance Health Holdings, Inc., Lynnwood Intermediate Holdings, Inc., Capital One, National Association, and each lender party thereto (the “May 2020 Credit Agreement”). The term loans and delayed draw loans were payable in quarterly principal and interest payments through May 14, 2026 . On May 4, 2022, the Company entered into a credit agreement (the “2022 Credit Agreement”) among LifeStance Health Holdings, Inc., Lynnwood Intermediate Holdings, Inc., Capital One, National Association, and each lender party thereto. The 2022 Credit Agreement established commitments in respect of a term loan facility of $ 200,000 , a revolving loan facility of up to $ 50,000 and a delayed draw term loan facility of up to $ 100,000 . The commitments under the term loan facility and the revolving facility were available to be drawn on May 16, 2022. The Company borrowed $ 200,000 in term loans on that date, with a maturity date of May 16, 2028 . On June 29, 2022, the Company drew $ 11,000 from the revolving loan and on July 5, 2022, the Company converted the outstanding balance on the revolving loan to a delayed draw term loan with a maturity date of May 16, 2028. The remaining commitments under the delayed draw term loan facility are scheduled to terminate on the second anniversary of May 16, 2022 . The loans under the term loan facility and the delayed draw term loan facility bear interest at a rate per annum equal to (x) adjusted term SOFR (which adjusted term SOFR is subject to a minimum of 0.75 %) plus an applicable margin of 4.50 % or (y) an alternate base rate (which will be the highest of (i) the prime rate, (ii) 0.50 % above the federal funds effective rate and (iii) one-month adjusted term SOFR (which adjusted term SOFR is subject to a minimum of 0.75 %) plus 1.00 %) plus an applicable margin of 3.50 %. The term loans are collateralized by substantially all of the assets of the Company. The revolving loan has interest only payments until the maturity date of May 16, 2027 . The proceeds from the 2022 Credit Agreement term loans were used to repay in full and extinguish the May 2020 Credit Agreement. The 2022 Credit Agreement term loans are treated as a new issuance of debt. In relation to the May 2020 Credit Agreement, the Company recognized an extinguishment of debt charge within interest expense of $ 3,380 , consisting of $ 1,609 prepayment charge and the write-off of unamortized debt issue costs associated with the extinguished term loans of $ 1,771 . In September 2022, the Company drew $ 3,500 from the aforementioned delayed draw term loan commitment. The 2022 Credit Agreement requires the Company to maintain compliance with certain restrictive financial covenants related to earnings, leverage ratios, and other financial metrics. The Company was in compliance with all debt covenants at September 30, 2022 and December 31, 2021. Long-term debt consists of the following: September 30, 2022 December 31, 2021 Term loans $ 200,000 $ 70,665 Delayed Draw loans 14,500 90,565 Revolving loan 6,000 — Total long-term debt 220,500 161,230 Less: Current portion of long-term debt ( 2,145 ) ( 1,323 ) Less: Unamortized discount and debt issue costs (1) ( 6,313 ) ( 2,491 ) Total Long-Term Debt, Net of Current Portion $ 212,042 $ 157,416 (1) The unamortized debt issue costs related to long-term debt are presented as a reduction of the carrying amount of the corresponding liabilities on the unaudited consolidated balance sheets. Unamortized debt issue costs related to delayed draw term loan commitments and revolving loans are presented within other noncurrent assets on the unaudited consolidated balance sheets. The current portion of long-term debt is included within other current liabilities on the unaudited consolidated balance sheets. Interest expense consists of the following: Three Months Ended September 30, Nine Months Ended September 30, 2022 2021 2022 2021 Interest expense $ 4,189 $ 3,503 $ 14,763 $ 35,309 Future principal payments on long-term debt are as follows: Year Ended December 31, Amount Remainder of 2022 $ 536 2023 2,145 2024 2,145 2025 2,145 2026 2,145 Thereafter 211,384 Total $ 220,500 The fair value of long-term debt is based on the present value of future payments discounted by the market interest rates or the fixed rates based on current rates offered to the Company for debt with similar terms and maturities, which is a Level 2 fair value measurement. Long-term debt is presented at carrying value on the unaudited consolidated balance sheets. The fair value of long-term debt at September 30, 2022 and December 31, 2021 was $ 210,426 and $ 186,497 , respectively. Revolving Loan Under the May 2020 Credit Agreement, the Company had a revolving loan commitment from Capital One in the amount of $ 20,000 . Under the 2022 Credit Agreement, the Company has a revolving loan commitment from Capital One in the amount of $ 50,000 . Any borrowing on the revolving loan under the 2022 Credit Agreement is due in full on May 16, 2027 . The revolving loan bears interest at a rate per annum equal to (x) adjusted term SOFR plus an applicable margin of 3.25 % or (y) an alternate base rate (which will be the highest of (i) the prime rate, (ii) 0.50 % above the federal funds effective rate and (iii) one-month adjusted term SOFR plus 1.00 %) plus an applicable margin of 2.25 %. The unused revolving loan incurs a commitment fee of 0.50 % per annum. In September 2022, the Company drew $ 6,000 from the aforementioned revolving loan under the 2022 Credit Agreement.

Total Revenue

Total Revenue	9 Months Ended
	Sep. 30, 2022
Revenues [Abstract]
Total Revenue	NOTE 9 TOTAL REVENUE The Company’s total revenue is dependent on a series of contracts with third-party payors, which is typical for providers in the health care industry. The Company has determined that the nature, amount, timing and uncertainty of revenue and cash flows are affected by the payor mix with third-party payors, which have different reimbursement rates. The payor mix of fee-for-service revenue from patients and third-party payors consists of the following: Three Months Ended September 30, Nine Months Ended September 30, 2022 2021 2022 2021 Amount % of Total Revenue Amount % of Total Revenue Amount % of Total Revenue Amount % of Total Revenue Commercial $ 196,013 91 % $ 158,035 91 % $ 568,683 91 % $ 433,684 91 % Government 9,648 4 % 8,731 5 % 27,544 4 % 20,942 4 % Self-pay 9,489 4 % 5,948 3 % 26,587 4 % 19,230 4 % Total patient service 215,150 99 % 172,714 99 % 622,814 99 % 473,856 99 % Nonpatient service 2,410 1 % 1,121 1 % 7,368 1 % 3,660 1 % Total $ 217,560 100 % $ 173,835 100 % $ 630,182 100 % $ 477,516 100 % Among the commercial payors, the table below represents insurance companies that individually represented 10 % or more of revenue: Three Months Ended September 30, Nine Months Ended September 30, 2022 2021 2022 2021 Top one payor 19 % 19 % 19 % 19 % Top two payor 14 % 18 % 14 % 17 % Top three payor — 12 % — 13 %

Income Taxes

Income Taxes	9 Months Ended
	Sep. 30, 2022
Income Tax Disclosure [Abstract]
Income Taxes	NOTE 10 INCOME TAXES The benefit for income taxes is as follows: Three Months Ended September 30, Nine Months Ended September 30, 2022 2021 2022 2021 Benefit for income taxes $ 4,353 $ 8,751 $ 10,106 $ 15,300 The effective tax rates are as follows: Three Months Ended September 30, Nine Months Ended September 30, 2022 2021 2022 2021 Effective tax rate 10.3 % 6.8 % 5.6 % 7.1 % The difference between the Company’s effective tax rate and the U.S. statutory tax rate of 21 % was prima rily the result of non-deductible equity awards. The Company regularly evaluates the realizability of its deferred tax assets and establishes a valuation allowance if it is more likely than not that some or all the deferred tax assets will not be realized. The Company had a valuation allowance of $ 239 and $ 0 as of September 30, 2022 and December 31, 2021 , respectively.

Stock And Unit-Based Compensati

Stock And Unit-Based Compensation	9 Months Ended
	Sep. 30, 2022
Share-Based Payment Arrangement [Abstract]
Stock and Unit - Based Compensation	NOTE 11 STOCK AND UNIT-BASED COMPENSATION 2021 Equity Incentive Plan Effective June 9, 2021, the Company’s Board of Directors (the "Board") and its stockholders as of that date adopted and approved the LifeStance Health Group, Inc. 2021 Equity Incentive Plan (the “2021 Equity Incentive Plan”). All equity-based awards subsequent to June 9, 2021 will be granted under the 2021 Plan. The 2021 Equity Incentive Plan permits the grant of awards or restricted or unrestricted common stock, stock options, stock appreciation rights, restricted stock units, performance awards, and other stock-based awards to employees and directors of, and consultants and advisors to, the Company and its affiliates. The maximum number of shares of the Company’s common stock that may be delivered in satisfaction of awards under the 2021 Equity Incentive Plan was initially reserved at 47,037 shares. The share pool will automatically increase on January 1 of each year through and including 2031 by the lesser of (i) five percent of the number of shares of the Company’s common stock outstanding as of the close of business on the immediately preceding December 31 and (ii) the number of shares determined by the Board on or prior to such date for such year. On January 1, 2022, the number of shares of common stock reserved and available for issuance under the 2021 Equity Incentive Plan increased by 18,713 shares. Restricted Stock The RSAs were issued as part of the Organizational Transactions (see Note 1). The following is a summary of RSA transactions as of and for the nine months ended September 30, 2022: Unvested Shares Weighted-Average Unvested, December 31, 2021 23,501 $ 11.98 Vested ( 5,916 ) 11.98 Forfeited ( 213 ) 11.98 Unvested, September 30, 2022 17,372 $ 11.98 Restricted Stock Units The RSUs were granted in connection with the IPO and subsequent to the IPO. RSUs are accounted for as equity using the fair value method, which requires measurement and recognition of compensation expense for all awards granted to employees, directors and consultants based upon the grant-date fair value. The following is a summary of RSU transactions as of and for the nine months ended September 30, 2022: Unvested Shares Weighted-Average Outstanding, December 31, 2021 6,031 $ 17.95 Granted 11,826 8.53 Vested ( 2,000 ) 17.53 Canceled and forfeited ( 1,413 ) 8.53 Outstanding, September 30, 2022 14,444 $ 10.66 Stock Options The following is a summary of stock option activity as of and for the nine months ended September 30, 2022: Number of Options Weighted-Average Weighted-Average Aggregate Intrinsic Value Outstanding, December 31, 2021 — $ — — $ — Granted 12,226 7.61 Exercised — — Forfeited — — Outstanding, September 30, 2022 12,226 $ 7.61 9.94 $ — Vested or expected to vest at 12,226 $ 7.61 9.94 $ — The total grant-date fair value of stock options granted during the nine months ended September 30, 2022 was $ 52,979 . The Company estimated the fair value of stock option grants with time-based vesting conditions using a Black-Scholes option-pricing model with the following assumptions presented on a weighted-average basis: Nine Months Ended Risk-free interest rate 3.22 % Volatility 55.00 % Expected term (years) 6.25 Expected dividend yield 0.00 % Estimated fair value $ 4.24 The Company estimated the fair value of stock option grants with time- and market-based vesting conditions using a Monte Carlo simulation that incorporate estimates of the potential outcomes of the market condition on the grant with the following assumptions: Nine Months Ended Risk-free interest rate 3.22 % Volatility 55.00 % Expected service period (years) 2.76 Expected dividend yield 0.00 % Weighted-average fair value per option granted $ 4.38 Stock and Unit-Based Compensation Expense The Company recognized stock and unit-based compensation expense related to RSAs, RSUs, stock options, and the Class B Profits Interests within general and administrative expenses in the unaudited consolidated statements of operations and comprehensive loss as follows: Three Months Ended September 30, Nine Months Ended September 30, 2022 2021 2022 2021 Stock and unit-based compensation expense $ 34,870 $ 120,689 $ 152,235 $ 150,809 As of September 30, 2022, the Company had $ 200,893 in unrecognized compensation expense related to all non-vested awards (RSAs, RSUs and stock options) that will be recognized over the weighted-average remaining service period of 1.9 years. 2021 Employee Stock Purchase Plan Effective June 9, 2021, the Board and its stockholders as of that date adopted and approved the LifeStance Health Group, Inc. 2021 Employee Stock Purchase Plan (the “ESPP”). The ESPP permits the grant to eligible employees of the Company and its participating subsidiaries of options to purchase shares of the Company’s common stock. The aggregate number of shares of the Company common stock initially available for purchase pursuant to the exercise of options under the ESPP was 6,817 shares, plus an automatic annual increase, as of January 1 of each year beginning in 2022 and continuing through and including 2031, equal to the lesser of (i) one percent of the number of shares of the Company’s common stock outstanding as of the close of business on the immediately preceding December 31 and (ii) the number of shares determined by the Board on or prior to such date for such year, up to a maximum of 42,500 shares of the Company’s common stock in the aggregate. On January 1, 2022, the number of shares of common stock reserved and available for issuance under the ESPP increased by 3,743 shares. The ESPP allows participants to purchase common stock through payroll deductions of up to 15 % of their eligible compensation. The purchase price of the shares will be 85 % of the lower of the fair market value of the Company’s common stock on the grant date or the exercise date. The ESPP will generally be implemented by a series of separate offerings referred to as “Option Periods”. Unless otherwise determined by the administrator, the Option Periods will be successive periods of approximately six months commencing on the first business day in January and July of each year, anticipated to be on or around January 1 and July 1, and ending approximately six months later on the last business day in June or December, as applicable, of each year, anticipated to be on or around June 30 and December 31. The last business day of each Option Period will be an “Exercise Date”. The administrator may change the Exercise Date, the commencement date, the ending date and the duration of each Option Period, in each case, to the extent permitted by Section 423 of the Internal Revenue Code; provided, however, that no option may be exercised after 27 months from its grant date. As of September 30, 2022 , no shares of common stock have been purchased under the Company’s ESPP.

Stockholders' Equity Members' D

Stockholders' Equity Members' Deficit	9 Months Ended
	Sep. 30, 2022
Stockholders' Equity Note [Abstract]
Stockholders'/Member' Equity	NOTE 12 STOCKHOLDERS’/MEMBERS’ EQUITY Common Stock – Post-IPO As discussed in Note 1, upon completion of the Company’s IPO in June 2021, the Company sold 32,800 shares of common stock at an offering price of $ 18.00 per share. In connection with the IPO, the Company increased its authorized shares from 1 to 800,000 shares of common stock, par value $ 0.01 per share. Common Units - Pre-IPO The former chief executive officer (“Former CEO”) had 35,000 redeemable Class A units outstanding prior to the completion of the IPO. The Former CEO had the right, upon termination for any reason other than proper cause, to put his redeemable Class A units back to the partnership at fair value (“Put Right”). The Former CEO (or permitted transferee) shall have this Put Right also upon death or disability. As this was both outside of the Company’s control and probable to eventually occur, the redeemable Class A units subject to this Put Right were classified as mezzanine equity and carried at fair value (i.e., redemption price). There was a change to the fair value during the nine months ended September 30, 2021 of $ 36,750 resulting from a change in the probability assumption of an IPO. On June 9, 2021, the redeemable Class A units were converted into 10,234 shares of the Company’s common stock. Class A-1 Common Units had equal voting rights. Class A-2 and Class B Common Units were nonvoting units. Preferred Stock In connection with the Company’s IPO, the Company authorized the issuance of 25,000 shares of its preferred stock, par value $ 0.01 per share. There are no shares of preferred stock outstanding as of September 30, 2022 and December 31, 2021 .

Related Party Transactions

Related Party Transactions	9 Months Ended
	Sep. 30, 2022
Related Party Transactions [Abstract]
Related Party Transactions	NOTE 13 RELATED PARTY TRANSACTIONS The Company leases 19 office facilities under operating leases with related parties expiring through 2030 . The leases provide for monthly minimum rent payments, and some include renewal options for additional terms. Minimum rent payments under operating leases are recognized on a straight-line basis over the term of the lease. Total related-party rent expense included in center costs, excluding depreciation and amortization in the unaudited consolidated statements of operations and comprehensive loss amounted to: Three Months Ended September 30, Nine Months Ended September 30, 2022 2021 2022 2021 Rent expense $ 397 $ 809 $ 1,175 $ 2,006 A summary of non-cancelable future minimum operating lease payments under these leases as of September 30, 2022 is as follows: Year Ended December 31, Amount Remainder of 2022 $ 421 2023 1,604 2024 1,489 2025 1,513 2026 539 Thereafter 503 Total $ 6,069 In addition, management fees to TPG and certain executives of the Company were identified as related party transactions. For the nine months ended September 30, 2021, the Company incurred related-party management fees of $ 1,445 . As a result of the Company’s IPO, the Company terminated its management services agreement in the second quarter of 2021, and no management fees were recognized subsequent to the IPO. As part of the 2022 Credit Agreement restructuring, TPG provided arrangement and structuring services. The Company incurred related party fees of $ 4,375 during the nine months ended September 30, 2022 included within debt issue costs.

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2022
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	NOTE 14 COMMITMENTS AND CONTINGENCIES Contingent Consideration relating to Acquisitions For the nine months ended September 30, 2022, there were post-closing payments contingent upon the future performance of the Company’s recently acquired targets achieving certain agreed-upon performance metrics. Contingent consideration is recorded at fair value and was recognized in the purchase price allocation (see Note 3) of the acquired company. The following table presents changes to the Company’s contingent consideration balance: September 30, 2022 December 31, 2021 Beginning balance $ 17,430 $ 16,414 Additions related to acquisitions 7,719 10,685 Payments of contingent consideration ( 12,290 ) ( 12,279 ) (Gain) loss on remeasurement ( 562 ) 2,610 Ending balance $ 12,297 $ 17,430 Leases with Third Parties The Company leases its office facilities under operating leases expiring through 2032 . The leases provide for monthly minimum rent payments, and some include renewal options for additional terms. Minimum rent payments under operating leases are recognized on a straight-line basis over the term of the lease. Total third-party rent expense amounted to as follows in the unaudited consolidated statements of operations and comprehensive loss: Three Months Ended September 30, Nine Months Ended September 30, 2022 2021 2022 2021 Center costs, excluding depreciation and amortization $ 13,421 $ 8,302 $ 36,439 $ 21,878 General and administrative expenses 405 127 683 655 Total rent expense $ 13,826 $ 8,429 $ 37,122 $ 22,533 A summary of non-cancellable future minimum third-party operating lease payments under these leases as of September 30, 2022 is as follows: Year Ended December 31, Amount Remainder of 2022 $ 14,449 2023 59,245 2024 56,750 2025 53,070 2026 46,583 Thereafter 68,862 Total $ 298,959 Professional Liability Insurance The medical malpractice insurance coverage is subject to a $ 3,000 per claim limit and an annual aggregate shared limit of $ 8,000 . Should the claims-made policy not be renewed or replaced with equivalent insurance, claims based on occurrences during its term, but reported subsequently, would be uninsured. The Company is not aware of any unasserted claims, unreported incidents, or claims outstanding that are expected to exceed malpractice insurance coverage limits as of September 30, 2022 and December 31, 2021. Health Care Industry The health care industry is subject to numerous laws and regulations of federal, state, and local governments. These laws and regulations include, but are not necessarily limited to, matters such as licensure, accreditation, and government health care program participation requirements, reimbursement for patient services, and Medicare fraud and abuse. Recently, government activity has increased with respect to investigations and allegations concerning possible violations of fraud and abuse statutes and regulations by health care providers. Violation of these laws and regulations could result in expulsion from government health care programs together with imposition of significant fines and penalties, as well as significant repayments for patient services billed. Laws and regulations concerning government programs, including Medicare and Medicaid, are complex and subject to varying interpretation. As a result of investigations by governmental agencies, various health care companies have received requests for information and notices regarding alleged noncompliance with those laws and regulations, which, in some instances, have resulted in companies entering into significant settlement agreements. Compliance with such laws and regulations may also be subject to future government review and interpretation as well as significant regulatory action, including fines, penalties, and potential exclusion from the related programs. There can be no assurance that regulatory authorities will not challenge the Company’s compliance with these laws and regulations, and it is not possible to determine the impact (if any) such claims or penalties would have upon the Company. In addition, the contracts the Company has with commercial payors also provide for retroactive audit and review of claims. Management believes that the Company is in substantial compliance with fraud and abuse as well as other applicable government laws and regulations. While no regulatory inquiries have been made, compliance with such laws and regulations is subject to government review and interpretation, as well as regulatory actions unknown or unasserted at this time. General Contingencies The Company is exposed to various risks of loss related to torts; theft of, damage to and destruction of assets; errors and omissions, injuries to employees, and natural disasters. These risks are covered by commercial insurance purchased from independent third parties. There has been no significant reduction in insurance coverage from the previous year in any of the Company’s policies. Litigation The Company may be involved from time-to-time in legal actions relating to the ownership and operations of its business. In management’s opinion, the liabilities, if any, that may ultimately result from such legal actions are not expected to have a material adverse effect on the financial condition, results of operations, or cash flows of the Company. In March 2020, the Company received a Civil Investigative Demand from the U.S. Attorney’s Office of the Northern District of Georgia involving an investigation of a laboratory arrangement. The Company does not believe that it is a target of the investigation or that there is any material exposure based on its internal review. The Company does not know how the investigation will be resolved, to what extent it may be expanded, or whether the Company or its employees will be subject to further investigation, enforcement action or related penalties that could have an adverse impact on its business, results of operations and financial condition. On August 10, 2022, a shareholder class action lawsuit captioned Nayani v. LifeStance Health Group, Inc., et al. was filed in the United States District Court for the Southern District of New York (the “Court”) against the Company and certain executives and board members (the “LifeStance Defendants”), as well as the underwriters of the Company’s initial public offering (the “IPO”) (collectively, “Defendants”). The lawsuit alleges, in part, that the Defendants violated Section 11 of the Securities Act of 1933 (the “Securities Act”) because the IPO registration statement purportedly contained inaccurate and misleading statements and/or failed to disclose certain facts concerning patient visits and clinician retention. The lawsuit also asserts that the LifeStance Defendants violated Section 15 of the Securities Act because they are control persons of the Company. The lawsuit seeks unspecified monetary damages and purports to represent all shareholders who purchased the Company’s common stock pursuant to the IPO registration statement. Under the Private Securities Litigation Reform Act, applications to become lead plaintiff and lead counsel were due by October 11, 2022. The process to select a lead plaintiff is ongoing. The process of resolving these matters is inherently uncertain and may develop over an extended period of time; therefore, at this time, the ultimate resolution cannot be predicted. The Company has not recorded any material accruals for loss contingencies and in management's opinion no material range of loss is estimable for this matter as of September 30, 2022.

Net Loss Per Share

Net Loss Per Share	9 Months Ended
	Sep. 30, 2022
Earnings Per Share [Abstract]
Net Loss Per Share	NOTE 15 NET LOSS PER SHARE Prior to the IPO, as discussed in Note 1, the partnership interests of LifeStance TopCo included Redeemable Class A, Class A common and Class B units. The Class B Units were intended to be "profits interests" for U.S. federal income tax purposes. Prior to the IPO, each of the holders of partnership interests in LifeStance TopCo contributed its partnership interest to LifeStance Health Group in exchange for shares of common stock (including shares of common stock issued as RSAs subject to vesting) of LifeStance Health Group, with no changes in relative equity holder rights, rank or value before or after this exchange. As a result, the LifeStance TopCo equity exchange of common units was considered equivalent to a stock split and requires retrospective treatment for net loss per share purposes. All share and per share information has been retroactively adjusted to reflect the equity exchange for all periods presented. Vested Class B Profits Interests Units outstanding prior to the equity exchange were considered compensatory arrangements that were settled with shares of common stock at the time of the exchange and have been included as outstanding shares subsequent to that date. The following table presents the calculation of basic and diluted net loss per share (“EPS”) for the Company’s common shares (on an as-converted basis): Three Months Ended September 30, Nine Months Ended September 30, 2022 2021 2022 2021 Net loss available to common stockholders'/members' $ ( 37,853 ) $ ( 120,452 ) $ ( 168,908 ) $ ( 235,917 ) Weighted-average shares used to compute basic and 357,520 343,394 354,057 321,283 Net loss per share, basic and diluted $ ( 0.11 ) $ ( 0.35 ) $ ( 0.48 ) $ ( 0.73 ) The Company has issued potentially dilutive instruments in the form of RSAs, RSUs and stock options. The Company did not include any of these instruments in its calculation of diluted loss per share (on an as-converted basis) for the three and nine months ended September 30, 2022 and 2021 because to include them would be anti-dilutive due to the Company’s net loss during the period. See Note 11 for the issued, vested and unvested RSAs, RSUs and stock options. The Company excluded the following potential common shares, presented based on amounts outstanding at each period end, from the computation of diluted net loss per share: As of September 30, 2022 2021 RSAs 17,372 30,749 RSUs 14,444 6,208 Stock options 12,226 — 44,042 36,957

Subsequent Events

Subsequent Events	9 Months Ended
	Sep. 30, 2022
Subsequent Events [Abstract]
Subsequent Events	NOTE 16 SUBSEQUENT EVENTS Acquisitions Subsequent to September 30, 2022, the Company completed acquisitions of several outpatient mental health practices. The allocation of purchase price, including any fair value of contingent consideration, to the assets acquired and liabilities assumed as of the acquisition dates have not been completed. For acquisitions completed subsequent to September 30, 2022, total contractual consideration included cash consideration of $ 18,740 , funded through credit facility financing, and contingent consideration with a maximum value of $ 2,475 .

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2022
Accounting Policies [Abstract]
Basis of Presentation and Principles of Consolidation	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 Health Group, LifeStance TopCo, its wholly-owned subsidiaries and VIEs in which LifeStance TopCo 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, 2021 in the Company's Annual Report on Form 10-K. On May 14, 2020, affiliates of TPG acquired the majority of the equity interests of LifeStance Health Holdings, Inc. through certain newly formed subsidiaries ("TPG Acquisition"). Periods subsequent to the acquisition and prior to the IPO and restructuring transactions reflect the financial statements of LifeStance TopCo. Periods subsequent to the IPO and restructuring transactions reflect the financial statements of LifeStance Health Group. All periods subsequent to the TPG Acquisition have been presented as the financial statements of LifeStance Health Group.
Use of Accounting Estimates	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.
Variable Interest Entities	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 a 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 September 30, 2022 and December 31, 2021 .
Stock and Unit-Based Compensation	Stock and Unit-Based Compensation Beginning in 2022, the Company granted restricted stock units ("RSUs") to certain employees and other service providers subject to certain service-based or service- and performance-based vesting conditions. The ultimate number of shares that are issued in respect of the performance-based RSUs are based on actual performance over a three or four-year performance period and ranging from zero to 100% of the performance-based RSUs subject to the award. Each fiscal year within the award period represents a separately vesting tranche of the award. For a portion of the performance-based RSUs, as the performance conditions have not been established beyond the first year of the award, a grant date has not yet been established for the remaining annual periods of these performance-based RSUs. The performance-based RSUs are measured at fair value on their grant date. The related compensation expense for the performance awards is recognized on a straight line basis over the requisite service period for each separately vesting tranche of the award if and when the Company concludes that it is probable that the performance conditions will be achieved. At the end of each reporting period, the Company reevaluates the probability that the performance conditions will be achieved. Beginning in 2022, the Company granted stock options to certain employees, which generally vest as one-third (1/3) of the underlying shares based on continued service over four years , with 25 % of the time-based option shares vesting each year, and as to two-thirds (2/3) of the underlying shares subject to market-based vesting conditions over four years , with 25 % of the market-based option shares vesting each year subject to attainment of specified performance thresholds. Options generally expire ten years from the date of grant. The exercise price for each stock option award is equal to the closing price of a share of the Company's common stock on the grant date of the award. For stock option awards issued with only time-based vesting conditions, the fair value is estimated on the date of grant using a Black-Scholes option-pricing model, which requires inputs based on certain subjective assumptions, including the expected stock price volatility, the expected term of the option, the risk-free interest rate for a period that approximates the expected term of the option, and the Company's expected dividend yield. For stock option awards issued with time- and market-based vesting conditions, the grant date fair value is determined through the use of a Monte Carlo simulation that incorporates into the valuation the possibility that the market condition may not be satisfied. A Monte Carlo simulation requires the use of various assumptions, including the underlying stock price, volatility and the risk-free interest rate as of the valuation date, corresponding to the length of the time remaining in the performance period, and expected dividend yield. The expected term represents the derived service period for the respective tranches, which is the longer of the specified service period or the period in which the market conditions are expected to be met.
Emerging Growth Company Status	Emerging Growth Company Status The Company is an emerging growth company, as defined in the Jumpstart Our Business Startups Act of 2012 (the "JOBS Act"). Under the JOBS Act, emerging growth companies can delay adopting new or revised accounting standards issued subsequent to the enactment of the JOBS Act until such time as those standards apply to private companies. The Company has elected to use this extended transition period for complying with new or revised accounting standards that have different effective dates for public and private companies until the earlier of the date that the Company (i) is no longer an emerging growth company or (ii) affirmatively and irrevocably opts out of the extended transition period provided in the JOBS Act. As a result, the Company's unaudited consolidated financial statements may not be comparable to companies that comply with the new or revised accounting pronouncements as of public company effective dates.
New Accounting Pronouncements Not Yet Adopted	New Accounting Pronouncements Not Yet Adopted In February 2016, the FASB issued ASU 2016-02, Leases (Topic 842) and also issued subsequent amendments to the initial guidance: ASU 2017-13, ASU 2018-10, ASU 2018-11, ASU 2018-20, ASU 2019-01, ASU 2020-02, and ASU 2020-05 (collectively, “ASC 842”). ASC 842 outlines a comprehensive lease accounting model and supersedes the current lease guidance. The new guidance requires lessees to recognize lease liabilities and corresponding right-of-use assets for all leases with lease terms of greater than 12 months. It also changes the definition of a lease and expands the disclosure requirements of lease arrangements. ASC 842 is effective for private entities for fiscal years beginning after December 15, 2021, and interim periods within fiscal years beginning after December 15, 2022, inclusive of a one year deferral provided by ASU 2020-05. ASC 842 must be adopted using a modified retrospective method and early adoption is permitted. The Company is in the process of determining the impact of the adoption of ASC 842 on the Company’s consolidated financial statements and disclosures. The Company has organized an implementation group to ensure the completeness of its lease information, analyze the appropriate classification of leases under the new standard, implement a leasing software system and develop new processes to execute, approve and classify leases on an ongoing basis. However, given the Company’s current operating lease portfolio (see Note 13 and Note 14) the Company expects the recognition of the right-of-use assets and lease liabilities to have a material impact on the Company’s consolidated balance sheets. In June 2016, the FASB issued ASU 2016-13, Financial Instruments (Topic 326)-Measurement of Credit Losses on Financial Instruments (“ASU 2016-13”). ASU 2016-13 requires an entity to utilize a new impairment model known as the current expected credit loss (“CECL”) model to estimate its lifetime “expected credit loss” and record an allowance that, when deducted from the amortized cost basis of the financial asset, presents the net amount expected to be collected on the financial asset. The CECL model is expected to result in more timely recognition of credit losses. ASU 2016-13 also requires new disclosures for financial assets measured at amortized cost, loans and available-for-sale debt securities. ASU 2016-13 is effective for private entities for fiscal years beginning after December 15, 2022, including interim periods within those fiscal years. ASU 2016-03 will apply as a cumulative-effect adjustment to retained earnings as of the beginning of the first reporting period in which the guidance is adopted. The Company is in the process of evaluating the impact of the adoption of ASU 2016-13 on the Company’s consolidated financial statements and disclosures. In December 2019, the FASB issued ASU 2019-12, Simplifying the Accounting for Income Taxes (“ASU 2019-12”). ASU 2019-12 simplifies the accounting for income taxes by removing certain exceptions to the general principles in Topic 740. The amendments also improve consistent application of and simplify GAAP for other areas of Topic 740 by clarifying and amending existing guidance. ASU 2019-12 is effective for private entities for fiscal years beginning after December 15, 2021, and interim periods within fiscal years beginning after December 15, 2022. Early adoption of the amendments is permitted, including adoption in any interim period for public business entities for periods for which financial statements have not yet been issued and all other entities for periods for which financial statements have not yet been made available for issuance. The Company is in the process of evaluating the impact of the adoption of ASU 2019-12 on the Company’s consolidated financial statements and disclosures.

Acquisitions (Tables)

Acquisitions (Tables)	9 Months Ended
	Sep. 30, 2022
Business Combinations [Abstract]
Summary Of Consideration Transferred	Total consideration transferred for these acquisitions consisted of the following: Three Months Ended September 30, Nine Months Ended September 30, 2022 2021 2022 2021 Cash consideration $ 5,099 $ 21,108 $ 41,024 $ 62,420 Cash consideration to be paid 251 — 251 325 Contingent consideration, at initial fair value 2,036 2,775 7,719 5,514 Class A-2 common units — — — 1,486 Total consideration transferred $ 7,386 $ 23,883 $ 48,994 $ 69,745
Schedule of Recognized Assets Acquired and Liabilities Assumed	The following table summarizes the preliminary fair values of assets acquired and liabilities assumed as of the dates of acquisition: Three Months Ended September 30, Nine Months Ended September 30, Allocation of Purchase Price 2022 2021 2022 2021 Cash $ 173 $ 820 $ 1,024 $ 2,868 Patient accounts receivable 649 963 1,842 4,762 Property and equipment 26 89 79 783 Prepaid expenses and other current assets 351 86 581 313 Other noncurrent assets 10 73 66 164 Intangible assets 589 1,260 2,272 4,321 Goodwill 6,394 22,198 45,621 63,485 Total assets acquired 8,192 25,489 51,485 76,696 Total liabilities assumed 806 1,606 2,491 6,951 Fair value of net assets $ 7,386 $ 23,883 $ 48,994 $ 69,745 The fair value of assets and liabilities other than intangible assets approximate the carrying amounts as of acquisition dates.
Schedule of Fair Values of Acquired Intangible Assets	The following table summarizes the fair values of acquired intangible assets as of the dates of acquisition: Three Months Ended September 30, Nine Months Ended September 30, 2022 2021 2022 2021 Regional trade names (1) $ 362 $ 775 $ 1,259 $ 2,691 Non-competition agreements (2) 227 485 1,013 1,630 Total $ 589 $ 1,260 $ 2,272 $ 4,321 (1) Useful lives for regional trade names are 5 years . (2) Useful lives for non-competition agreements are 5 years .
Schedule of Maximum Contingent Consideration Based on the Acquisition Agreements	The following table summarizes the maximum contingent consideration based on the acquisition agreements: Three Months Ended September 30, Nine Months Ended September 30, Contingent consideration 2022 2021 2022 2021 Maximum contingent consideration based on $ 3,950 $ 3,400 $ 11,150 $ 6,750

Intangible Assets (Tables)

Intangible Assets (Tables)	9 Months Ended
	Sep. 30, 2022
Goodwill and Intangible Assets Disclosure [Abstract]
Summary of Intangible Assets	Intangible assets consist of the following: September 30, 2022 Gross Accumulated Net Weighted Regional trade names $ 35,676 $ ( 14,884 ) $ 20,792 5.0 LifeStance trade names 235,500 ( 24,941 ) 210,559 22.5 Non-competition agreements 93,763 ( 52,641 ) 41,122 4.2 Total intangible assets $ 364,939 $ ( 92,466 ) $ 272,473 December 31, 2021 Gross Accumulated Net Weighted Regional trade names $ 34,417 $ ( 9,633 ) $ 24,784 5.0 LifeStance trade names 235,500 ( 17,090 ) 218,410 22.5 Non-competition agreements 92,750 ( 35,589 ) 57,161 4.2 Total intangible assets $ 362,667 $ ( 62,312 ) $ 300,355
Summary of Intangible Assets Amortization Expense	Gross carrying amount is based on the fair value of the intangible assets determined at acquisitions. Total intangible asset amortization expense consists of the following: Three Months Ended September 30, Nine Months Ended September 30, 2022 2021 2022 2021 Amortization expense $ 10,204 $ 9,812 $ 30,154 $ 29,135

Property and Equipment, Net (Ta

Property and Equipment, Net (Tables)	9 Months Ended
	Sep. 30, 2022
Property, Plant and Equipment [Abstract]
Schedule of Property and Equipment	Property and equipment, net consists of the following: September 30, 2022 December 31, 2021 Leasehold improvements $ 146,563 $ 87,807 Computers and peripherals 28,605 22,038 Furniture, fixtures and equipment 35,714 20,286 Medical equipment 951 1,018 Construction in process 20,987 40,619 Total $ 232,820 $ 171,768 Less: Accumulated depreciation ( 39,427 ) ( 19,526 ) Total property and equipment, net $ 193,393 $ 152,242
Schedule of Depreciation Expense	Depreciation expense consists of the following: Three Months Ended September 30, Nine Months Ended September 30, 2022 2021 2022 2021 Depreciation expense $ 7,680 $ 3,965 $ 20,157 $ 9,644

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2022
Fair Value Disclosures [Abstract]
Summary of the Significant Assumptions Used for the Fair Value Measurement of the Contingent Consideration Liability	The following is the summary of the significant assumptions used for the fair value measurement of the contingent consideration liability as of September 30, 2022 and December 31, 2021. Valuation Technique Range of Significant Assumptions September 30, 2022 December 31, 2021 Probability-weighted analysis Probability 0 % - 100 % 50 % - 100 % based earn-outs Discount rate 6.00 % 8.60 %
Schedule of Location of the Interest Rate Swap	The following table summarizes the location of the interest rate swap in the consolidated balance sheets as of September 30, 2022: Consolidated balance sheets location September 30, 2022 Interest rate swap Other noncurrent assets $ 4,311
Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis	The following table presents information about the Company’s assets and liabilities that are measured at fair value on a recurring basis: September 30, 2022 Level 1 Level 2 Level 3 Total Financial Instrument Interest rate swap asset $ — $ 4,311 $ — $ 4,311 Contingent consideration liability $ — $ — $ 12,297 $ 12,297 December 31, 2021 Level 1 Level 2 Level 3 Total Financial Instrument Contingent consideration liability $ — $ — $ 17,430 $ 17,430

Goodwill (Tables)

Goodwill (Tables)	9 Months Ended
	Sep. 30, 2022
Goodwill and Intangible Assets Disclosure [Abstract]
Summary of Goodwill	Goodwill consists of the following: Amount Balance as of December 31, 2021 $ 1,204,544 Business acquisitions (Note 3) 45,621 Measurement period adjustments ( 372 ) Balance as of September 30, 2022 $ 1,249,793

Long- Term Debt (Tables)

Long- Term Debt (Tables)	9 Months Ended
	Sep. 30, 2022
Debt Disclosure [Abstract]
Summary of Long-term Debt Instruments	Long-term debt consists of the following: September 30, 2022 December 31, 2021 Term loans $ 200,000 $ 70,665 Delayed Draw loans 14,500 90,565 Revolving loan 6,000 — Total long-term debt 220,500 161,230 Less: Current portion of long-term debt ( 2,145 ) ( 1,323 ) Less: Unamortized discount and debt issue costs (1) ( 6,313 ) ( 2,491 ) Total Long-Term Debt, Net of Current Portion $ 212,042 $ 157,416 (1) The unamortized debt issue costs related to long-term debt are presented as a reduction of the carrying amount of the corresponding liabilities on the unaudited consolidated balance sheets. Unamortized debt issue costs related to delayed draw term loan commitments and revolving loans are presented within other noncurrent assets on the unaudited consolidated balance sheets.
Summary of Interest Expense	Interest expense consists of the following: Three Months Ended September 30, Nine Months Ended September 30, 2022 2021 2022 2021 Interest expense $ 4,189 $ 3,503 $ 14,763 $ 35,309
Summary of Maturities of Long-term Debt	Future principal payments on long-term debt are as follows: Year Ended December 31, Amount Remainder of 2022 $ 536 2023 2,145 2024 2,145 2025 2,145 2026 2,145 Thereafter 211,384 Total $ 220,500

Total Revenue (Tables)

Total Revenue (Tables)	9 Months Ended
	Sep. 30, 2022
Disaggregation of Revenue [Abstract]
Schedule of revenue from patients and third - party payors	The payor mix of fee-for-service revenue from patients and third-party payors consists of the following: Three Months Ended September 30, Nine Months Ended September 30, 2022 2021 2022 2021 Amount % of Total Revenue Amount % of Total Revenue Amount % of Total Revenue Amount % of Total Revenue Commercial $ 196,013 91 % $ 158,035 91 % $ 568,683 91 % $ 433,684 91 % Government 9,648 4 % 8,731 5 % 27,544 4 % 20,942 4 % Self-pay 9,489 4 % 5,948 3 % 26,587 4 % 19,230 4 % Total patient service 215,150 99 % 172,714 99 % 622,814 99 % 473,856 99 % Nonpatient service 2,410 1 % 1,121 1 % 7,368 1 % 3,660 1 % Total $ 217,560 100 % $ 173,835 100 % $ 630,182 100 % $ 477,516 100 %
Schedule of percentage of revenue from insurance companies	Among the commercial payors, the table below represents insurance companies that individually represented 10 % or more of revenue: Three Months Ended September 30, Nine Months Ended September 30, 2022 2021 2022 2021 Top one payor 19 % 19 % 19 % 19 % Top two payor 14 % 18 % 14 % 17 % Top three payor — 12 % — 13 %

Income Taxes (Tables)

Income Taxes (Tables)	9 Months Ended
	Sep. 30, 2022
Income Tax Disclosure [Abstract]
Schedule of Provision for Income Tax Expense (Benefit)	The benefit for income taxes is as follows: Three Months Ended September 30, Nine Months Ended September 30, 2022 2021 2022 2021 Benefit for income taxes $ 4,353 $ 8,751 $ 10,106 $ 15,300
Schedule of Effective Tax Rates	The effective tax rates are as follows: Three Months Ended September 30, Nine Months Ended September 30, 2022 2021 2022 2021 Effective tax rate 10.3 % 6.8 % 5.6 % 7.1 %

Stock And Unit-Based Compensa_2

Stock And Unit-Based Compensation (Tables)	9 Months Ended
	Sep. 30, 2022
Share-Based Payment Arrangement [Abstract]
Summary of Restricted Stock Awards (RSA) Activity	The following is a summary of RSA transactions as of and for the nine months ended September 30, 2022: Unvested Shares Weighted-Average Unvested, December 31, 2021 23,501 $ 11.98 Vested ( 5,916 ) 11.98 Forfeited ( 213 ) 11.98 Unvested, September 30, 2022 17,372 $ 11.98
Summary of Restricted Stock Unit (RSU) Activity	The following is a summary of RSU transactions as of and for the nine months ended September 30, 2022: Unvested Shares Weighted-Average Outstanding, December 31, 2021 6,031 $ 17.95 Granted 11,826 8.53 Vested ( 2,000 ) 17.53 Canceled and forfeited ( 1,413 ) 8.53 Outstanding, September 30, 2022 14,444 $ 10.66
Summary of Stock Option Activity	The following is a summary of stock option activity as of and for the nine months ended September 30, 2022: Number of Options Weighted-Average Weighted-Average Aggregate Intrinsic Value Outstanding, December 31, 2021 — $ — — $ — Granted 12,226 7.61 Exercised — — Forfeited — — Outstanding, September 30, 2022 12,226 $ 7.61 9.94 $ — Vested or expected to vest at 12,226 $ 7.61 9.94 $ —
Schedule of Stock Opions Assumptions	The Company estimated the fair value of stock option grants with time-based vesting conditions using a Black-Scholes option-pricing model with the following assumptions presented on a weighted-average basis: Nine Months Ended Risk-free interest rate 3.22 % Volatility 55.00 % Expected term (years) 6.25 Expected dividend yield 0.00 % Estimated fair value $ 4.24 The Company estimated the fair value of stock option grants with time- and market-based vesting conditions using a Monte Carlo simulation that incorporate estimates of the potential outcomes of the market condition on the grant with the following assumptions: Nine Months Ended Risk-free interest rate 3.22 % Volatility 55.00 % Expected service period (years) 2.76 Expected dividend yield 0.00 % Weighted-average fair value per option granted $ 4.38
Summary of Unit Based Compensation Expense	The Company recognized stock and unit-based compensation expense related to RSAs, RSUs, stock options, and the Class B Profits Interests within general and administrative expenses in the unaudited consolidated statements of operations and comprehensive loss as follows: Three Months Ended September 30, Nine Months Ended September 30, 2022 2021 2022 2021 Stock and unit-based compensation expense $ 34,870 $ 120,689 $ 152,235 $ 150,809

Related Party Transactions (Tab

Related Party Transactions (Tables)	9 Months Ended
	Sep. 30, 2022
Related Party Transactions [Abstract]
Schedule Of Related-party Rent Expense	Total related-party rent expense included in center costs, excluding depreciation and amortization in the unaudited consolidated statements of operations and comprehensive loss amounted to: Three Months Ended September 30, Nine Months Ended September 30, 2022 2021 2022 2021 Rent expense $ 397 $ 809 $ 1,175 $ 2,006
Schedule Of Future Minimum Rental Payments For Operating Leases Table	A summary of non-cancelable future minimum operating lease payments under these leases as of September 30, 2022 is as follows: Year Ended December 31, Amount Remainder of 2022 $ 421 2023 1,604 2024 1,489 2025 1,513 2026 539 Thereafter 503 Total $ 6,069

Commitments and Contingencies (

Commitments and Contingencies (Tables)	9 Months Ended
	Sep. 30, 2022
Business Acquisition, Contingent Consideration [Line Items]
Schedule of Maximum Contingent Consideration Based on the Acquisition Agreements	The following table summarizes the maximum contingent consideration based on the acquisition agreements: Three Months Ended September 30, Nine Months Ended September 30, Contingent consideration 2022 2021 2022 2021 Maximum contingent consideration based on $ 3,950 $ 3,400 $ 11,150 $ 6,750
Schedule Of Related-party Rent Expense	Total related-party rent expense included in center costs, excluding depreciation and amortization in the unaudited consolidated statements of operations and comprehensive loss amounted to: Three Months Ended September 30, Nine Months Ended September 30, 2022 2021 2022 2021 Rent expense $ 397 $ 809 $ 1,175 $ 2,006
Contingent Consideration [Member]
Business Acquisition, Contingent Consideration [Line Items]
Schedule of Maximum Contingent Consideration Based on the Acquisition Agreements	The following table presents changes to the Company’s contingent consideration balance: September 30, 2022 December 31, 2021 Beginning balance $ 17,430 $ 16,414 Additions related to acquisitions 7,719 10,685 Payments of contingent consideration ( 12,290 ) ( 12,279 ) (Gain) loss on remeasurement ( 562 ) 2,610 Ending balance $ 12,297 $ 17,430
Schedule Of Related-party Rent Expense	Total third-party rent expense amounted to as follows in the unaudited consolidated statements of operations and comprehensive loss: Three Months Ended September 30, Nine Months Ended September 30, 2022 2021 2022 2021 Center costs, excluding depreciation and amortization $ 13,421 $ 8,302 $ 36,439 $ 21,878 General and administrative expenses 405 127 683 655 Total rent expense $ 13,826 $ 8,429 $ 37,122 $ 22,533
Summary of Future Minimum Lease Payments	A summary of non-cancellable future minimum third-party operating lease payments under these leases as of September 30, 2022 is as follows: Year Ended December 31, Amount Remainder of 2022 $ 14,449 2023 59,245 2024 56,750 2025 53,070 2026 46,583 Thereafter 68,862 Total $ 298,959

Net Loss Per Share (Tables)

Net Loss Per Share (Tables)	9 Months Ended
	Sep. 30, 2022
Earnings Per Share [Abstract]
Schedule of Basic and Diluted Net Loss Per Share	The following table presents the calculation of basic and diluted net loss per share (“EPS”) for the Company’s common shares (on an as-converted basis): Three Months Ended September 30, Nine Months Ended September 30, 2022 2021 2022 2021 Net loss available to common stockholders'/members' $ ( 37,853 ) $ ( 120,452 ) $ ( 168,908 ) $ ( 235,917 ) Weighted-average shares used to compute basic and 357,520 343,394 354,057 321,283 Net loss per share, basic and diluted $ ( 0.11 ) $ ( 0.35 ) $ ( 0.48 ) $ ( 0.73 )
Computation of Diluted Net Loss per Share	The Company excluded the following potential common shares, presented based on amounts outstanding at each period end, from the computation of diluted net loss per share: As of September 30, 2022 2021 RSAs 17,372 30,749 RSUs 14,444 6,208 Stock options 12,226 — 44,042 36,957

Nature of the Business - Additi

Nature of the Business - Additional Information (Details) - USD ($) $ / shares in Units, $ in Thousands			9 Months Ended
	Jun. 25, 2021	Jun. 14, 2021	Sep. 30, 2022	Sep. 30, 2021
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Organisation incorporated date			Jan. 28, 2021
Proceeds from initial public offering, net of underwriters discounts and commissions and deferred offering costs			$ 0	$ 548,905
Life Stance Health Foundation [Member]
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Issuance of common , Shares			500,000
Cash payment for restructuring			$ 1,000
Aggregate cost			$ 10,000
LifeStance TopCo
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Number of units converted			1,046,196,000
LifeStance [Member]
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Proceeds from initial public offering, net of underwriters discounts and commissions and deferred offering costs		$ 548,905
Payments for underwriting expense		32,472
Deferred offering costs		$ 9,023
Conversion of common units into common stock upon closing of initial public offering, Shares			310,083,000
Common Stock Subject To Service-Based Vesting [Member]
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Conversion of common units into common stock upon closing of initial public offering, Shares			30,766,000
Common Stock [Member]
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Conversion of common units into common stock upon closing of initial public offering, Shares				295,663
Class B Profits Interests Units [Member]
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Number of units converted			152,620
Selling Shareholders [Member] | Common Stock [Member]
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Issuance of common , Shares		7,200,000
Shares offering, price per share		$ 18
IPO [Member]
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Shares offering, price per share			$ 18
IPO [Member] | LifeStance [Member]
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Issuance of common , Shares		32,800,000
IPO [Member] | Common Stock [Member]
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Issuance of common , Shares				32,800
Over-Allotment Option
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Issuance of common , Shares	6,000,000

Summary of Significant Accoun_3

Summary of Significant Accounting Policies - Additional Information (Details)	9 Months Ended
	Sep. 30, 2022
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Acquisition of Non Medical Assets	100%
Expiration Period	10 years
Performance Shares [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Vesting Period	4 years
Percentage of option shares	25%
Time Based Option [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Vesting Period	4 years
Percentage of option shares	25%

Acquisitions - Additional Infor

Acquisitions - Additional Information (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022 USD ($) Facility	Sep. 30, 2021 Facility	Sep. 30, 2022 USD ($) Facility	Sep. 30, 2021 Facility
Business Combinations [Abstract]
Acquisitions of outpatient mental health practices | Facility	3	6	9	17
Goodwill deductible for tax purposes | $	$ 42,485		$ 42,485

Acquisitions - Summary of Consi

Acquisitions - Summary of Consideration Transferred (Details) - Outpatient Mental Health Practices - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Business Acquisition [Line Items]
Cash consideration	$ 5,099	$ 21,108	$ 41,024	$ 62,420
Cash consideration to be paid	251	0	251	325
Total consideration transferred	7,386	23,883	48,994	69,745
Debt [Member]
Business Acquisition [Line Items]
Class A-2 common units	0	0	0	1,486
Class A-2 Common Units [Member]
Business Acquisition [Line Items]
Contingent consideration, at initial fair value	$ 2,036	$ 2,775	$ 7,719	$ 5,514

Acquisitions - Schedule of Fair

Acquisitions - Schedule of Fair Value Assets Acquired And Liabilities Assumed (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Business Combinations [Abstract]
Cash	$ 173	$ 820	$ 1,024	$ 2,868
Patient accounts receivable	649	963	1,842	4,762
Property and equipment	26	89	79	783
Prepaid expenses and other current assets	351	86	581	313
Other noncurrent assets	10	73	66	164
Intangible assets	589	1,260	2,272	4,321
Goodwill	6,394	22,198	45,621	63,485
Total assets acquired	8,192	25,489	51,485	76,696
Total liabilities assumed	806	1,606	2,491	6,951
Fair value of net assets	$ 7,386	$ 23,883	$ 48,994	$ 69,745

Acquisitions - Schedule of Fa_2

Acquisitions - Schedule of Fair Values of Acquired Intangible Assets (Details) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Business Acquisition [Line Items]
Acquired intangible assets, Fair value		$ 589	$ 1,260	$ 2,272	$ 4,321
Regional Trade Names [Member]
Business Acquisition [Line Items]
Acquired intangible assets, Fair value	[1]	362	775	1,259	2,691
Non-Competition Agreements [Member]
Business Acquisition [Line Items]
Acquired intangible assets, Fair value	[2]	$ 227	$ 485	$ 1,013	$ 1,630
[1] Useful lives for regional trade names are 5 years . Useful lives for non-competition agreements are 5 years .

Acquisitions - Schedule of Fa_3

Acquisitions - Schedule of Fair Values of Acquired Intangible Assets (Parenthetical) (Details)	9 Months Ended
	Sep. 30, 2022
Regional Trade Names [Member]
Business Acquisition [Line Items]
Useful lives for acquired intangible assets	5 years
Non-Competition Agreements [Member]
Business Acquisition [Line Items]
Useful lives for acquired intangible assets	5 years

Acquisitions - Schedule of Maxi

Acquisitions - Schedule of Maximum Contingent Consideration Based on the Acquisition Agreements (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Contingent Consideration [Member]
Business Acquisition [Line Items]
Maximum contingent consideration based on acquisition agreements	$ 3,950	$ 3,400	$ 11,150	$ 6,750

Intangible Assets - Summary of

Intangible Assets - Summary of Intangible Assets (Details) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2022	Dec. 31, 2021
Finite Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 364,939	$ 362,667
Accumulated Amortization	(92,466)	(62,312)
Net Carrying Amount	272,473	300,355
Regional Trade Names [Member]
Finite Lived Intangible Assets [Line Items]
Gross Carrying Amount	35,676	34,417
Accumulated Amortization	(14,884)	(9,633)
Net Carrying Amount	$ 20,792	$ 24,784
Intangible assets useful life	5 years	5 years
Life Stance Trade Names [Member]
Finite Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 235,500	$ 235,500
Accumulated Amortization	(24,941)	(17,090)
Net Carrying Amount	$ 210,559	$ 218,410
Intangible assets useful life	22 years 6 months	22 years 6 months
Non-Competition Agreements [Member]
Finite Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 93,763	$ 92,750
Accumulated Amortization	(52,641)	(35,589)
Net Carrying Amount	$ 41,122	$ 57,161
Intangible assets useful life	4 years 2 months 12 days	4 years 2 months 12 days

Intangible Assets - Summary o_2

Intangible Assets - Summary of Intangible Asset Amortization Expense (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Goodwill and Intangible Assets Disclosure [Abstract]
Amortization expense	$ 10,204	$ 9,812	$ 30,154	$ 29,135

Property and Equipment, Net - S

Property and Equipment, Net - Schedule of Property and Equipment (Details) - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Property Plant And Equipment [Line Items]
Total	$ 232,820	$ 171,768
Less: Accumulated depreciation	(39,427)	(19,526)
Total property and equipment, net	193,393	152,242
Leasehold Improvements [Member]
Property Plant And Equipment [Line Items]
Total	146,563	87,807
Computers and Peripherals [Member]
Property Plant And Equipment [Line Items]
Total	28,605	22,038
Furniture, Fixtures and Equipment [Member]
Property Plant And Equipment [Line Items]
Total	35,714	20,286
Medical Equipment [Member]
Property Plant And Equipment [Line Items]
Total	951	1,018
Construction in Process [Member]
Property Plant And Equipment [Line Items]
Total	$ 20,987	$ 40,619

Property and Equipment, Net -_2

Property and Equipment, Net - Schedule of Depreciation Expense (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Property, Plant and Equipment [Abstract]
Depreciation expense	$ 7,680	$ 3,965	$ 20,157	$ 9,644

Fair Value Measurements - Summa

Fair Value Measurements - Summary of the Significant Assumptions Used for the Fair Value Measurement of the Contingent Consideration Liability (Details)	Sep. 30, 2022	Dec. 31, 2021
Minimum | Probability Weighted Analysis
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Business Combination, Contingent Consideration, Liability, Measurement Input	0	0.50
Minimum | F T E Based Earn Outs
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Business Combination, Contingent Consideration, Liability, Measurement Input	0.0600	0.0860
Maximum | Probability Weighted Analysis
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Business Combination, Contingent Consideration, Liability, Measurement Input	1	1

Fair Value Measurements - Sched

Fair Value Measurements - Schedule of location of the interest rate swap (Details) $ in Thousands	Sep. 30, 2022 USD ($)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Asset, Statement of Financial Position [Extensible Enumeration]	Other noncurrent assets
Interest Rate Swap Member
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Interest rate swap	$ 4,311

Fair Value Measurements - Sum_2

Fair Value Measurements - Summary of Fair Value, Assets and Liabilities Measured on Recurring Basis (Details) - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Contingent consideration liability	$ 12,297	$ 17,430
Interest Rate Swap Asset Member
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Interest rate swap asset	4,311
Fair Value, Inputs, Level 1
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Contingent consideration liability	0	0
Fair Value, Inputs, Level 1 | Interest Rate Swap Asset Member
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Interest rate swap asset	0
Fair Value, Inputs, Level 2
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Contingent consideration liability	0	0
Fair Value, Inputs, Level 2 | Interest Rate Swap Asset Member
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Interest rate swap asset	4,311
Fair Value, Inputs, Level 3
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Contingent consideration liability	12,297	$ 17,430
Fair Value, Inputs, Level 3 | Interest Rate Swap Asset Member
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Interest rate swap asset	$ 0

Fair Value Measurements - Addit

Fair Value Measurements - Additional Information (Details) - USD ($)	Sep. 30, 2022	Aug. 31, 2022
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Materail assets or liabilities measured at fair value on a recurring basis	$ 0
Interest Rate Swap Member | Secured Overnight Financing Rate (SOFR) Member
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt exposed to interest rate risk		94.50%
Interest Rate Swap Member | Cash Flow Hedging Member
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative fixed interest rate		3.24%
Notional amount	$ 189,000	$ 189,000

Goodwill - Schedule of Goodwill

Goodwill - Schedule of Goodwill (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2022 USD ($)
Goodwill [Line Items]
Beginning balance	$ 1,204,544
Business acquisitions	45,621
Measurement period adjustment	(372)
Ending balance	$ 1,249,793

Long-Term Debt - Summary of Lon

Long-Term Debt - Summary of Long-term Debt Instruments (Detail) - USD ($)		Sep. 30, 2022	May 04, 2022	Dec. 31, 2021
Debt Instrument [Line Items]
Term loans		$ 212,042,000		$ 157,416,000
Less: Current portion of long-term debt		(2,145,000)		(1,323,000)
Less: Unamortized discount and debt issue costs	[1]	(6,313,000)		(2,491,000)
Total		220,500,000		161,230,000
Term Loans
Debt Instrument [Line Items]
Total		200,000,000	$ 200,000	70,665,000
Delayed Drawn Loans
Debt Instrument [Line Items]
Total		14,500,000		90,565,000
Revolving Loan
Debt Instrument [Line Items]
Total		$ 6,000,000		$ 0
[1] The unamortized debt issue costs related to long-term debt are presented as a reduction of the carrying amount of the corresponding liabilities on the unaudited consolidated balance sheets. Unamortized debt issue costs related to delayed draw term loan commitments and revolving loans are presented within other noncurrent assets on the unaudited consolidated balance sheets.

Long-Term Debt - Additional Inf

Long-Term Debt - Additional Information (Detail) - USD ($)			9 Months Ended
	May 04, 2022	May 14, 2020	Sep. 30, 2022	Jun. 29, 2022	Dec. 31, 2021
Debt Instrument [Line Items]
Long-term Debt, Fair Value			$ 210,426,000		$ 186,497
Long-term Debt, Maturities, Repayment Terms	May 16, 2028	May 14, 2026
Long term debt fair value			220,500,000		161,230,000
Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Loan withdrawal amount				$ 11,000,000
Revolving loan outstanding amount				$ 11,000,000
May 2020 Credit Agreement [Member]
Debt Instrument [Line Items]
Extinguishment of Debt, Amount			3,380
Prepayment charge			1,609
Unamortized Debt Issuance Expense			1,771
May 2020 Credit Agreement [Member] | Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Maximum borrowing capacity			20,000
2022 Credit Agreement [Member]
Debt Instrument [Line Items]
Term loan facility	$ 200,000
Debt instrument, basis spread on variable rate	1%
2022 Credit Agreement [Member] | Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Loan withdrawal amount			6,000,000
Maximum borrowing capacity			$ 50,000
Unused revolving loan commitment fee percentage			0.0050
Revolving loan outstanding amount			$ 6,000,000
Revolving loan,expiration date			May 16, 2027
Term Loans
Debt Instrument [Line Items]
Long term debt fair value	$ 200,000		$ 200,000,000		70,665,000
Delayed Drawn Loans
Debt Instrument [Line Items]
Long term debt fair value			14,500,000		$ 90,565,000
Aggregate loan commitment amount			$ 3,500
Maximum | 2022 Credit Agreement [Member]
Debt Instrument [Line Items]
Loan withdrawal amount	50,000
Revolving loan outstanding amount	50,000
Maximum | Delayed Drawn Loans | 2022 Credit Agreement [Member]
Debt Instrument [Line Items]
Aggregate loan commitment amount	$ 100,000
Secured Overnight Financing Rate (SOFR) Member | 2022 Credit Agreement [Member]
Debt Instrument [Line Items]
Long-term Debt, Maturities, Repayment Terms	May 16, 2027
Secured Overnight Financing Rate (SOFR) Member | Minimum | May 2020 Credit Agreement [Member] | Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate			1%
Secured Overnight Financing Rate (SOFR) Member | Minimum | 2022 Credit Agreement [Member]
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate	0.75%
Secured Overnight Financing Rate (SOFR) Member | Maximum | May 2020 Credit Agreement [Member] | Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate			3.25%
Secured Overnight Financing Rate (SOFR) Member | Maximum | 2022 Credit Agreement [Member]
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate	4.50%
Federal Funds Rate | May 2020 Credit Agreement [Member] | Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate			0.50%
Federal Funds Rate | 2022 Credit Agreement [Member]
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate	0.50%
Base Rate
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate	3.50%
Base Rate | May 2020 Credit Agreement [Member] | Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate			2.25%

Long-Term Debt - Summary of Int

Long-Term Debt - Summary of Interest Expense (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Debt Disclosure [Abstract]
Interest expense	$ 4,189	$ 3,503	$ 14,763	$ 35,309

Long-Term Debt - Future Princip

Long-Term Debt - Future Principal Payments on Long Term Debt (Detail) - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Debt Disclosure [Abstract]
Remainder of 2022	$ 536
2023	2,145
2024	2,145
2025	2,145
2026	2,145
Thereafter	211,384
Total	$ 220,500	$ 161,230

Total Revenue - Additional Info

Total Revenue - Additional Information (Details)	Sep. 30, 2022
Minimum [Member]
Health Care Organization, Receivable and Revenue Disclosures [Line Items]
% of Total Revenue	10%

Total Revenue - Schedule of Rev

Total Revenue - Schedule of Revenue From Patients And Third - Party Payors (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Health Care Organization Receivable And Revenue Disclosures [Line Items]
Amount	$ 217,560	$ 173,835	$ 630,182	$ 477,516
% of Total Revenue	100%	100%	100%	100%
Commercial
Health Care Organization Receivable And Revenue Disclosures [Line Items]
Amount	$ 196,013	$ 158,035	$ 568,683	$ 433,684
% of Total Revenue	91%	91%	91%	91%
Government
Health Care Organization Receivable And Revenue Disclosures [Line Items]
Amount	$ 9,648	$ 8,731	$ 27,544	$ 20,942
% of Total Revenue	4%	5%	4%	4%
Self-pay
Health Care Organization Receivable And Revenue Disclosures [Line Items]
Amount	$ 9,489	$ 5,948	$ 26,587	$ 19,230
% of Total Revenue	4%	3%	4%	4%
Total patient service revenue
Health Care Organization Receivable And Revenue Disclosures [Line Items]
Amount	$ 215,150	$ 172,714	$ 622,814	$ 473,856
% of Total Revenue	99%	99%	99%	99%
Nonpatient service revenue
Health Care Organization Receivable And Revenue Disclosures [Line Items]
Amount	$ 2,410	$ 1,121	$ 7,368	$ 3,660
% of Total Revenue	1%	1%	1%	1%

Total Revenue - Schedule of Per

Total Revenue - Schedule of Percentage Of Revenue From Insurance Companies (Details)	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Health Care Organization Receivable And Revenue Disclosures [Line Items]
% of Total Revenue	100%	100%	100%	100%
Top one payor
Health Care Organization Receivable And Revenue Disclosures [Line Items]
% of Total Revenue	19%	19%	19%	19%
Top two payor
Health Care Organization Receivable And Revenue Disclosures [Line Items]
% of Total Revenue	14%	18%	14%	17%
Top three payor
Health Care Organization Receivable And Revenue Disclosures [Line Items]
% of Total Revenue	0%	12%	0%	13%

Income Taxes - Schedule of Prov

Income Taxes - Schedule of Provision for Income Tax Expense (Benefit) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Income Statement [Abstract]
Benefit for income taxes	$ 4,353	$ 8,751	$ 10,106	$ 15,300

Income Taxes - Schedule of Effe

Income Taxes - Schedule of Effective Tax Rates (Details)	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Income Statement [Abstract]
Effective tax rate	10.30%	6.80%	5.60%	7.10%

Income Taxes - Additional Infor

Income Taxes - Additional Information (Details) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2022	Dec. 31, 2021
Income Tax Disclosure [Abstract]
Statutory tax rate	21%
Effective tax rate due to its valuation allowance	$ 239	$ 0

Stock And Unit-Based Compensa_3

Stock And Unit-Based Compensation - Additional Information (Details)	1 Months Ended	9 Months Ended
	Aug. 31, 2021 shares	Sep. 30, 2022 USD ($) shares	Jan. 01, 2022 shares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Unrecognized compensation expense | $		$ 200,893
Unrecognized compensattion expense, weighted-average period		1 year 10 months 24 days
Grant-date fair value of stock options granted | $		$ 52,979,000
2021 Equity Incentive Plan [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Company's common stock		47,037
Share-based compensation arrangement by share-based payment award, description		The share pool will automatically increase on January 1 of each year through and including 2031 by the lesser of (i) five percent of the number of shares of the Company’s common stock outstanding as of the close of business on the immediately preceding December 31 and (ii) the number of shares determined by the Board on or prior to such date for such year.
Common Stock, Capital Shares Reserved for Future Issuance			18,713
2021 Employee Stock Purchase Plan [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share-based compensation arrangement by share-based payment award, description	January 1 of each year beginning in 2022 and continuing through and including 2031, equal to the lesser of (i) one percent of the number of shares of the Company’s common stock outstanding as of the close of business on the immediately preceding December 31 and (ii) the number of shares determined by the Board on or prior to such date for such year, up to a maximum of 42,500 shares of the Company’s common stock in the aggregate. On January 1, 2022, the number of shares of common stock reserved and available for issuance under the ESPP increased by 3,743 shares.
Common Stock, Capital Shares Reserved for Future Issuance			3,743
Exercise of stock options	6,817
Percentage of Purchase Price	85
2021 Employee Stock Purchase Plan [Member] | Common Stock [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock Issued During Period, Shares, Employee Stock Purchase Plans		0
2021 Employee Stock Purchase Plan [Member] | Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Company's common stock	42,500,000
Percentage of deduction on pay roll	15

Stock And Unit-Based Compensa_4

Stock And Unit-Based Compensation - Summary of Restricted Stock Awards (RSA) Activity (Details) - Restricted Stock Award	9 Months Ended
	Sep. 30, 2022 $ / shares shares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Outstanding | shares	23,501
Vested | shares	(5,916)
Forfeited | shares	(213)
Outstanding | shares	17,372
Outstanding | $ / shares	$ 11.98
Vested | $ / shares	11.98
Forfeited | $ / shares	11.98
Outstanding | $ / shares	$ 11.98

Stock And Unit-Based Compensa_5

Stock And Unit-Based Compensation - Summary of Restricted Stock Unit (RSU) Activity (Details) - Restricted Stock Unit	9 Months Ended
	Sep. 30, 2022 $ / shares shares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Outstanding | shares	6,031
Granted | shares	11,826
Vested | shares	(2,000)
Canceled and forfeited | shares	(1,413)
Outstanding | shares	14,444
Outstanding | $ / shares	$ 17.95
Granted | $ / shares	8.53
Vested | $ / shares	17.53
Forfeited | $ / shares	8.53
Outstanding | $ / shares	$ 10.66

Stock And Unit-Based Compensa_6

Stock And Unit-Based Compensation - Summary of Stock Option Activity (Details) - Stock Options [Member] $ / shares in Units, $ in Thousands	9 Months Ended
	Sep. 30, 2022 USD ($) $ / shares shares
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Number of shares options outstanding, Beginning Balance | shares	0
Number of options, granted | shares	12,226
Number of options, exercised | shares	0
Number of options, forfeited | shares	0
Number of shares options outstanding, Ending Balance | shares	12,226
Number of shares options, vested or expected to vest | shares	12,226
Weighted average exercise price outstanding, Beginning Balance | $ / shares	$ 0
Weighted average exercise price, granted | $ / shares	7.61
Weighted average exercise price, exercised | $ / shares	0
Weighted average exercise price, forfeited | $ / shares	0
Weighted average exercise price outstanding, Ending Balance | $ / shares	7.61
Weighted average exercise price, vested or expected to vest | $ / shares	$ 7.61
Weighted average remaining term in years, Outstanding, Ending	9 years 11 months 8 days
Weighted average remaining contractual life, vested or expected to vest	9 years 11 months 8 days
Aggregate intrinsic value, vested or expected | $	$ 0

Stock And Unit-Based Compensa_7

Stock And Unit-Based Compensation - Schedule of Stock Options Assumptions (Details)	9 Months Ended
	Sep. 30, 2022 $ / shares
Black-Scholes option-pricing model
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Risk-free interest rate	3.22%
Volatility	55%
Expected term (years)	6 years 3 months
Expected dividend yield	0%
Estimated fair value	$ 4.24
Monte Carlo Simulation
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Risk-free interest rate	3.22%
Volatility	55%
Expected term (years)	2 years 9 months 3 days
Expected dividend yield	0%
Estimated fair value	$ 4.38

Stock And Unit-Based Compensa_8

Stock And Unit-Based Compensation - Summary of Class B Profits Interests General and Administrative Expenses (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Class B Profits Interests Units [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock and unit-based compensation expense	$ 34,870	$ 120,689	$ 152,235	$ 150,809

Stockholders'_Members' Equity -

Stockholders'/Members' Equity - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands			9 Months Ended
	Jun. 14, 2021	Jun. 09, 2021	Sep. 30, 2021	Sep. 30, 2022	Dec. 31, 2021
Subsidiary Sale Of Stock [Line Items]
Common Stock, Shares Authorized				800,000,000	800,000,000
Common Stock, par value				$ 0.01	$ 0.01
Fair Value Of Mezzanine Equity			$ 36,750
Preferred Stock, Shares Authorized				25,000,000	25,000,000
Preferred Stock, par value				$ 0.01	$ 0.01
Preferred Stock, Shares Outstanding				0	0
Redeemable Class A Unit | Chief Executive Officer
Subsidiary Sale Of Stock [Line Items]
Shares, Issued				35,000,000
Common Stock [Member]
Subsidiary Sale Of Stock [Line Items]
Conversion of Stock		10,234,000
IPO
Subsidiary Sale Of Stock [Line Items]
Shares Issued, Price Per Share				$ 18
Preferred Stock, Shares Authorized				25,000,000
Preferred Stock, par value				$ 0.01
Preferred Stock, Shares Outstanding				0	0
IPO | LifeStance [Member]
Subsidiary Sale Of Stock [Line Items]
Issuance of common , Shares	32,800,000
IPO | Common Stock [Member]
Subsidiary Sale Of Stock [Line Items]
Issuance of common , Shares			32,800
IPO | Maximum
Subsidiary Sale Of Stock [Line Items]
Common Stock, Shares Authorized				800,000,000
IPO | Minimum
Subsidiary Sale Of Stock [Line Items]
Common Stock, Shares Authorized				1,000

Related Party Transactions - Ad

Related Party Transactions - Additional Information (Details) $ in Thousands	3 Months Ended	9 Months Ended
	Jun. 30, 2021 USD ($)	Sep. 30, 2022 USD ($) Facility	Sep. 30, 2021 USD ($)
Subsidiary Or Equity Method Investee [Line Items]
Number of office facilities | Facility		19
Clinicians expiration		2030
Related-party management fees			$ 1,445
Related party fees		$ 4,375
Management fee	$ 0

Related Party Transactions - Sc

Related Party Transactions - Schedule of Related Party Rent Expenses (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Related Party Transactions [Abstract]
Rent expense	$ 397	$ 809	$ 1,175	$ 2,006

Related Party Transactions - _2

Related Party Transactions - Schedule of Future Minimum Operating Lease Payments (Details) $ in Thousands	Sep. 30, 2022 USD ($)
Related Party Transactions [Abstract]
Remainder of 2022	$ 421
2023	539
2024	1,489
2025	1,513
2026	1,604
Thereafter	503
Total	$ 6,069

Commitments and Contingencies -

Commitments and Contingencies - Schedule of Maximum Contingent Consideration Based on the Acquisition Agreements (Details) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2022	Dec. 31, 2021
Commitments and Contingencies Disclosure [Abstract]
Beginning Balance	$ 17,430	$ 16,414
Additions related to acquisitions	7,719	10,685
Payments of contingent consideration	(12,290)	(12,279)
(Gain) loss on remeasurement	(562)	2,610
Ending Balance	$ 12,297	$ 17,430

Commitments and Contingencies_2

Commitments and Contingencies - Additional Information (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2022 USD ($)
Commitments and Contingencies Disclosure [Abstract]
Lease expiration year	2032
Medical malpractice insurance, coverage per claim limit	$ 3,000
Medical malpractice insurance, annual coverage per clinician	$ 8,000

Commitments and Contingencies_3

Commitments and Contingencies - Schedule of Related-party Rent Expense (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Loss Contingencies [Line Items]
Total rent expense	$ 13,826	$ 8,429	$ 37,122	$ 22,533
Center Costs Excluding Depreciation and Amortization
Loss Contingencies [Line Items]
Total rent expense	13,421	8,302	36,439	21,878
General And Administrative Expense
Loss Contingencies [Line Items]
Total rent expense	$ 405	$ 127	$ 683	$ 655

Commitments and Contingencies_4

Commitments and Contingencies - Summary of Future Minimum Lease Payments (Details) $ in Thousands	Sep. 30, 2022 USD ($)
Business Acquisition, Contingent Consideration [Line Items]
Remainder of 2022	$ 421
2023	539
2024	1,489
2025	1,513
2026	1,604
Thereafter	503
Total	6,069
Contingent Consideration [Member]
Business Acquisition, Contingent Consideration [Line Items]
Remainder of 2022	14,449
2023	59,245
2024	56,750
2025	53,070
2026	46,583
Thereafter	68,862
Total	$ 298,959

Net Loss Per Share - Schedule o

Net Loss Per Share - Schedule of Basic and Diluted Net Loss Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Earnings Per Share [Abstract]
Net loss available to common stockholders'/members'	$ (37,853)	$ (120,452)	$ (168,908)	$ (235,917)
Weighted-average shares used to compute basic and diluted net loss per share	357,520	343,394	354,057	321,283
Net loss per share, basic	$ (0.11)	$ (0.35)	$ (0.48)	$ (0.73)
Net loss per share, diluted	$ (0.11)	$ (0.35)	$ (0.48)	$ (0.73)

Net Loss Per Share - Computatio

Net Loss Per Share - Computation of Diluted Net Loss per Share (Details) - shares	9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Diluted net loss per share	44,042	36,957
Restricted Stock Awards (RSAs) [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Diluted net loss per share	17,372	30,749
Restricted Stock Units (RSUs) [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Diluted net loss per share	14,444	6,208
Stock Options [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Diluted net loss per share	12,226	0

Subsequent Events - Additional

Subsequent Events - Additional Information (Details) - Maximum [Member] $ in Thousands	9 Months Ended
	Sep. 30, 2022 USD ($)
Business Acquisition [Line Items]
Cash consideration	$ 18,740
Contingent consideration	$ 2,475