Oscar Health (OSCR) 10-Q 14 May 21 2021 Q1 Quarterly report Financial data

Cover

Cover - shares	3 Months Ended
	Mar. 31, 2021	Apr. 30, 2021
Document Information [Line Items]
Document Type	10-Q
Document Period End Date	Mar. 31, 2021
Document Quarterly Report	true
Document Transition Report	false
Entity File Number	001-40154
Entity Registrant Name	Oscar Health, Inc.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	46-1315570
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	Q1
Current Fiscal Year End Date	--12-31
Amendment Flag	false
Entity Central Index Key	0001568651
Entity Address, Address Line One	75 Varick Street, 5th Floor
Entity Address, City or Town	New York,
Entity Address, State or Province	NY
Entity Address, Postal Zip Code	10013
City Area Code	(646)
Local Phone Number	403-3677
Title of 12(b) Security	Class A Common Stock, $0.00001 par value per share
Trading Symbol	OSCR
Security Exchange Name	NYSE
Entity Current Reporting Status	No
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	true
Entity Ex Transition Period	false
Entity Shell Company	false
Class A
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		172,266,017
Class B
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		35,115,807

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Current Assets:
Cash and cash equivalents	$ 2,321,287	$ 826,326
Short-term investments	389,016	366,387
Premium and other receivables	75,851	65,322
Risk adjustment transfer receivable	37,765	31,157
Accrued investment income	1,445	1,862
Balances due from reinsurance programs	353,996	579,393
Total current assets	3,179,360	1,870,447
Property, equipment, and capitalized software, net	38,993	35,812
Long-term investments	329,597	325,740
Restricted deposits	26,449	26,478
Other assets	19,472	13,136
Net deferred tax asset	485	493
Total Assets	3,594,356	2,272,106
Current Liabilities:
Benefits payable	358,066	311,914
Risk adjustment transfer payable	922,069	716,370
Premium deficiency reserve	75,029	84,571
Unearned premiums	71,946	71,904
Accounts payable and accrued liabilities	120,954	137,524
Reinsurance payable	260,055	343,313
Total current liabilities	1,808,119	1,665,596
Long-term debt	0	142,487
Warrant liabilities	0	15,005
Total liabilities	1,808,119	1,823,088
Commitments and contingencies (Note 15)
Convertible Preferred Stock, $0.00001 par value; 407,156,831 shares authorized; 400,904,302 shares issued and outstanding as of December 31, 2020	0	1,744,911
Stockholders' Equity (Deficit)
Preferred stock, $0.00001 par value; 82,500,000 shares authorized, none issued or outstanding as of March 31, 2021	0	0
Common stock		2
Treasury stock at (314,600 shares as of March 31, 2021 and December 31, 2020)	(2,923)	(2,923)
Additional paid-in capital	3,303,031	133,255
Accumulated deficit	(1,514,477)	(1,427,106)
Accumulated other comprehensive income (loss)	604	879
Total Stockholders’ Equity (Deficit)	1,786,237	(1,295,893)
Total Liabilities, Convertible Preferred Stock and Stockholders' Equity (Deficit)	3,594,356	$ 2,272,106
Class A
Stockholders' Equity (Deficit)
Common stock	2
Class B
Stockholders' Equity (Deficit)
Common stock	$ 0

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - $ / shares	Mar. 31, 2021	Dec. 31, 2020
Convertible preferred stock, par value (in dollars per share)		$ 0.00001
Convertible preferred stock, shares authorized		407,156,831
Convertible preferred stock, shares issued		400,904,302
Convertible preferred stock, shares outstanding	0	400,904,302
Preferred stock, par value (in dollars per share)	$ 0.00001
Preferred stock, shares authorized	82,500,000
Preferred stock, shares issued	0
Preferred stock, shares outstanding	0
Treasury stock (in shares)	314,600	314,600
Class A
Common stock, par value (in dollars per share)	$ 0.00001
Common stock, shares authorized	825,000,000
Common stock, shares issued	172,060,630
Common stock, shares outstanding	172,060,630
Class B
Common stock, par value (in dollars per share)	$ 0.00001
Common stock, shares authorized	82,500,000
Common stock, shares issued	35,115,807
Common stock, shares outstanding	35,115,807
Series A common stock
Common stock, par value (in dollars per share)		$ 0.00001
Common stock, shares authorized		680,000,000
Common stock, shares issued		8,291,917
Common stock, shares outstanding		8,291,917
Series B common stock
Common stock, par value (in dollars per share)		$ 0.00001
Common stock, shares authorized		69,487,963
Common stock, shares issued		23,162,654
Common stock, shares outstanding		23,162,654
Series C common stock
Common stock, par value (in dollars per share)		$ 0.00001
Common stock, shares authorized		10,000,000
Common stock, shares issued		0
Common stock, shares outstanding		0

Consolidated Statements of Oper

Consolidated Statements of Operations - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Revenue
Premiums before ceded reinsurance	$ 610,099	$ 424,448
Reinsurance premiums ceded	(241,562)	(339,229)
Premiums earned	368,537	85,219
Investment income and other revenue	851	2,884
Total revenue	369,388	88,103
Operating Expenses
Claims incurred, net	268,048	84,216
Other insurance cost (including non-cash stock-based compensation expense of $9.7 million and $4.1 million as of March 31, 2021 and 2020, respectively)	79,837	40,904
General and administrative expenses (including non-cash stock-based compensation expense of $9.4 million and $4.0 million as of March 31, 2021 and 2020, respectively)	63,062	31,839
Federal and state assessments	30,515	22,297
Health insurance industry fee	0	4,813
Premium deficiency reserve release	(9,543)	(18)
Total operating expenses	431,919	184,051
Loss from operations	(62,531)	(95,948)
Interest expense	3,697	0
Debt extinguishment loss	20,178	0
Loss before income taxes	(86,406)	(95,948)
Income tax provision	965	931
Net loss	$ (87,371)	$ (96,879)
Earnings (Loss) per Share
Net loss per share, basic (in dollars per share)	$ (0.98)	$ (3.36)
Net loss per share, diluted (in dollars per share)	$ (0.98)	$ (3.36)
Weighted average common shares outstanding, basic	88,865,726	28,874,520
Weighted-average common shares outstanding, diluted	88,865,726	28,874,520

Consolidated Statements of Op_2

Consolidated Statements of Operations (Parenthetical) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Stock-based compensation expense	$ 19.1	$ 8.1
Other insurance cost
Stock-based compensation expense	9.7	4.1
General and administrative expense
Stock-based compensation expense	$ 9.4	$ 4

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Statement of Comprehensive Income [Abstract]
Net loss	$ (87,371)	$ (96,879)
Other comprehensive income (loss), net of tax:
Net unrealized gains (losses) on securities available for sale	(275)	1,529
Comprehensive loss	$ (87,646)	$ (95,350)

Consolidated Statements of Conv

Consolidated Statements of Convertible Preferred Stock and Stockholders' Equity (Deficit) - USD ($) $ in Thousands	Total	Common Stock	Common StockClass A	Common StockClass B	Treasury Stock	Additional Paid-In Capital	Accumulated Deficit	Accumulated Other Comprehensive Income (Loss)
Beginning balance (in shares) at Dec. 31, 2019	335,625,349
Beginning balance at Dec. 31, 2019	$ 1,295,744
Ending balance (in shares) at Mar. 31, 2020	335,625,349
Ending balance at Mar. 31, 2020	$ 1,295,744
Beginning balance (in shares) at Dec. 31, 2019		28,840,849
Beginning balance at Dec. 31, 2019	(945,138)	$ 2			$ (2,923)	$ 70,673	$ (1,012,863)	$ (27)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock upon exercise of options (in shares)		55,226
Issuance of common stock upon exercise of options	443					443
Stock-based compensation expense	8,096					8,096
Net unrealized gains (losses) on securities available for sale	1,529							1,529
Net loss	(96,879)						(96,879)
Ending balance (in shares) at Mar. 31, 2020		28,896,075
Ending balance at Mar. 31, 2020	$ (1,031,949)	$ 2			(2,923)	79,212	(1,109,742)	1,502
Beginning balance (in shares) at Dec. 31, 2020	400,904,302
Beginning balance at Dec. 31, 2020	$ 1,744,911
Increase (Decrease) in Temporary Equity [Roll Forward]
Conversion of pre-IPO shares to Class A and Class B common stock (in shares)	(400,904,302)
Conversion of pre-IPO shares to Class A and Class B common stock	$ (1,744,911)
Ending balance (in shares) at Mar. 31, 2021	0
Ending balance at Mar. 31, 2021	$ 0
Beginning balance (in shares) at Dec. 31, 2020		31,409,202	0	0
Beginning balance at Dec. 31, 2020	(1,295,893)	$ 2	$ 0	$ 0	(2,923)	133,255	(1,427,106)	879
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Conversion of pre-IPO shares to Class A and Class B common stock (in shares)		(31,409,202)	130,280,651	35,115,807
Conversion of pre-IPO shares to Class A and Class B common stock	1,744,910	$ (2)	$ 1			1,744,911
Issuance of common stock upon IPO, net of underwriting discount (in shares)			36,391,946
Issuance of common stock upon IPO, net of underwriting discount	1,338,875		$ 1			1,338,874
Issuance of common stock upon exercise of warrants and call options (in shares)			1,115,973
Issuance of common stock upon exercise of warrants and call options	$ 37,071					37,071
Issuance of common stock upon exercise of options (in shares)	4,306,297		4,272,060
Issuance of common stock upon exercise of options	$ 29,805					29,805
Stock-based compensation expense	19,115					19,115
Net unrealized gains (losses) on securities available for sale	(275)							(275)
Net loss	(87,371)						(87,371)
Ending balance (in shares) at Mar. 31, 2021		0	172,060,630	35,115,807
Ending balance at Mar. 31, 2021	$ 1,786,237	$ 0	$ 2	$ 0	$ (2,923)	$ 3,303,031	$ (1,514,477)	$ 604

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Cash flows from operating activities:
Net loss	$ (87,371)	$ (96,879)
Adjustments to reconcile net loss to net cash used in operating activities:
Deferred taxes	8	120
Net realized gain on sale of financial instruments	(113)	(654)
(Gain) loss on fair value of warrant liabilities	12,856	(860)
Depreciation and amortization expense	3,403	2,544
Amortization of debt issuance costs	329	0
Stock-based compensation expense	19,115	8,096
Investment amortization, net of accretion	1,074	155
Debt extinguishment loss	20,178	0
(Increase) / decrease in:
Premium and other receivables	(10,529)	(75,271)
Risk adjustment transfer receivable	(6,608)	(11,151)
Accrued investment income	417	322
Balances due from reinsurance programs	225,397	(92,900)
Other assets	(6,336)	(14,823)
Increase / (decrease) in:
Benefits payable	46,152	96,423
Unearned premiums	42	(2,855)
Premium deficiency reserve	(9,542)	(18)
Accounts payable and accrued liabilities	(13,222)	15,461
Reinsurance payable	(83,258)	119,881
Risk adjustment transfer payable	205,699	158,759
Net cash provided by operating activities	317,691	106,350
Cash flows from investing activities:
Purchase of fixed maturity securities	(245,694)	(150,752)
Sale of investments	83,798	163,887
Maturity of investments	134,199	39,211
Purchase of property, equipment and capitalized software	(6,583)	(3,978)
Change in restricted deposits	0	(356)
Net cash (used in) provided by investing activities	(34,280)	48,012
Cash flows from financing activities:
Debt prepayment	(153,173)	0
Debt extinguishment costs	(12,994)	0
Proceeds from IPO, net of underwriting discounts	1,348,321	0
Offering costs from IPO	(9,447)	0
Proceeds from exercise of warrants and call options	9,191	0
Proceeds from exercise of stock options	29,652	442
Net cash provided by financing activities	1,211,550	442
Increase in cash, cash equivalents and restricted cash equivalents	1,494,961	154,804
Cash, cash equivalents, restricted cash and cash equivalents—Beginning of period	843,105	353,380
Cash, cash equivalents, restricted cash and cash equivalents—end of period	2,338,066	508,184
Total cash, cash equivalents and restricted cash and cash equivalents	2,338,066	508,184
Supplemental Disclosures:
Interest payments	3,553	0
Non-cash investing and financing activities:
Conversion of redeemable convertible preferred stock to common stock upon initial public offering	1,744,911	0
Net exercise of preferred stock warrants to preferred stock upon initial public offering	28,248	0
Adjustment to fair value of preferred stock warrant liability upon initial public offering	$ (13,243)	$ 0

ORGANIZATION

ORGANIZATION	3 Months Ended
	Mar. 31, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
ORGANIZATION	ORGANIZATION Oscar Health, Inc. ("Oscar" or the "Company") is the first health insurance company built around a full stack technology platform and a relentless focus on serving its members. Headquartered in New York City, Oscar offers Individual & Family, Small Group and Medicare Advantage plans. The Company operates as one segment to sell insurance to its members directly, as well as through the state-run health care exchanges formed in conjunction with the Patient Protection and Affordable Care Act ("ACA") via its health insurance subsidiaries. The Company provides plans in the Medicare Advantage program to adults who are age 65 and older and eligible for traditional Medicare but who instead select coverage through a private market plan. The Company has also partnered with Cigna through the Cigna + Oscar partnership, which unites Oscar’s highly-differentiated member experience with Cigna’s broad provider networks, to exclusively serve the Small Group employer market. Initial Public Offering On March 2, 2021, the Company's registration statement on Form S-1 (the “IPO Registration Statement”) related to its initial public offering (“IPO”) was declared effective and the Company’s Class A common stock, par value $0.00001 per share (the “Class A Common Stock”) began trading on the New York Stock Exchange on March 3, 2021. On March 5, 2021, the Company completed its IPO, in which the Company sold 36,391,946 shares of Class A Common Stock at a price to the public of $39.00 per share. The Company received aggregate net proceeds of $1.3 billion after deducting underwriting discounts and commissions of $71.0 million. The Company used a portion of the net proceeds of the IPO to repay in full outstanding borrowings, including fees and expenses, under the Term Loan Facility. Refer to Note 9 - Debt and Warrants for more information. The Company's Class A Common Stock is traded on the New York Stock Exchange under the symbol "OSCR." Reclassification and Reverse Stock Split In connection with its IPO, on March 3, 2021, the Company filed an amended and restated certificate of incorporation (the “Amended and Restated Certificate of Incorporation”) with the Secretary of State of the State of Delaware, which effected a reclassification of the Company’s issued and outstanding share capital and a one-for-three reverse stock split. Upon conversion of all outstanding shares of convertible preferred stock, and upon filing of the Company’s Amended and Restated Certificate of Incorporation, all outstanding shares of each series of the Company’s convertible preferred stock and common stock issued and outstanding prior to the IPO converted and/or were reclassified into an aggregate of 132,760,639 shares of Class A Common Stock and 35,335,579 shares of Class B common stock, par value $0.00001 per share (the “Class B Common Stock.”), and 943,800 shares of common stock held in treasury were reclassified into an aggregate of 314,600 shares of Class A Common Stock. In accordance with accounting principles generally accepted in the United States (“ U.S. GAAP”), all shares of common stock and per share data that are presented in this Quarterly Report on Form 10-Q have been adjusted to reflect the reclassification and reverse stock split on a retroactive basis for all periods presented. Shares of convertible preferred stock presented in this Quarterly Report on Form 10-Q have not been adjusted for the reclassification or reverse stock split, as these shares were converted to common stock prior to the reclassification and reverse stock split. For additional information, see Note 11 - Stockholders’ Equity. Basis of Presentation The accompanying interim condensed consolidated financial statements of the Company are unaudited. These interim unaudited condensed consolidated financial statements have been prepared in accordance with U.S. GAAP, and the applicable rules and regulations of the Securities and Exchange Commission ("SEC") for interim financial information. As such, these financial statements do not include all information and footnotes required by U.S. GAAP for complete financial statements. These condensed consolidated financial statements are unaudited; however, in the opinion of management, they reflect all adjustments consisting only of normal recurring adjustments necessary to state fairly the information presented for the periods presented in conformity with U.S. GAAP applicable to interim periods. The results of operations for the interim periods presented are not necessarily indicative of results for the full year or future periods. These unaudited condensed consolidated financial statements should be read in conjunction with the audited consolidated financial statements and the related notes thereto as of and for the year ended December 31, 2020 included in the prospectus dated March 2, 2021 (File No. 333-252809) (the "Prospectus"), as filed with the SEC pursuant to Rule 424(b)(4) under the Securities Act of 1933, as amended. Use of Estimates The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the amounts reported in the unaudited consolidated financial statements and accompanying notes. Significant estimates inherent in the preparation of the accompanying unaudited consolidated financial statements include healthcare costs incurred but not yet reported (“IBNR”), reinsurance, premium deficiency reserve (“PDR”), risk adjustment, stock-based compensation, premium receivable allowance and income taxes. Estimates are based on past experience and other considerations reasonable under the circumstances. Actual results may differ materially from these estimates. Additionally, the full extent to which the outbreak of COVID-19 could impact the Company’s business, results of operations and financial condition is still unknown and will depend on future developments, which are highly uncertain and cannot be predicted. However, the Company has made accounting estimates based on the facts and circumstances available as of the reporting date. The Company has not currently experienced significant negative impact to its operations, liquidity or capital resources as a result of the COVID-19 pandemic.

RECENT ACCOUNTING PRONOUNCEMENT

RECENT ACCOUNTING PRONOUNCEMENTS	3 Months Ended
	Mar. 31, 2021
Accounting Changes and Error Corrections [Abstract]
RECENT ACCOUNTING PRONOUNCEMENTS	RECENT ACCOUNTING PRONOUNCEMENTS Accounting Pronouncements - Recently Adopted In August 2018, the Financial Accounting Standards Board ("FASB") issued ASU 2018-13, “Fair Value Measurement (Topic 820): Disclosure Framework-Changes to the Disclosure Requirements for Fair Value Measurement,” (“ASU 2018-13”). The amendments in ASU 2018-13 eliminate, add, and modify certain disclosure requirements for fair value measurements. The amendments are effective for interim and annual periods beginning after December 15, 2019, with early adoption permitted for either the entirety of ASU 2018-13 or only the provisions that eliminate or modify disclosure requirements. The Company adopted the standard effective January 1, 2020. The adoption of this standard did not have a material impact on the Company's consolidated financial statements. In November 2018, the FASB issued ASU 2018-18, “Collaborative Arrangements (Topic 808): Clarifying the Interaction Between Topic 808 and Topic 606” (“ASU 2018-18”). The amendments in ASU 2018-18 clarify that certain transactions between collaborative arrangement participants should be accounted for as revenue under ASC 606 when the collaborative arrangement participant is a customer in the context of a unit of account. The amendments under ASU 2018-18 are effective for interim and annual fiscal periods beginning after December 15, 2019, with early adoption permitted. The amendments in ASU 2018-18 should be applied retrospectively to the date of initial application of ASC 606. The Company adopted the standard effective January 1, 2020. The adoption of this standard did not have a material impact on the Company's consolidated financial statements. Accounting Pronouncements - Not Yet Adopted From time to time, new accounting pronouncements are issued by the FASB or other standard setting bodies that the Company adopts as of the specified effective date. 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 it (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, these financial statements may not be comparable to companies that comply with the new or revised accounting pronouncements as of public company effective dates. In February 2016, the (FASB) issued (ASU) 2016- 02, “Leases (Topic 842)” (ASU 2016-02). Under ASU 2016-02, an entity will be required to recognize assets and liabilities for the rights and obligations created by leases on the entity’s balance sheet for both finance and operating leases. For leases with a term of 12 months or less, an entity can elect to not recognize lease assets and lease liabilities and expense the lease over a straight-line basis for the term of the lease. ASU 2016-02 will require new disclosures that depict the amount, timing, and uncertainty of cash flows pertaining to an entity’s leases. Companies are required to adopt the new standard using a modified retrospective approach for annual and interim periods beginning after December 15, 2018. In June 2020, the FASB issued guidance extending the effective date for all entities for which these standards are either currently or imminently effective. This guidance is effective for the Company for annual periods beginning after December 15, 2021. Early adoption is permitted. The Company is currently evaluating the effect that the adoption of ASU 2016-02 will have on its consolidated financial statements. In June 2016, the FASB issued ASU 2016-13, " Financial Instruments - Credit Losses (Topic 326) " (“ASU 2016-13”), which requires entities to use a current expected credit loss model, which is a new impairment model based on expected losses rather than incurred losses. Under this model, an entity would recognize an impairment allowance equal to its current estimate of all contractual cash flows that the entity does not expect to collect from financial assets measured at amortized cost. The entity's estimate would consider relevant information about past events, current conditions, and reasonable and supportable forecasts, which will result in recognition of lifetime expected credit losses upon loan origination. In November 2018, the FASB issued ASU No. 2018-19, “ Codification Improvements to Topic 326, Financial Instruments-Credit Losses ,” which narrowed the scope and changed the effective date for non-public entities for ASU 2016-13. The FASB subsequently issued supplemental guidance within ASU No. 2019-05, “ Financial Instruments-Credit Losses (Topic 326): Targeted Transition Relief ” (‘‘ASU 2019-05’’). ASU 2019-05 provides an option to irrevocably elect the fair value option for certain financial assets previously measured at amortized cost basis. In November 2019, the FASB issued ASU 2019-11, “ Codification Improvements to Topic 326, Financial Instruments - Credit Losses ” (“ASU 2019-11”) guidance extending the effective date for all non-public business entities. In May 2019, the FASB issued ASU 2019-05, “ Financial Instruments - Credit Losses (Topic 326): Targeted Transition Relief .” In April 2019, the FASB issued ASU 2019-04, “ Codification Improvements to Topic 326, Financial Instruments - Credit Losses, Topic 815, Derivatives and Hedging, and Topic 825, Financial Instruments. ” These updates provide an option to irrevocably elect to measure certain individual financial assets at fair value instead of amortized cost and provide additional clarification and implementation guidance on certain aspects of the previously issued ASU 2016-13 and have the same effective date and transition requirements as ASU 2016-13. The effect of a prospective transition approach is to maintain the same amortized cost basis before and after the date of adoption. ASU 2016-13 is effective for the Company for annual periods beginning after December 15, 2022. Early adoption is permitted. The Company is currently assessing the effect that the adoption of ASU 2016-13 will have on its consolidated financial statements. In December 2019, the FASB issued ASU 2019-12, “Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes” (“ASU 2019-12”). The amendments in ASU 2019-12 remove certain exceptions to the general principles in ASC Topic 740. The amendments also clarify and amend existing guidance to improve consistent application. The amendments are effective for the Company’s annual reporting periods beginning after December 15, 2021. Early adoption is permitted. The transition method (retrospective, modified retrospective, or prospective basis) related to the amendments depends on the applicable guidance, and all amendments for which there is no transition guidance specified are to be applied on a prospective basis. The Company is currently evaluating the effects the adoption of ASU 2019-12 will have on its consolidated financial statements.

PREMIUMS EARNED

PREMIUMS EARNED	3 Months Ended
	Mar. 31, 2021
Insurance [Abstract]
PREMIUMS EARNED	PREMIUMS EARNED Three Months Ended March 31, 2021 March 31, 2020 Premiums Earned: (in thousands) Direct policy premiums $ 820,814 $ 572,011 Assumed premiums 2,411 — Direct and assumed premiums 823,225 572,011 Risk adjustment (213,126) (147,563) Premiums before ceded reinsurance 610,099 424,448 Reinsurance premiums ceded (241,562) (339,229) Total premiums earned $ 368,537 $ 85,219 For the three months ended March 31, 2021 and 2020, $561.5 million and $335.6 million, respectively, of direct policy premiums were received directly from CMS as part of APTC and Medicare Advantage. REINSURANCE The Company has entered into quota share reinsurance agreements with two reinsurers under which the reinsurer assumes an agreed percentage of the underlying policies being reinsured and shares all premiums and incurred claims accordingly. Under the 2021 agreements, all premiums and claims ceded under the Company's quota share arrangements are shared proportionally with the reinsurers. Under the 2020 agreements, premiums and claims ceded are shared proportionally with the reinsurers, up to a limit specified in each agreement (the limit was removed from the 2021 agreements effective as of January 1, 2021). As part of the 2020 and 2021 agreements, the Company receives ceding commissions, which are calculated based on a percentage of ceded premiums, and experience refunds (resulting from actual claims experience being lower than a specified threshold). The composition of total reinsurance premiums ceded and reinsurance premiums assumed, which are included as components of total earned premiums in the consolidated statement of operations, is as follows: Three Months Ended March 31, 2021 March 31, 2020 (In thousands) Reinsurance premiums ceded, gross $ (264,787) $ (357,710) Experience refunds 23,225 18,481 Reinsurance premiums ceded (241,562) (339,229) Reinsurance premiums assumed 2,411 — Total reinsurance premiums ceded and assumed $ (239,151) $ (339,229) The Company records claims expense net of reinsurance recoveries. The following table reconciles the total claims expense to the net claims expense as presented in the consolidated statement of operations: Three Months Ended March 31, 2021 March 31, 2020 (In thousands) Direct claims incurred $ 457,219 $ 345,508 Ceded reinsurance claims (190,948) (261,290) Assumed reinsurance claims 1,777 (2) Total claims incurred, net $ 268,048 $ 84,216 The Company records selling, general and administrative expenses net of ceding commissions. The following table reconciles total other insurance costs to the amount presented in the consolidated statement of operations: Three Months Ended March 31, 2021 March 31, 2020 (In thousands) Other insurance costs, gross $ 99,143 $ 75,930 Ceding commissions (19,306) (35,026) Other insurance costs, net $ 79,837 $ 40,904 The Company records reinsurance recoverables as “balances due from reinsurance programs” within current assets on its consolidated balance sheets. The composition of the reinsurance recoverables balance is as follows: March 31, 2021 December 31, 2020 (In thousands) Ceded reinsurance claim recoverables $ 307,943 $ 435,331 Reinsurance ceding commissions 27,469 41,586 Experience refunds on reinsurance agreements 18,584 102,476 Balances due from reinsurance programs $ 353,996 $ 579,393 The Company regularly evaluates the financial condition of its reinsurers to minimize exposure to significant losses. A key credit quality indicator for reinsurance is the A.M. Best Company (“A.M. Best”) financial strength ratings of the reinsurer. A.M. Best financial strength ratings are an independent opinion of a reinsurer’s ability to meet ongoing obligations to policyholders. The Company's reinsurers have A.M. Best ratings from A++ to AA-.

REINSURANCE

REINSURANCE	3 Months Ended
	Mar. 31, 2021
Insurance [Abstract]
PREMIUMS EARNED	PREMIUMS EARNED Three Months Ended March 31, 2021 March 31, 2020 Premiums Earned: (in thousands) Direct policy premiums $ 820,814 $ 572,011 Assumed premiums 2,411 — Direct and assumed premiums 823,225 572,011 Risk adjustment (213,126) (147,563) Premiums before ceded reinsurance 610,099 424,448 Reinsurance premiums ceded (241,562) (339,229) Total premiums earned $ 368,537 $ 85,219 For the three months ended March 31, 2021 and 2020, $561.5 million and $335.6 million, respectively, of direct policy premiums were received directly from CMS as part of APTC and Medicare Advantage. REINSURANCE The Company has entered into quota share reinsurance agreements with two reinsurers under which the reinsurer assumes an agreed percentage of the underlying policies being reinsured and shares all premiums and incurred claims accordingly. Under the 2021 agreements, all premiums and claims ceded under the Company's quota share arrangements are shared proportionally with the reinsurers. Under the 2020 agreements, premiums and claims ceded are shared proportionally with the reinsurers, up to a limit specified in each agreement (the limit was removed from the 2021 agreements effective as of January 1, 2021). As part of the 2020 and 2021 agreements, the Company receives ceding commissions, which are calculated based on a percentage of ceded premiums, and experience refunds (resulting from actual claims experience being lower than a specified threshold). The composition of total reinsurance premiums ceded and reinsurance premiums assumed, which are included as components of total earned premiums in the consolidated statement of operations, is as follows: Three Months Ended March 31, 2021 March 31, 2020 (In thousands) Reinsurance premiums ceded, gross $ (264,787) $ (357,710) Experience refunds 23,225 18,481 Reinsurance premiums ceded (241,562) (339,229) Reinsurance premiums assumed 2,411 — Total reinsurance premiums ceded and assumed $ (239,151) $ (339,229) The Company records claims expense net of reinsurance recoveries. The following table reconciles the total claims expense to the net claims expense as presented in the consolidated statement of operations: Three Months Ended March 31, 2021 March 31, 2020 (In thousands) Direct claims incurred $ 457,219 $ 345,508 Ceded reinsurance claims (190,948) (261,290) Assumed reinsurance claims 1,777 (2) Total claims incurred, net $ 268,048 $ 84,216 The Company records selling, general and administrative expenses net of ceding commissions. The following table reconciles total other insurance costs to the amount presented in the consolidated statement of operations: Three Months Ended March 31, 2021 March 31, 2020 (In thousands) Other insurance costs, gross $ 99,143 $ 75,930 Ceding commissions (19,306) (35,026) Other insurance costs, net $ 79,837 $ 40,904 The Company records reinsurance recoverables as “balances due from reinsurance programs” within current assets on its consolidated balance sheets. The composition of the reinsurance recoverables balance is as follows: March 31, 2021 December 31, 2020 (In thousands) Ceded reinsurance claim recoverables $ 307,943 $ 435,331 Reinsurance ceding commissions 27,469 41,586 Experience refunds on reinsurance agreements 18,584 102,476 Balances due from reinsurance programs $ 353,996 $ 579,393 The Company regularly evaluates the financial condition of its reinsurers to minimize exposure to significant losses. A key credit quality indicator for reinsurance is the A.M. Best Company (“A.M. Best”) financial strength ratings of the reinsurer. A.M. Best financial strength ratings are an independent opinion of a reinsurer’s ability to meet ongoing obligations to policyholders. The Company's reinsurers have A.M. Best ratings from A++ to AA-.

RESTRICTED CASH AND RESTRICTED

RESTRICTED CASH AND RESTRICTED DEPOSITS	3 Months Ended
	Mar. 31, 2021
Cash and Cash Equivalents [Abstract]
RESTRICTED CASH AND RESTRICTED DEPOSITS	RESTRICTED CASH AND RESTRICTED DEPOSITS As a condition for licensure, the Company is required to maintain certain funds on deposit or pledged to various state agencies. These funds consist of cash, cash equivalents and investments, which are recorded at fair value. The states require that these funds remain on deposit for an indefinite period-of-time and, therefore, the Company classifies these restricted deposits as long-term regardless of the contractual maturity date of the securities held. March 31, 2021 December 31, 2020 (in thousands) Restricted cash and cash equivalents $ 16,779 $ 16,779 Restricted investments 9,670 9,699 Restricted Deposits, as reported on the balance sheet $ 26,449 $ 26,478

INVESTMENTS

INVESTMENTS	3 Months Ended
	Mar. 31, 2021
Investments, Debt and Equity Securities [Abstract]
INVESTMENTS	INVESTMENTSThe following tables provide summaries of investments by major security type: March 31, 2021 Amortized Cost Unrealized Gains Unrealized Losses Fair Value (in thousands) U.S. treasury and agency securities $ 529,333 $ 476 $ (30) $ 529,779 Corporate notes 177,190 165 (95) 177,260 Certificate of deposit 2,370 — — 2,370 Commercial paper 6,044 — — 6,044 Municipalities 3,160 — — 3,160 Total $ 718,097 $ 641 $ (125) $ 718,613 December 31, 2020 Amortized Cost Unrealized Gains Unrealized Losses Fair Value (in thousands) U.S. treasury and agency securities $ 523,809 $ 562 $ (2) $ 524,369 Corporate notes 159,461 262 (58) 159,665 Certificate of deposit 7,043 — — 7,043 Commercial paper 1,050 — — 1,050 Total $ 691,363 $ 824 $ (60) $ 692,127 At March 31, 2021, and December 31, 2020 the securities classified as current available-for-sale mature within one year or less. There are no available-for-sale securities that have been in a continuous unrealized loss position for longer than twelve months. The current securities that mature within one year or less in a gross unrealized loss position are as follows: March 31, 2021 Number of Securities Fair Value Gross (in thousands) Investments twelve months or less: Corporate notes 67 37,238 (5) Total 67 $ 37,238 $ (5) December 31, 2020 Number of Securities Fair Value Gross (in thousands) Investments twelve months or less: U.S. treasury and agency securities 51 $ 339,014 $ (2) Corporate notes 40 19,280 (3) Total 91 $ 358,294 $ (5) Long-term securities that mature over twelve months or more in a gross unrealized loss position are as follows: March 31, 2021 Number of Securities Fair Value Gross (in thousands) Investments over twelve months: U.S. treasury and agency securities 33 $ 186,160 $ (30) Corporate notes 192 140,021 (90) Total 225 $ 326,181 $ (120) December 31, 2020 Number of Securities Fair Value Gross (in thousands) Investments over twelve months: Corporate notes 189 140,384 (55) Total 189 $ 140,384 $ (55) Net investment income was attributable to the following: Three Months Ended March 31, 2021 March 31, 2020 (in thousands) Interest income $ 1,345 $ 2,385 Investment discount amortization net of premium accretion (1,074) (155) Net realized gain 113 654 Total $ 384 $ 2,884 The Company regularly evaluates its investments in debt securities to determine if a decline in value is other-than-temporary. When evaluating these declines, the Company assesses the severity of the loss relative to its original cost and the time that the market value has been less than its original cost, and considers the Company’s intent to retain the investments for a long enough period to allow for a sufficient market recovery. If a decline in the value of a debt security is considered other-than-temporary, the Company reduces the investment through a charge to the consolidated statement of operations. No adjustments were necessary during the periods presented.

FAIR VALUE

FAIR VALUE	3 Months Ended
	Mar. 31, 2021
Fair Value Disclosures [Abstract]
FAIR VALUE	FAIR VALUE Fair value represents the amount that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants. As such, fair value is a market-based measurement that is determined based on assumptions that market participants would use in pricing an asset or a liability. Assets and liabilities recorded at fair values are measured in accordance with a three-tier fair value hierarchy based on the observability of the inputs available in the market used to measure fair value: • Pricing Level 1 - Quoted prices in active markets for identical assets or liabilities. • Pricing Level 2 - Observable inputs other than quoted prices in active markets for identical assets and liabilities, quoted prices for identical or similar assets or liabilities in inactive markets, or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities. • Pricing Level 3 - Inputs that are generally unobservable and typically reflect management’s estimate of assumptions that market participants would use in pricing the assets or liability. Assets and liabilities measured at fair value on recurring basis are as follows: March 31, 2021 (Level 1) (Level 2) (Level 3) Total Fair Value Measurement (in thousands) Investments U.S. treasury and agency securities $ — $ 529,779 $ — $ 529,779 Corporate notes — 177,259 — 177,259 Commercial paper — 6,044 — 6,044 Certificate of deposit — 2,370 — 2,370 Municipalities — 3,160 — 3,160 Total $ — $ 718,613 $ — $ 718,613 December 31, 2020 (Level 1) (Level 2) (Level 3) Total Fair Value Measurement (in thousands) Investments U.S. treasury and agency securities $ — $ 524,369 $ — $ 524,369 Corporate notes — 159,665 — 159,665 Commercial paper — 7,043 — 7,043 Certificate of deposit — 1,050 — 1,050 Total $ — $ 692,127 $ — $ 692,127 Warrant liabilities $ — $ — $ 15,005 $ 15,005 The Company classifies investments within Level 2 because the Company uses quoted market prices or alternative pricing sources that are based on market observable inputs to determine their fair value. The carrying values of restricted deposits reported on the consolidated balance sheet but not listed in the table above approximate their fair value. Cash and cash equivalents are carried at cost, which approximates fair value. The Company classified warrant liabilities within Level 3 value hierarchy because the liability is based on present value calculations and external valuation models whose inputs include market interest rates, estimated operational capitalization rates, and volatilities. Fair value is determined using an option pricing model. The table below presents changes in the fair value of the Company’s Level 3 warrant liabilities as March 31, 2021 and December 31, 2020 as follows: March 31, 2021 December 31, 2020 (in thousands) Beginning balance $ 15,005 $ 8,819 Vesting of warrants — 392 Change in fair value 13,243 4,709 Preferred Stock Series A11 call options issued — 13,488 Preferred Stock Series A11 call options exercised (70) (12,403) Preferred Stock Series AA, A8, and A9 exercised (28,178) — Ending balance $ — $ 15,005 As of December 31, 2020, the Company classified long-term debt within Level 3 value hierarchy because the fair value of the liability is based upon a market approach with various unobservable inputs such as market price quotations, discount margins, market spreads applied, the terms and liquidity of the instrument, the financial condition, operating results and credit ratings of the issuer or underlying company, the quoted market price of publicly traded securities with similar duration and yield, time value, yield curve, default rates, as well as other measurements. As of December 31, 2020, the fair value approximated the carrying value as the debt was issued near year end and there has been little volatility in interest rates. The long-term debt was paid in full in March 2021 (see Note 9 - Debt and Warrants).

BENEFITS PAYABLE

BENEFITS PAYABLE	3 Months Ended
	Mar. 31, 2021
Insurance [Abstract]
BENEFITS PAYABLE	BENEFITS PAYABLE Reserves for medical claims expenses are estimated using actuarial assumptions and recorded as a benefits payable liability on the consolidated balance sheet. The assumptions for the estimates and for establishing the resulting liability are continuously reviewed, and any adjustments to reserves are reflected in the consolidated statement of operations in the period in which the estimates are updated. The following table provides a rollforward of the Company’s beginning and ending benefits payable and claims adjustment expenses ("CAE") payable balances for the three months ended March 31, 2021 and 2020: As of March 31, 2021 Benefits Payable Unallocated Claims Total (in thousands) Benefits payable, beginning of the period $ 311,914 $ 5,509 $ 317,424 Less: Reinsurance recoverable 132,658 — 132,658 Benefits payable, beginning of the period, net $ 179,256 $ 5,509 $ 184,766 Claims incurred and CAE Current year $ 273,203 $ 16,262 $ 289,465 Prior years (5,155) — (5,155) Total claims incurred and CAE, net $ 268,048 $ 16,262 $ 284,310 Claims paid and CAE Current year $ 167,112 $ 9,943 $ 177,055 Prior years 2,219 5,509 7,728 Total claims and CAE paid, net $ 169,331 $ 15,452 $ 184,783 Benefits and CAE payable, end of period, net $ 277,974 $ 6,319 $ 284,293 Add: Reinsurance recoverable 80,092 — 80,092 Benefits and CAE payable, end of period $ 358,066 $ 6,319 $ 364,385 As of March 31, 2020 Benefits Payable Unallocated Claims Total (in thousands) Benefits payable, beginning of the period $ 156,557 $ 3,009 $ 159,567 Less: Reinsurance recoverable 76,184 — 76,184 Benefits payable, beginning of the period, net $ 80,373 $ 3,009 $ 83,383 Claims incurred and CAE Current year $ 82,573 $ 8,220 $ 90,794 Prior years 1,643 — 1,643 Total claims incurred and CAE, net $ 84,216 $ 8,220 $ 92,437 Claims paid and CAE Current year $ 44,873 $ 3,892 $ 48,765 Prior years 44,030 3,009 47,039 Total claims and CAE paid, net $ 88,903 $ 6,901 $ 95,804 Benefits and CAE payable, end of period, net $ 75,687 $ 4,328 $ 80,016 Add: Reinsurance recoverable 177,293 — 177,293 Benefits and CAE payable, end of period $ 252,980 $ 4,328 $ 257,309

DEBT AND WARRANTS

DEBT AND WARRANTS	3 Months Ended
	Mar. 31, 2021
Debt Disclosure [Abstract]
DEBT AND WARRANTS	DEBT AND WARRANTS Long-Term Debt On October 30, 2020, the Company entered into a credit agreement (“Facility Agreement”) with HPS Investment Partners, LLC (“HPSIP”) whereby HPSIP agreed to provide a $150.0 million first lien term loan (“Term Loan”). The Term Loan had a variable interest rate equal to LIBOR plus 11.75%, per annum, which equated to 12.75% per annum during the period, and a maturity date of October 30, 2024, subject to certain conditions. On March 5, 2021, the Company used proceeds from its recently completed IPO to repay the outstanding balance of $153.2 million on its Term Loan, which included $3.2 million of paid-in-kind interest. A loss on debt extinguishment of $20.2 million was recognized, which consisted of $13.0 million in prepayment penalties and $7.2 million in unamortized debt discount and debt issuance costs. Revolving Credit Facility On February 21, 2021, the Company entered into a senior secured credit agreement (the “Revolving Credit Facility”), with certain lenders party thereto from time to time (the “Lenders”), and Wells Fargo Bank, National Association, as administrative agent, for a revolving loan credit facility in the aggregate principal amount of $200.0 million. The Revolving Credit Facility is guaranteed by Oscar Management Corporation, a wholly owned subsidiary of the Company, and all of the Company's future direct and indirect subsidiaries (subject to certain permitted exceptions, including exceptions guarantees that would require material governmental consents or in respect of a joint venture) (the "Guarantors"). The Revolving Credit Facility is secured by substantially all of the Company’s and the Guarantors' assets (subject to certain exceptions). Proceeds are to be used solely for general corporate purposes of the Company. The Company is permitted to increase commitments under the Revolving Credit Facility by an aggregate amount not to exceed $50 million, subject to certain conditions. The Company may voluntarily prepay loans or reduce commitments under the Revolving Credit Facility, in whole or in part, subject to minimum amounts, with prior notice. The Revolving Credit Facility matures on February 21, 2024. Under the terms of the Revolving Credit Facility, borrowings under the Revolving Credit Facility bear interest at a rate equal to, at the Company's option, either (a) a rate per annum equal to an Adjusted LIBO Rate, plus an applicable margin of 4.50% (Adjusted London Interbank Offered Rate, or LIBO, is calculated based on one-, three- or six-month LIBO rates, or such other period as agreed by all relevant Lenders, which is determined by reference to ICE Benchmark Administration Limited, but not less than 1.00%), or (b) a rate per annum equal to the Alternate Base Rate, as defined in the Revolving Credit Facility, plus the applicable margin of 3.50% (the Alternate Base Rate is equal to the highest of (i) the prime rate, (ii) the federal funds effective rate plus 0.50%, and (iii) the Adjusted LIBO Rate based on a one-month interest period, plus 1.00%). The Revolving Credit Facility also includes a commitment fee of 0.50% for available but unborrowed amounts and other administrative fees that are payable quarterly. It also includes LIBO rate replacement provisions in the event LIBO rate becomes unavailable during the term of this facility. The Revolving Credit Facility is available until February 2024, provided the Company is in compliance with all covenants. Financial covenant requirements include maintaining minimum thresholds related to direct policy premiums and liquidity and a maximum combined ratio. As of March 31, 2021, there were no amounts outstanding under the Revolving Credit Facility. Warrants and Call Options In prior years, the Company issued several rounds of warrants to purchase preferred stock. Since the Company’s convertible preferred stock was classified outside of permanent equity, the warrants were accounted for as liabilities using the fair market value on the issuance date, with remeasurement required at each reporting period. During the three months ended March 31, 2021 and 2020, a gain (loss) on the fair value of warrant liabilities of $(12.9) million and $0.9 million, respectively, was recognized in general and administrative expenses in the consolidated statement of operations as a result of the changes in fair value of the warrant liabilities. The following table presents relevant information regarding outstanding warrants and call options: Warrant Type Issue Date Warrants Issued Issue Price Maximum No. of Preferred Stock Issuable Warrants Outstanding as of 12/31/20 Warrants Outstanding as of 3/31/21 Series AA Warrant 2013 629,152 $ 0.56 629,152 629,152 — Series A8 Warrant 2017 166,666 $ 6.75 166,666 166,666 — Series A9 Warrant 2018 416,666 $ 7.13 416,666 416,666 — Series A11 Call Options 2020 4,143,028 $ 6.02 4,143,028 12,732 — 1,225,216

CONVERTIBLE PREFERRED STOCK

CONVERTIBLE PREFERRED STOCK	3 Months Ended
	Mar. 31, 2021
Temporary Equity Disclosure [Abstract]
CONVERTIBLE PREFERRED STOCK	CONVERTIBLE PREFERRED STOCK In prior years, the Company issued several series of convertible preferred stock, collectively referred to as "Preferred Stock," that have been classified outside of stockholders' equity (deficit) on the consolidated balance sheet because the holders of such shares had liquidation rights that, in certain situations, were not solely within the control of the Company. In connection with the IPO, all convertible preferred stock outstanding as of December 31, 2020 were converted into shares of Series A and Series B common stock. Refer to Note 11 - Stockholders' Equity for more information. The table below presents relevant information relating to convertible preferred stock for the periods presented: December 31, 2020 March 31, 2021 Preferred Stock Preferred Stock Outstanding (pre-split) Preferred Stock Converted to Common Stock (Series A/B) (pre-split) Preferred Stock Outstanding A 41,913,800 (41,913,800) — A1 1,371,010 (1,371,010) — AA 22,379,980 (22,379,980) — AAA 36,109,790 (36,109,790) — A4 23,142,080 (23,142,080) — A5 29,189,760 (29,189,760) — A6 29,942,474 (29,942,474) — A7 6,265,845 (6,265,845) — A8 56,434,363 (56,434,363) — A9 23,177,793 (23,177,793) — AA-9 11,820,502 (11,820,502) — A10 53,877,952 (53,877,952) — A11 49,678,169 (49,678,169) — A12 15,600,784 (15,600,784) — Total 400,904,302 (400,904,302) —

STOCKHOLDERS' EQUITY

STOCKHOLDERS' EQUITY	3 Months Ended
	Mar. 31, 2021
Equity [Abstract]
STOCKHOLDERS' EQUITY	STOCKHOLDERS' EQUITY Initial Public Offering As described in Note 1 - Organization, in March 2021 the Company completed its IPO of 36,391,946 shares of Class A Common Stock at a par value of $0.00001 and a public offering price of $39.00 per share. The Company received aggregate net proceeds of $1.3 billion after deducting underwriting discounts and commissions of $71.0 million. The Company used a portion of the net proceeds of the IPO to repay in full outstanding borrowings, including fees and expenses, under the Term Loan Facility. Refer to Note 9 - Debt and Warrants. Reclassification and Stock Split Conversion of Preferred Stock and Series B Common Stock to Series A Common Stock In accordance with the terms and provisions of the Company’s Thirteenth Amended and Restated Certificate of Incorporation (the “Prior Certificate of Incorporation”), which was in effect immediately prior to the filing of the Amended and Restated Certificate of Incorporation, the holders of 402,192,500 shares (pre-split) of the Company’s convertible preferred stock effected a conversion of all shares of convertible preferred stock to 403,261,643 shares (pre-split) of Series A common stock, $0.00001 par value per share (the “Series A Common Stock”) (the “Preferred Stock Conversion”), and the holders of 9,360,800 shares (pre-split) of the Company’s Series B common stock, $0.00001 par value per share (the “Series B Common Stock”), effected a conversion of such shares of Series B Common Stock to 9,360,800 shares (pre-split) of the Company’s Series A common stock (the “Series B Conversion”), in each case effective as of the pricing of the IPO on March 2, 2021. Authorization of New Class of Shares and Conversion of Series A Common Stock and Stock Split In connection with the IPO, on March 3, 2021, the Company filed its Amended and Restated Certificate of Incorporation which, among other things, provides for: • the authorization of 825,000,000 shares of Class A Common Stock, 82,500,000 shares of Class B Common Stock, and 82,500,000 shares of preferred stock; • the reclassification of each share of Series A Common Stock (other than shares of Series A common stock held by Thrive Capital Partners II, L.P., Thrive Capital Partners III, L.P., Thrive Capital Partners V, L.P., Thrive Capital Partners VI Growth, L.P., Claremount TW, L.P., Claremount VI Associates, L.P. and Claremount V Associates, L.P. (the “Thrive Series A Common Stock”)) issued and outstanding or held in treasury immediately prior to the filing of the Amended and Restated Certificate of Incorporation into one share of Class A Common Stock (the “Class A Reclassification”); • the reclassification of each share of Series B Common Stock issued and outstanding or held in treasury immediately prior to the filing of the Amended and Restated Certificate of Incorporation and each share of Thrive Series A Common Stock into one share of Class B common stock (the “Class B Reclassification” and, together with the Class A Reclassification, the “Reclassification”); • the reclassification of each three shares of Class A Common Stock issued and outstanding or held in treasury immediately following the Class A Reclassification into one validly issued, fully paid and non-assessable share of Class A Common Stock (the “Class A Stock Split”); and • the reclassification of each three shares of Class B Common Stock issued and outstanding or held in treasury immediately following the Class B Reclassification into one validly issued, fully paid and non-assessable share of Class B Common Stock (the “Class B Stock Split” and, together with the Class A Stock Split, the “Stock Split”). No fractional shares of Class A Common Stock or Class B Common Stock were delivered as a result of the Stock Split. Summary of IPO Share Transactions As a result of the IPO, the Preferred Stock Conversion, the Series B Conversion, the Reclassification, and the Stock Split described above, the following activity occurred: • 402,192,500 shares (pre-split) of convertible preferred stock were converted into 403,261,643 shares (pre-split) of Series A Common Stock; • 9,360,800 shares (pre-split) of Series B Common Stock were converted into 9,360,800 shares (pre-split) of Series A Common Stock; • 398,283,107 shares (pre-split) of Series A Common Stock were reclassified as 398,283,107 shares (pre-split) of Class A Common Stock; • 60,127,163 shares (pre-split) of Series B Common Stock were reclassified as 60,127,163 shares (pre-split) of Class B Common Stock; • 45,879,623 shares (pre-split) of Series A Common Stock were reclassified as 45,879,623 shares (pre-split) of Class B Common Stock; • 398,283,107 shares (pre-split) of Class A Common Stock were reclassified as 132,760,639 shares (post-split) of Class A Common Stock; • 106,006,786 shares (pre-split) of Class B Common Stock were reclassified as 35,335,579 shares (post-split) of Class B Common Stock; • 219,772 shares (post-split) of Class B Common Stock converted to 219,772 shares (post-split) of Class A Common Stock in connection with a secondary sale in the IPO; and • the Company issued 36,391,946 shares (post-split) of Class A Common Stock at a par value of $0.00001 and a public offering price of $39.00 per share. Common Stock The rights of the holders of Class A Common Stock and Class B Common Stock are identical, except with respect to voting, conversion, and transfer rights. Voting Rights Holders of the Company’s Class A Common Stock are entitled to one vote for each share held on all matters submitted to a vote of stockholders, and holders of the Company’s Class B Common Stock are entitled to 20 votes for each share held on all matters submitted to a vote of stockholders. The holders of the Company’s Class A Common Stock and Class B Common Stock will vote together as a single class, unless otherwise required by law or under the Amended and Restated Certificate of Incorporation. Conversion and Transfer Each outstanding share of Class B Common Stock is convertible at any time at the option of the holder into one share of Class A Common Stock. Each share of Class B Common Stock will convert automatically into one share of Class A Common Stock upon any transfer, except for certain permitted transfers described in the Amended and Restated Certificate of Incorporation. All outstanding shares of Class B Common Stock will automatically convert into shares of Class A Common Stock on a one-for-one basis upon the date that is the earlier of (i) the transfer of Class B common stock to a person or entity that is not in the transferor’s permitted ownership group, as described in the Amended and Restated Certificate of Incorporation, (ii) March 2, 2028, or (iii) upon the occurrence of certain other events as described in the Amended and Restated Certificate of Incorporation. Dividends

STOCK-BASED COMPENSATION

STOCK-BASED COMPENSATION	3 Months Ended
	Mar. 31, 2021
Share-based Payment Arrangement [Abstract]
STOCK-BASED COMPENSATION	STOCK-BASED COMPENSATION 2012 Incentive Award Plan Prior to the IPO, the Company maintained the 2012 Stock Plan (the “2012 Plan”), which provided for the grant of stock options (including ISOs and NSOs), common stock of the Company, stock payments and restricted stock units ("RSUs"). The 2012 Plan was initially adopted on December 6, 2012 and most recently amended and restated in October 2020. The 2012 Plan was terminated upon the effectiveness of the 2021 Incentive Award Plan in March 2021, and no further awards will be made under the 2012 Plan. 2021 Incentive Award Plan In March 2021, the Company’s board of directors adopted the 2021 Incentive Award Plan, (the “2021 Plan”), which provides for the grant of stock options, stock appreciation rights (“SARs”), restricted stock, RSUs, performance awards, dividend equivalents and other stock or cash awards to employees, consultants and non-employee directors. Stock-Based Compensation Expense For the three months ended March 31, 2021, $19.1 million of stock-based compensation expense was recognized, of which $9.4 million was recognized within general and administrative expenses and $9.7 million was recognized within other insurance costs in the statement of operations. For the three months ended March 31, 2020, $8.1 million of stock-based compensation expense was recognized, of which $4.0 million was recognized within general and administrative expenses and $4.1 million was recognized within other insurance costs in the statement of operations. These amounts include the effects of award modifications for the extension of post-employment exercise periods, which result in the recognition of additional stock-based compensation expense. Stock Options Stock options granted under the 2012 Plan and 2021 Plan include ISO and NSO options, generally have a maximum contractual term of 10 years and typically vest over a four-year period. The following table summarizes the stock option award activity under the 2012 Plan and 2021 Plan for the three months ended March 31, 2021: March 31, 2021 Number of Options Weighted Average Exercise Price Weighted Average Contractual Life (in years) Aggregate Intrinsic Value (in thousands, except exercise price) Balance - December 31, 2020 41,115,486 $ 9.19 7.59 $ 279,477 Options granted 1,245,593 $ 27.03 Options exercised (4,306,297) $ 6.92 $ 91,855 Options canceled (400,101) $ 15.86 Balance - March 31, 2021 37,654,681 $ 9.95 7.56 $ 642,569 Options Exercisable at March 31, 2021 22,887,959 $ 8.25 6.51 $ 426,382 Determination of Fair Value of Stock Options The fair value of stock option awards granted is estimated on the grant date using the Black-Scholes option pricing model. The weighted average grant date fair value of options granted during the three months ended March 31, 2021 was $10.42. The table below summarizes the assumptions used: March 31, 2021 Term in years 5.99 Dividend rate — % Risk free rate of return 0.75 % Volatility 39.40 % Compensation Expense – Stock Options During the three months ended March 31, 2021 and 2020, the Company recorded compensation expense of $13.2 million and $7.5 million, respectively. The amount of unrecognized compensation expense for stock options is $80.0 million, which is expected to be recognized over a weighted-average period of 2.9 years. Restricted Stock Units (“RSUs”) RSUs represent the right to receive shares of the Company’s Class A Common Stock at a specified date in the future and typically have a vesting period of one The following table summarizes RSU award activity for the three months ended March 31, 2021: RSU Number of Shares Weighted Average Grant Date Fair Value Unvested RSUs at December 31, 2020 1,555,666 $ 15.82 RSUs granted 908,344 $ 28.38 RSUs canceled (153) $ 31.00 Unvested RSUs at March 31, 2021 2,463,857 $ 20.45 Determination of Fair Value of RSUs The fair value of RSUs granted is determined on the grant date based on the fair value of the Company's common stock. Compensation Expense – RSUs During the three months ended March 31, 2021, the Company recorded compensation expense of $4.3 million. The amount of unrecognized compensation expense for RSUs is $45.6 million, which is expected to be recognized over a weighted-average period of 3.2 years. Performance-based Restricted Stock Units (“PSUs”) In February 2021, a special committee comprised of independent members of the Company’s board of directors approved the grant of PSUs to the Company’s co-founders (the "Co-Founders"), which are referred to as the “Founders Awards.” The Founders Awards cover 6,344,779 shares of Class A Common Stock (cumulative) and will be eligible to vest based on the achievement of pre-determined stock price goals over a seven-year period. The Founders Awards are intended to retain and incentivize the Co-Founders to lead the Company to sustained, long-term financial and operational performance. The following table summarizes PSU award activity for the three months ended March 31, 2021: PSU Number of Shares Weighted Average Grant Date Fair Value Unvested PSUs at December 31, 2020 — $ — PSUs granted 6,344,779 $ 14.22 PSUs canceled — $ — Unvested PSUs at March 31, 2021 6,344,779 $ 14.22 Determination of Fair Value of PSUs The weighted average grant date fair value of the PSUs is $14.22, which was estimated on the grant date using a Monte Carlo simulation. The table below summarizes the assumptions used: Grant date stock price $ 39.00 Term in years 7.0 Expected volatility 45 % Risk-free rate 1.14 % Dividend yield — % Compensation Expense – PSUs During the three months ended March 31, 2021, the Company recorded compensation expense of $1.6 million. The amount of unrecognized compensation expense for PSUs is $88.7 million, which is expected to be recognized over a weighted-average period of 4.5 years.

EARNINGS (LOSS) PER SHARE

EARNINGS (LOSS) PER SHARE	3 Months Ended
	Mar. 31, 2021
Earnings Per Share [Abstract]
EARNINGS (LOSS) PER SHARE	EARNINGS (LOSS) PER SHARE Earnings (loss) per share ("EPS") is calculated using the two-class method, which is an earnings allocation model that treats participating securities as having rights to earnings that otherwise would have been available to common stockholders. Under the two-class method, earnings for the period are required to be allocated between common stock and participating securities based upon their respective rights to receive distributed and undistributed earnings. For EPS computation purposes, the Company's Class A and Class B common stock are considered one single class of common stock because both classes have the same dividend and liquidation rights. The following table presents the computation of basic and diluted earnings per share: Three Months Ended March 31, 2021 March 31, 2020 (in thousands, except share and per share data) Numerator : Net loss attributable to common stockholders $ (87,371) $ (96,879) Denominator : Weighted average common shares outstanding, basic and diluted 88,865,726 28,874,520 Net loss per share, basic and diluted $ (0.98) $ (3.36) In periods when the Company is in a net loss position, dilutive securities are excluded from the computation of diluted earnings per share because their inclusion would have an anti-dilutive effect. Thus, basic net loss per share is the same as diluted net loss per share.

VARIABLE INTEREST ENTITIES

VARIABLE INTEREST ENTITIES	3 Months Ended
	Mar. 31, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
VARIABLE INTEREST ENTITIES	VARIABLE INTEREST ENTITIES In the normal course of business, the Company enters into business arrangements with integrated health systems, which include multiple hospitals, health care centers, large independent practice associations, physicians and ancillary providers licensed to provide health care services in the states of Ohio and New York, and several medical professional corporations (collectively, the "Professional Corporations") that employ health care providers to deliver telemedical healthcare services to its covered member population in various states. The Company evaluated its involvement with these entities and considered whether it has (i) the power to direct the activities of the VIE that most significantly impact the economic performance of the VIE and (ii) the obligation to absorb losses of, or the right to receive benefits from, the VIE that could be potentially significant to the VIE. The Company has determined that consolidation was required because these entities are deemed VIEs and the Company is considered to be the primary beneficiary of these entities. Integrated Health Systems The Company has arrangements with integrated health systems through its wholly-owned subsidiaries, Oscar Insurance Corporation of Ohio and Oscar Health Plan of New York, which are consolidated into the Company’s financial results pursuant to the guidance regarding Variable Interest Entities. For the Company’s arrangements with integrated health systems, the Company shares 50% of the underwriting risks through shared savings and 50% of net income. Payments to the healthcare networks are expensed and are included in claims incurred, net in the consolidated statement of operations. For the three months ended March 31, 2021, the Company incurred $0.9 million of expenses through shared savings arrangements. The Company did not incur any expenses through shared services arrangements for the three months ended March 31, 2020. Professional Corporations The Company has a series of contractual relationships with several medical professional corporations and has determined it has a controlling financial interest in them because, as part of its arrangement, it has guaranteed their debt, and the equity at risk is insufficient to finance their activities without additional subordinated financial support from the Company. As of March 31, 2021, the collective assets and liabilities of the professional corporations were $1.9 million and $9.8 million, respectively. As of December 31, 2020, the collective assets and liabilities of the professional corporations were $1.9 million and $7.6 million, respectively. For the three months ended March 31, 2021, the collective revenues and operating expenses of the professional corporations were $2.0 million and $4.2 million, respectively. For the three months ended March 31, 2020, the collective revenues and operating expenses of the professional corporations were $1.2 million and $2.8 million, respectively.

COMMITMENTS AND CONTINGENCIES

COMMITMENTS AND CONTINGENCIES	3 Months Ended
	Mar. 31, 2021
Commitments and Contingencies Disclosure [Abstract]
COMMITMENTS AND CONTINGENCIES	COMMITMENTS AND CONTINGENCIES In the ordinary course of business, the Company is frequently made party to a variety of legal actions and regulatory inquiries, including class actions and suits brought by members, care providers, customers and regulators, relating to the Company’s businesses, including management and administration of health benefit plans and other services. These matters include employment and contract claims and claims related to health care benefits coverage and other business practices. The Company records liabilities for its estimates of probable costs resulting from these matters where appropriate. Estimates of costs resulting from legal and regulatory matters involving the Company are inherently difficult to predict, particularly where the matters: involve indeterminate claims for monetary damages or may involve fines, penalties or punitive damages; present novel legal theories or represent a shift in regulatory policy; involve a large number of claimants or regulatory bodies; are in the early stages of the proceedings; or could result in a change in business practices. Accordingly, the Company is often unable to estimate the losses or ranges of losses for those matters where there is a reasonable possibility or it is probable that a loss may be incurred, the ultimate settlement of which could be material.

SUBSEQUENT EVENTS

SUBSEQUENT EVENTS	3 Months Ended
	Mar. 31, 2021
Subsequent Events [Abstract]
SUBSEQUENT EVENTS	SUBSEQUENT EVENTSOn May 12, 2021, the Company terminated its 2021 quota share arrangements with Canada Life Assurance Company (“Canada Life”), effective as of April 1, 2021. In connection with the termination, the Company will pay amounts due under the agreements for the three months ended March 31, 2021. During the three months ended March 31, 2021, the Company ceded approximately 10% of premiums before ceded reinsurance to Canada Life as part of its quota share reinsurance program.

ORGANIZATION (Policies)

ORGANIZATION (Policies)	3 Months Ended
	Mar. 31, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation	Basis of Presentation The accompanying interim condensed consolidated financial statements of the Company are unaudited. These interim unaudited condensed consolidated financial statements have been prepared in accordance with U.S. GAAP, and the applicable rules and regulations of the Securities and Exchange Commission ("SEC") for interim financial information. As such, these financial statements do not include all information and footnotes required by U.S. GAAP for complete financial statements.
Use of Estimates	Use of Estimates The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the amounts reported in the unaudited consolidated financial statements and accompanying notes. Significant estimates inherent in the preparation of the accompanying unaudited consolidated financial statements include healthcare costs incurred but not yet reported (“IBNR”), reinsurance, premium deficiency reserve (“PDR”), risk adjustment, stock-based compensation, premium receivable allowance and income taxes. Estimates are based on past experience and other considerations reasonable under the circumstances. Actual results may differ materially from these estimates. Additionally, the full extent to which the outbreak of COVID-19 could impact the Company’s business, results of operations and financial condition is still unknown and will depend on future developments, which are highly uncertain and cannot be predicted. However, the Company has made accounting estimates based on the facts and circumstances available as of the reporting date. The Company has not currently experienced significant negative impact to its operations, liquidity or capital resources as a result of the COVID-19 pandemic.
Accounting Pronouncements - Recently Adopted and Not Yet Adopted	Accounting Pronouncements - Recently Adopted In August 2018, the Financial Accounting Standards Board ("FASB") issued ASU 2018-13, “Fair Value Measurement (Topic 820): Disclosure Framework-Changes to the Disclosure Requirements for Fair Value Measurement,” (“ASU 2018-13”). The amendments in ASU 2018-13 eliminate, add, and modify certain disclosure requirements for fair value measurements. The amendments are effective for interim and annual periods beginning after December 15, 2019, with early adoption permitted for either the entirety of ASU 2018-13 or only the provisions that eliminate or modify disclosure requirements. The Company adopted the standard effective January 1, 2020. The adoption of this standard did not have a material impact on the Company's consolidated financial statements. In November 2018, the FASB issued ASU 2018-18, “Collaborative Arrangements (Topic 808): Clarifying the Interaction Between Topic 808 and Topic 606” (“ASU 2018-18”). The amendments in ASU 2018-18 clarify that certain transactions between collaborative arrangement participants should be accounted for as revenue under ASC 606 when the collaborative arrangement participant is a customer in the context of a unit of account. The amendments under ASU 2018-18 are effective for interim and annual fiscal periods beginning after December 15, 2019, with early adoption permitted. The amendments in ASU 2018-18 should be applied retrospectively to the date of initial application of ASC 606. The Company adopted the standard effective January 1, 2020. The adoption of this standard did not have a material impact on the Company's consolidated financial statements. Accounting Pronouncements - Not Yet Adopted From time to time, new accounting pronouncements are issued by the FASB or other standard setting bodies that the Company adopts as of the specified effective date. 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 it (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, these financial statements may not be comparable to companies that comply with the new or revised accounting pronouncements as of public company effective dates. In February 2016, the (FASB) issued (ASU) 2016- 02, “Leases (Topic 842)” (ASU 2016-02). Under ASU 2016-02, an entity will be required to recognize assets and liabilities for the rights and obligations created by leases on the entity’s balance sheet for both finance and operating leases. For leases with a term of 12 months or less, an entity can elect to not recognize lease assets and lease liabilities and expense the lease over a straight-line basis for the term of the lease. ASU 2016-02 will require new disclosures that depict the amount, timing, and uncertainty of cash flows pertaining to an entity’s leases. Companies are required to adopt the new standard using a modified retrospective approach for annual and interim periods beginning after December 15, 2018. In June 2020, the FASB issued guidance extending the effective date for all entities for which these standards are either currently or imminently effective. This guidance is effective for the Company for annual periods beginning after December 15, 2021. Early adoption is permitted. The Company is currently evaluating the effect that the adoption of ASU 2016-02 will have on its consolidated financial statements. In June 2016, the FASB issued ASU 2016-13, " Financial Instruments - Credit Losses (Topic 326) " (“ASU 2016-13”), which requires entities to use a current expected credit loss model, which is a new impairment model based on expected losses rather than incurred losses. Under this model, an entity would recognize an impairment allowance equal to its current estimate of all contractual cash flows that the entity does not expect to collect from financial assets measured at amortized cost. The entity's estimate would consider relevant information about past events, current conditions, and reasonable and supportable forecasts, which will result in recognition of lifetime expected credit losses upon loan origination. In November 2018, the FASB issued ASU No. 2018-19, “ Codification Improvements to Topic 326, Financial Instruments-Credit Losses ,” which narrowed the scope and changed the effective date for non-public entities for ASU 2016-13. The FASB subsequently issued supplemental guidance within ASU No. 2019-05, “ Financial Instruments-Credit Losses (Topic 326): Targeted Transition Relief ” (‘‘ASU 2019-05’’). ASU 2019-05 provides an option to irrevocably elect the fair value option for certain financial assets previously measured at amortized cost basis. In November 2019, the FASB issued ASU 2019-11, “ Codification Improvements to Topic 326, Financial Instruments - Credit Losses ” (“ASU 2019-11”) guidance extending the effective date for all non-public business entities. In May 2019, the FASB issued ASU 2019-05, “ Financial Instruments - Credit Losses (Topic 326): Targeted Transition Relief .” In April 2019, the FASB issued ASU 2019-04, “ Codification Improvements to Topic 326, Financial Instruments - Credit Losses, Topic 815, Derivatives and Hedging, and Topic 825, Financial Instruments. ” These updates provide an option to irrevocably elect to measure certain individual financial assets at fair value instead of amortized cost and provide additional clarification and implementation guidance on certain aspects of the previously issued ASU 2016-13 and have the same effective date and transition requirements as ASU 2016-13. The effect of a prospective transition approach is to maintain the same amortized cost basis before and after the date of adoption. ASU 2016-13 is effective for the Company for annual periods beginning after December 15, 2022. Early adoption is permitted. The Company is currently assessing the effect that the adoption of ASU 2016-13 will have on its consolidated financial statements. In December 2019, the FASB issued ASU 2019-12, “Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes” (“ASU 2019-12”). The amendments in ASU 2019-12 remove certain exceptions to the general principles in ASC Topic 740. The amendments also clarify and amend existing guidance to improve consistent application. The amendments are effective for the Company’s annual reporting periods beginning after December 15, 2021. Early adoption is permitted. The transition method (retrospective, modified retrospective, or prospective basis) related to the amendments depends on the applicable guidance, and all amendments for which there is no transition guidance specified are to be applied on a prospective basis. The Company is currently evaluating the effects the adoption of ASU 2019-12 will have on its consolidated financial statements.

PREMIUMS EARNED (Tables)

PREMIUMS EARNED (Tables)	3 Months Ended
	Mar. 31, 2021
Insurance [Abstract]
Schedule of premiums earned	Three Months Ended March 31, 2021 March 31, 2020 Premiums Earned: (in thousands) Direct policy premiums $ 820,814 $ 572,011 Assumed premiums 2,411 — Direct and assumed premiums 823,225 572,011 Risk adjustment (213,126) (147,563) Premiums before ceded reinsurance 610,099 424,448 Reinsurance premiums ceded (241,562) (339,229) Total premiums earned $ 368,537 $ 85,219 The composition of total reinsurance premiums ceded and reinsurance premiums assumed, which are included as components of total earned premiums in the consolidated statement of operations, is as follows: Three Months Ended March 31, 2021 March 31, 2020 (In thousands) Reinsurance premiums ceded, gross $ (264,787) $ (357,710) Experience refunds 23,225 18,481 Reinsurance premiums ceded (241,562) (339,229) Reinsurance premiums assumed 2,411 — Total reinsurance premiums ceded and assumed $ (239,151) $ (339,229) The Company records claims expense net of reinsurance recoveries. The following table reconciles the total claims expense to the net claims expense as presented in the consolidated statement of operations: Three Months Ended March 31, 2021 March 31, 2020 (In thousands) Direct claims incurred $ 457,219 $ 345,508 Ceded reinsurance claims (190,948) (261,290) Assumed reinsurance claims 1,777 (2) Total claims incurred, net $ 268,048 $ 84,216 The Company records selling, general and administrative expenses net of ceding commissions. The following table reconciles total other insurance costs to the amount presented in the consolidated statement of operations: Three Months Ended March 31, 2021 March 31, 2020 (In thousands) Other insurance costs, gross $ 99,143 $ 75,930 Ceding commissions (19,306) (35,026) Other insurance costs, net $ 79,837 $ 40,904 The Company records reinsurance recoverables as “balances due from reinsurance programs” within current assets on its consolidated balance sheets. The composition of the reinsurance recoverables balance is as follows: March 31, 2021 December 31, 2020 (In thousands) Ceded reinsurance claim recoverables $ 307,943 $ 435,331 Reinsurance ceding commissions 27,469 41,586 Experience refunds on reinsurance agreements 18,584 102,476 Balances due from reinsurance programs $ 353,996 $ 579,393

REINSURANCE (Tables)

REINSURANCE (Tables)	3 Months Ended
	Mar. 31, 2021
Insurance [Abstract]
Schedule of premiums earned	Three Months Ended March 31, 2021 March 31, 2020 Premiums Earned: (in thousands) Direct policy premiums $ 820,814 $ 572,011 Assumed premiums 2,411 — Direct and assumed premiums 823,225 572,011 Risk adjustment (213,126) (147,563) Premiums before ceded reinsurance 610,099 424,448 Reinsurance premiums ceded (241,562) (339,229) Total premiums earned $ 368,537 $ 85,219 The composition of total reinsurance premiums ceded and reinsurance premiums assumed, which are included as components of total earned premiums in the consolidated statement of operations, is as follows: Three Months Ended March 31, 2021 March 31, 2020 (In thousands) Reinsurance premiums ceded, gross $ (264,787) $ (357,710) Experience refunds 23,225 18,481 Reinsurance premiums ceded (241,562) (339,229) Reinsurance premiums assumed 2,411 — Total reinsurance premiums ceded and assumed $ (239,151) $ (339,229) The Company records claims expense net of reinsurance recoveries. The following table reconciles the total claims expense to the net claims expense as presented in the consolidated statement of operations: Three Months Ended March 31, 2021 March 31, 2020 (In thousands) Direct claims incurred $ 457,219 $ 345,508 Ceded reinsurance claims (190,948) (261,290) Assumed reinsurance claims 1,777 (2) Total claims incurred, net $ 268,048 $ 84,216 The Company records selling, general and administrative expenses net of ceding commissions. The following table reconciles total other insurance costs to the amount presented in the consolidated statement of operations: Three Months Ended March 31, 2021 March 31, 2020 (In thousands) Other insurance costs, gross $ 99,143 $ 75,930 Ceding commissions (19,306) (35,026) Other insurance costs, net $ 79,837 $ 40,904 The Company records reinsurance recoverables as “balances due from reinsurance programs” within current assets on its consolidated balance sheets. The composition of the reinsurance recoverables balance is as follows: March 31, 2021 December 31, 2020 (In thousands) Ceded reinsurance claim recoverables $ 307,943 $ 435,331 Reinsurance ceding commissions 27,469 41,586 Experience refunds on reinsurance agreements 18,584 102,476 Balances due from reinsurance programs $ 353,996 $ 579,393

RESTRICTED CASH AND RESTRICTE_2

RESTRICTED CASH AND RESTRICTED DEPOSITS (Tables)	3 Months Ended
	Mar. 31, 2021
Cash and Cash Equivalents [Abstract]
Schedule of restricted deposits	March 31, 2021 December 31, 2020 (in thousands) Restricted cash and cash equivalents $ 16,779 $ 16,779 Restricted investments 9,670 9,699 Restricted Deposits, as reported on the balance sheet $ 26,449 $ 26,478

INVESTMENTS (Tables)

INVESTMENTS (Tables)	3 Months Ended
	Mar. 31, 2021
Investments, Debt and Equity Securities [Abstract]
Summary of investments	The following tables provide summaries of investments by major security type: March 31, 2021 Amortized Cost Unrealized Gains Unrealized Losses Fair Value (in thousands) U.S. treasury and agency securities $ 529,333 $ 476 $ (30) $ 529,779 Corporate notes 177,190 165 (95) 177,260 Certificate of deposit 2,370 — — 2,370 Commercial paper 6,044 — — 6,044 Municipalities 3,160 — — 3,160 Total $ 718,097 $ 641 $ (125) $ 718,613 December 31, 2020 Amortized Cost Unrealized Gains Unrealized Losses Fair Value (in thousands) U.S. treasury and agency securities $ 523,809 $ 562 $ (2) $ 524,369 Corporate notes 159,461 262 (58) 159,665 Certificate of deposit 7,043 — — 7,043 Commercial paper 1,050 — — 1,050 Total $ 691,363 $ 824 $ (60) $ 692,127
Summary of investments in a gross unrealized loss position	The current securities that mature within one year or less in a gross unrealized loss position are as follows: March 31, 2021 Number of Securities Fair Value Gross (in thousands) Investments twelve months or less: Corporate notes 67 37,238 (5) Total 67 $ 37,238 $ (5) December 31, 2020 Number of Securities Fair Value Gross (in thousands) Investments twelve months or less: U.S. treasury and agency securities 51 $ 339,014 $ (2) Corporate notes 40 19,280 (3) Total 91 $ 358,294 $ (5) Long-term securities that mature over twelve months or more in a gross unrealized loss position are as follows: March 31, 2021 Number of Securities Fair Value Gross (in thousands) Investments over twelve months: U.S. treasury and agency securities 33 $ 186,160 $ (30) Corporate notes 192 140,021 (90) Total 225 $ 326,181 $ (120) December 31, 2020 Number of Securities Fair Value Gross (in thousands) Investments over twelve months: Corporate notes 189 140,384 (55) Total 189 $ 140,384 $ (55)
Summary of investment income	Net investment income was attributable to the following: Three Months Ended March 31, 2021 March 31, 2020 (in thousands) Interest income $ 1,345 $ 2,385 Investment discount amortization net of premium accretion (1,074) (155) Net realized gain 113 654 Total $ 384 $ 2,884

FAIR VALUE (Tables)

FAIR VALUE (Tables)	3 Months Ended
	Mar. 31, 2021
Fair Value Disclosures [Abstract]
Schedule of assets and liabilities measured on recurring basis	Assets and liabilities measured at fair value on recurring basis are as follows: March 31, 2021 (Level 1) (Level 2) (Level 3) Total Fair Value Measurement (in thousands) Investments U.S. treasury and agency securities $ — $ 529,779 $ — $ 529,779 Corporate notes — 177,259 — 177,259 Commercial paper — 6,044 — 6,044 Certificate of deposit — 2,370 — 2,370 Municipalities — 3,160 — 3,160 Total $ — $ 718,613 $ — $ 718,613 December 31, 2020 (Level 1) (Level 2) (Level 3) Total Fair Value Measurement (in thousands) Investments U.S. treasury and agency securities $ — $ 524,369 $ — $ 524,369 Corporate notes — 159,665 — 159,665 Commercial paper — 7,043 — 7,043 Certificate of deposit — 1,050 — 1,050 Total $ — $ 692,127 $ — $ 692,127 Warrant liabilities $ — $ — $ 15,005 $ 15,005
Reconciliation of derivative liabilities measured on recurring basis	The table below presents changes in the fair value of the Company’s Level 3 warrant liabilities as March 31, 2021 and December 31, 2020 as follows: March 31, 2021 December 31, 2020 (in thousands) Beginning balance $ 15,005 $ 8,819 Vesting of warrants — 392 Change in fair value 13,243 4,709 Preferred Stock Series A11 call options issued — 13,488 Preferred Stock Series A11 call options exercised (70) (12,403) Preferred Stock Series AA, A8, and A9 exercised (28,178) — Ending balance $ — $ 15,005

BENEFITS PAYABLE (Tables)

BENEFITS PAYABLE (Tables)	3 Months Ended
	Mar. 31, 2021
Insurance [Abstract]
Schedule of Liability for Unpaid Claims and Claims Adjustment Expense	The following table provides a rollforward of the Company’s beginning and ending benefits payable and claims adjustment expenses ("CAE") payable balances for the three months ended March 31, 2021 and 2020: As of March 31, 2021 Benefits Payable Unallocated Claims Total (in thousands) Benefits payable, beginning of the period $ 311,914 $ 5,509 $ 317,424 Less: Reinsurance recoverable 132,658 — 132,658 Benefits payable, beginning of the period, net $ 179,256 $ 5,509 $ 184,766 Claims incurred and CAE Current year $ 273,203 $ 16,262 $ 289,465 Prior years (5,155) — (5,155) Total claims incurred and CAE, net $ 268,048 $ 16,262 $ 284,310 Claims paid and CAE Current year $ 167,112 $ 9,943 $ 177,055 Prior years 2,219 5,509 7,728 Total claims and CAE paid, net $ 169,331 $ 15,452 $ 184,783 Benefits and CAE payable, end of period, net $ 277,974 $ 6,319 $ 284,293 Add: Reinsurance recoverable 80,092 — 80,092 Benefits and CAE payable, end of period $ 358,066 $ 6,319 $ 364,385 As of March 31, 2020 Benefits Payable Unallocated Claims Total (in thousands) Benefits payable, beginning of the period $ 156,557 $ 3,009 $ 159,567 Less: Reinsurance recoverable 76,184 — 76,184 Benefits payable, beginning of the period, net $ 80,373 $ 3,009 $ 83,383 Claims incurred and CAE Current year $ 82,573 $ 8,220 $ 90,794 Prior years 1,643 — 1,643 Total claims incurred and CAE, net $ 84,216 $ 8,220 $ 92,437 Claims paid and CAE Current year $ 44,873 $ 3,892 $ 48,765 Prior years 44,030 3,009 47,039 Total claims and CAE paid, net $ 88,903 $ 6,901 $ 95,804 Benefits and CAE payable, end of period, net $ 75,687 $ 4,328 $ 80,016 Add: Reinsurance recoverable 177,293 — 177,293 Benefits and CAE payable, end of period $ 252,980 $ 4,328 $ 257,309

DEBT AND WARRANTS (Tables)

DEBT AND WARRANTS (Tables)	3 Months Ended
	Mar. 31, 2021
Debt Disclosure [Abstract]
Schedule of outstanding warrants	The following table presents relevant information regarding outstanding warrants and call options: Warrant Type Issue Date Warrants Issued Issue Price Maximum No. of Preferred Stock Issuable Warrants Outstanding as of 12/31/20 Warrants Outstanding as of 3/31/21 Series AA Warrant 2013 629,152 $ 0.56 629,152 629,152 — Series A8 Warrant 2017 166,666 $ 6.75 166,666 166,666 — Series A9 Warrant 2018 416,666 $ 7.13 416,666 416,666 — Series A11 Call Options 2020 4,143,028 $ 6.02 4,143,028 12,732 — 1,225,216

CONVERTIBLE PREFERRED STOCK (Ta

CONVERTIBLE PREFERRED STOCK (Tables)	3 Months Ended
	Mar. 31, 2021
Temporary Equity Disclosure [Abstract]
Schedule of temporary equity	The table below presents relevant information relating to convertible preferred stock for the periods presented: December 31, 2020 March 31, 2021 Preferred Stock Preferred Stock Outstanding (pre-split) Preferred Stock Converted to Common Stock (Series A/B) (pre-split) Preferred Stock Outstanding A 41,913,800 (41,913,800) — A1 1,371,010 (1,371,010) — AA 22,379,980 (22,379,980) — AAA 36,109,790 (36,109,790) — A4 23,142,080 (23,142,080) — A5 29,189,760 (29,189,760) — A6 29,942,474 (29,942,474) — A7 6,265,845 (6,265,845) — A8 56,434,363 (56,434,363) — A9 23,177,793 (23,177,793) — AA-9 11,820,502 (11,820,502) — A10 53,877,952 (53,877,952) — A11 49,678,169 (49,678,169) — A12 15,600,784 (15,600,784) — Total 400,904,302 (400,904,302) —

STOCK-BASED COMPENSATION (Table

STOCK-BASED COMPENSATION (Tables)	3 Months Ended
	Mar. 31, 2021
Share-based Payment Arrangement [Abstract]
Summary of stock option award activity	The following table summarizes the stock option award activity under the 2012 Plan and 2021 Plan for the three months ended March 31, 2021: March 31, 2021 Number of Options Weighted Average Exercise Price Weighted Average Contractual Life (in years) Aggregate Intrinsic Value (in thousands, except exercise price) Balance - December 31, 2020 41,115,486 $ 9.19 7.59 $ 279,477 Options granted 1,245,593 $ 27.03 Options exercised (4,306,297) $ 6.92 $ 91,855 Options canceled (400,101) $ 15.86 Balance - March 31, 2021 37,654,681 $ 9.95 7.56 $ 642,569 Options Exercisable at March 31, 2021 22,887,959 $ 8.25 6.51 $ 426,382
Summary of stock option valuation assumptions	The table below summarizes the assumptions used: March 31, 2021 Term in years 5.99 Dividend rate — % Risk free rate of return 0.75 % Volatility 39.40 %
Summary of RSU activity	The following table summarizes RSU award activity for the three months ended March 31, 2021: RSU Number of Shares Weighted Average Grant Date Fair Value Unvested RSUs at December 31, 2020 1,555,666 $ 15.82 RSUs granted 908,344 $ 28.38 RSUs canceled (153) $ 31.00 Unvested RSUs at March 31, 2021 2,463,857 $ 20.45
Summary of PSU activity	The following table summarizes PSU award activity for the three months ended March 31, 2021: PSU Number of Shares Weighted Average Grant Date Fair Value Unvested PSUs at December 31, 2020 — $ — PSUs granted 6,344,779 $ 14.22 PSUs canceled — $ — Unvested PSUs at March 31, 2021 6,344,779 $ 14.22
Schedule of Share-based Payment Award, Equity Instruments Other than Options, Valuation Assumptions	The table below summarizes the assumptions used: Grant date stock price $ 39.00 Term in years 7.0 Expected volatility 45 % Risk-free rate 1.14 % Dividend yield — %

EARNINGS (LOSS) PER SHARE (Tabl

EARNINGS (LOSS) PER SHARE (Tables)	3 Months Ended
	Mar. 31, 2021
Earnings Per Share [Abstract]
Schedule of basic and diluted earnings per share	The following table presents the computation of basic and diluted earnings per share: Three Months Ended March 31, 2021 March 31, 2020 (in thousands, except share and per share data) Numerator : Net loss attributable to common stockholders $ (87,371) $ (96,879) Denominator : Weighted average common shares outstanding, basic and diluted 88,865,726 28,874,520 Net loss per share, basic and diluted $ (0.98) $ (3.36)

ORGANIZATION (Details)

ORGANIZATION (Details) $ / shares in Units, $ in Millions	Mar. 05, 2021USD ($)$ / sharesshares	Mar. 03, 2021$ / sharesshares	Mar. 31, 2021segment$ / sharesshares	Mar. 02, 2021shares
Subsidiary, Sale of Stock [Line Items]
Number of operating segments | segment			1
Stock split, conversion ratio		0.33
Conversion of stock, shares converted			400,904,302
IPO
Subsidiary, Sale of Stock [Line Items]
Sale of stock, net proceeds | $	$ 1,300
Sale of stock, discounts and commissions | $	$ 71
Treasury stock reclassified to Class A | Treasury Stock
Subsidiary, Sale of Stock [Line Items]
Conversion of stock, shares converted		943,800
Class A
Subsidiary, Sale of Stock [Line Items]
Common stock, par value (in dollars per share) | $ / shares		$ 0.00001	$ 0.00001
Stock split, conversion ratio		3
Common stock, shares outstanding		132,760,639	172,060,630	398,283,107
Class A | IPO
Subsidiary, Sale of Stock [Line Items]
Number of shares issued in transaction	36,391,946
Stock price (in dollars per share) | $ / shares	$ 39
Class A | Treasury stock reclassified to Class A
Subsidiary, Sale of Stock [Line Items]
Conversion of stock, shares issued		314,600
Class B
Subsidiary, Sale of Stock [Line Items]
Common stock, par value (in dollars per share) | $ / shares		$ 0.00001	$ 0.00001
Stock split, conversion ratio		3
Common stock, shares outstanding		35,335,579	35,115,807	106,006,786

PREMIUMS EARNED (Details)

PREMIUMS EARNED (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Effects of Reinsurance [Line Items]
Direct policy premiums	$ 820,814	$ 572,011
Assumed premiums	2,411	0
Direct and assumed premiums	823,225	572,011
Risk adjustment	(213,126)	(147,563)
Premiums before ceded reinsurance	610,099	424,448
Reinsurance premiums ceded	(241,562)	(339,229)
Premiums earned	368,537	85,219
CMS
Effects of Reinsurance [Line Items]
Direct policy premiums	$ 561,500	$ 335,600

REINSURANCE (Details)

REINSURANCE (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2021USD ($)entity	Mar. 31, 2020USD ($)	Dec. 31, 2020USD ($)
Insurance [Abstract]
Number of reinsurers | entity	2
Premiums Earned, Net [Abstract]
Reinsurance premiums ceded, gross	$ (264,787)	$ (357,710)
Experience refunds	23,225	18,481
Reinsurance premiums ceded	(241,562)	(339,229)
Assumed premiums	2,411	0
Total reinsurance premiums ceded and assumed	(239,151)	(339,229)
Policyholder Benefits and Claims Incurred, Net [Abstract]
Direct claims incurred	457,219	345,508
Ceded reinsurance claims	(190,948)	(261,290)
Assumed reinsurance claims	1,777	(2)
Total claims incurred, net	268,048	84,216
Other Insurance Cost, Net [Abstract]
Other insurance costs, gross	99,143	75,930
Ceding commissions	(19,306)	(35,026)
Other insurance costs, net	79,837	$ 40,904
Reinsurance Recoverables, Including Reinsurance Premium Paid [Abstract]
Ceded reinsurance claim recoverables	307,943		$ 435,331
Reinsurance ceding commissions	27,469		41,586
Experience refunds on reinsurance agreements	18,584		102,476
Balances due from reinsurance programs	$ 353,996		$ 579,393

RESTRICTED CASH AND RESTRICTE_3

RESTRICTED CASH AND RESTRICTED DEPOSITS (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Cash and Cash Equivalents [Abstract]
Restricted cash and cash equivalents	$ 16,779	$ 16,779
Restricted investments	9,670	9,699
Restricted Deposits, as reported on the balance sheet	$ 26,449	$ 26,478

INVESTMENTS - Summary of invest

INVESTMENTS - Summary of investments (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	$ 718,097	$ 691,363
Unrealized Gains	641	824
Unrealized Losses	(125)	(60)
Fair Value	718,613	692,127
U.S. treasury and agency securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	529,333	523,809
Unrealized Gains	476	562
Unrealized Losses	(30)	(2)
Fair Value	529,779	524,369
Corporate notes
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	177,190	159,461
Unrealized Gains	165	262
Unrealized Losses	(95)	(58)
Fair Value	177,260	159,665
Certificate of deposit
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	2,370	7,043
Unrealized Gains	0	0
Unrealized Losses	0	0
Fair Value	2,370	7,043
Commercial paper
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	6,044	1,050
Unrealized Gains	0	0
Unrealized Losses	0	0
Fair Value	6,044	$ 1,050
Municipalities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	3,160
Unrealized Gains	0
Unrealized Losses	0
Fair Value	$ 3,160

INVESTMENTS - Summary of inve_2

INVESTMENTS - Summary of investments in a gross unrealized loss position (Details) $ in Thousands	Mar. 31, 2021USD ($)security	Dec. 31, 2020USD ($)security
Investments twelve months or less:
Number of Securities | security	67	91
Fair Value	$ 37,238	$ 358,294
Gross Unrealized Losses	$ (5)	$ (5)
Investments over twelve months:
Number of Securities | security	225	189
Fair Value	$ 326,181	$ 140,384
Gross Unrealized Losses	$ (120)	$ (55)
U.S. treasury and agency securities
Investments twelve months or less:
Number of Securities | security		51
Fair Value		$ 339,014
Gross Unrealized Losses		$ (2)
Investments over twelve months:
Number of Securities | security	33
Fair Value	$ 186,160
Gross Unrealized Losses	$ (30)
Corporate notes
Investments twelve months or less:
Number of Securities | security	67	40
Fair Value	$ 37,238	$ 19,280
Gross Unrealized Losses	$ (5)	$ (3)
Investments over twelve months:
Number of Securities | security	192	189
Fair Value	$ 140,021	$ 140,384
Gross Unrealized Losses	$ (90)	$ (55)

INVESTMENTS - Summary of inve_3

INVESTMENTS - Summary of investment income (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Investments, Debt and Equity Securities [Abstract]
Interest income	$ 1,345	$ 2,385
Investment amortization, net of accretion	(1,074)	(155)
Net realized gain	113	654
Total	$ 384	$ 2,884

FAIR VALUE - Schedule of assets

FAIR VALUE - Schedule of assets and liabilities measured on recurring basis (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	$ 718,613	$ 692,127
Warrant liabilities	0	15,005
U.S. treasury and agency securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	529,779	524,369
Corporate notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	177,260	159,665
Commercial paper
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	6,044	1,050
Certificate of deposit
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	2,370	7,043
Municipalities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	3,160
Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	718,613	692,127
Warrant liabilities		15,005
Recurring | U.S. treasury and agency securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	529,779	524,369
Recurring | Corporate notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	177,259	159,665
Recurring | Commercial paper
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	6,044	7,043
Recurring | Certificate of deposit
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	2,370	1,050
Recurring | Municipalities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	3,160
(Level 1) | Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	0	0
Warrant liabilities		0
(Level 1) | Recurring | U.S. treasury and agency securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	0	0
(Level 1) | Recurring | Corporate notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	0	0
(Level 1) | Recurring | Commercial paper
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	0	0
(Level 1) | Recurring | Certificate of deposit
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	0	0
(Level 1) | Recurring | Municipalities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	0
(Level 2) | Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	718,613	692,127
Warrant liabilities		0
(Level 2) | Recurring | U.S. treasury and agency securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	529,779	524,369
(Level 2) | Recurring | Corporate notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	177,259	159,665
(Level 2) | Recurring | Commercial paper
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	6,044	7,043
(Level 2) | Recurring | Certificate of deposit
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	2,370	1,050
(Level 2) | Recurring | Municipalities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	3,160
(Level 3) | Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	0	0
Warrant liabilities		15,005
(Level 3) | Recurring | U.S. treasury and agency securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	0	0
(Level 3) | Recurring | Corporate notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	0	0
(Level 3) | Recurring | Commercial paper
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	0	0
(Level 3) | Recurring | Certificate of deposit
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	0	$ 0
(Level 3) | Recurring | Municipalities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	$ 0

FAIR VALUE - Reconciliation of

FAIR VALUE - Reconciliation of derivatives measured on recurring basis (Details) - Warrant - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	$ 15,005	$ 8,819
Vesting of warrants	0	392
Change in fair value	13,243	4,709
Preferred Stock Series A11 call options issued	0	13,488
Ending balance	0	15,005
Series A11
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Preferred Stock exercised	(70)	(12,403)
Series AA, A8, and A9 Preferred Stock
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Preferred Stock exercised	$ (28,178)	$ 0

BENEFITS PAYABLE (Details)

BENEFITS PAYABLE (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020	Dec. 31, 2019
Liability for Unpaid Claims and Claims Adjustment Expense [Roll Forward]
Benefits payable, beginning of period	$ 311,914	$ 156,557
CAE payable, beginning of the period	5,509	3,009
Benefits and CAE payable, beginning of period	364,385	257,309	$ 317,424	$ 159,567
Less: Reinsurance recoverable	132,658	76,184
Benefits payable, net reinsurance recoverable, beginning of period	179,256	80,373
Benefits and CAE payable, net, beginning of period	184,766	83,383
Benefits Payable
Current year	273,203	82,573
Prior years	(5,155)	1,643
Claims incurred	268,048	84,216
Unallocated Claims Adjustment Expense
Current year	16,262	8,220
Prior years	0	0
Claims adjustment expense	16,262	8,220
Total
Current year	289,465	90,794
Prior years	(5,155)	1,643
Total claims incurred and CAE, net	284,310	92,437
Benefits Payable
Current year	167,112	44,873
Prior years	2,219	44,030
Claims paid	169,331	88,903
Unallocated Claims Adjustment Expense
Current year	9,943	3,892
Prior years	5,509	3,009
CAE paid	15,452	6,901
Total
Current year	177,055	48,765
Prior years	7,728	47,039
Total claims and CAE paid, net	184,783	95,804
Benefits payable, net reinsurance recoverable, end of period	277,974	75,687
CAE payable, end of the period	6,319	4,328
Benefits and CAE payable, net, end of period	284,293	80,016
Add: Reinsurance recoverable	80,092	177,293
Benefits payable, end of period	358,066	252,980
Benefits and CAE payable, end of period	$ 364,385	$ 257,309

DEBT AND WARRANTS - Narrative (

DEBT AND WARRANTS - Narrative (Details) - USD ($)	Mar. 05, 2021	Feb. 21, 2021	Oct. 30, 2020	Mar. 31, 2021	Mar. 31, 2020
Debt Instrument [Line Items]
Debt repayment				$ 153,173,000	$ 0
Debt extinguishment loss				20,178,000	0
Debt prepayment cost				12,994,000	0
Gain (loss) on fair value of warrant liabilities				$ (12,856,000)	$ 860,000
Class A | Common Stock
Debt Instrument [Line Items]
Issuance of common stock upon exercise of warrants and call options (in shares)	1,115,973			1,115,973
Loan payable | Facility Agreement
Debt Instrument [Line Items]
Aggregate principal amount			$ 150,000,000
Interest rate during period				12.75%
Debt repayment	$ 153,200,000
Paid-in-kind interest	3,200,000
Debt extinguishment loss	20,200,000
Debt prepayment cost	13,000,000
Unamortized debt discount and issuance costs written off	$ 7,200,000
Loan payable | LIBOR | Facility Agreement
Debt Instrument [Line Items]
Basis spread on variable rate			11.75%
Line of credit | Revolving credit facility | Revolving Credit Agreement
Debt Instrument [Line Items]
Maximum borrowing capacity		$ 200,000,000
Borrowing capacity, increase limit		$ 50,000,000
Commitment fee		0.50%
Line of credit outstanding				$ 0
Line of credit | Revolving credit facility | LIBOR | Revolving Credit Agreement
Debt Instrument [Line Items]
Basis spread on variable rate		4.50%
Line of credit | Revolving credit facility | Alternative Base Rate | Revolving Credit Agreement
Debt Instrument [Line Items]
Basis spread on variable rate		3.50%
Line of credit | Revolving credit facility | Fed funds effective rate | Revolving Credit Agreement
Debt Instrument [Line Items]
Basis spread on variable rate		0.50%
Line of credit | Revolving credit facility | Adjusted LIBOR | Revolving Credit Agreement
Debt Instrument [Line Items]
Basis spread on variable rate		1.00%

DEBT AND WARRANTS - Schedule of

DEBT AND WARRANTS - Schedule of outstanding warrants (Details) - $ / shares	Mar. 31, 2021	Dec. 31, 2020
Class of Warrant or Right [Line Items]
Warrants outstanding (in shares)		1,225,216
Series AA Warrant
Class of Warrant or Right [Line Items]
Warrants issued (in shares)		629,152
Warrant issue price (in dollars per share)		$ 0.56
Maximum number of preferred stock issuable (in shares)		629,152
Warrants outstanding (in shares)	0	629,152
Series A8 Warrant
Class of Warrant or Right [Line Items]
Warrants issued (in shares)		166,666
Warrant issue price (in dollars per share)		$ 6.75
Maximum number of preferred stock issuable (in shares)		166,666
Warrants outstanding (in shares)	0	166,666
Series A9 Warrant
Class of Warrant or Right [Line Items]
Warrants issued (in shares)		416,666
Warrant issue price (in dollars per share)		$ 7.13
Maximum number of preferred stock issuable (in shares)		416,666
Warrants outstanding (in shares)	0	416,666
Series A11 Call Options
Class of Warrant or Right [Line Items]
Warrants issued (in shares)		4,143,028
Warrant issue price (in dollars per share)		$ 6.02
Maximum number of preferred stock issuable (in shares)		4,143,028
Warrants outstanding (in shares)	0	12,732

CONVERTIBLE PREFERRED STOCK (De

CONVERTIBLE PREFERRED STOCK (Details)	3 Months Ended
	Mar. 31, 2021shares
Increase (Decrease) in Temporary Equity [Roll Forward]
Beginning balance (in shares)	400,904,302
Conversion of stock, shares converted	(400,904,302)
Ending balance (in shares)	0
Series A
Increase (Decrease) in Temporary Equity [Roll Forward]
Beginning balance (in shares)	41,913,800
Conversion of stock, shares converted	(41,913,800)
Ending balance (in shares)	0
Series A1
Increase (Decrease) in Temporary Equity [Roll Forward]
Beginning balance (in shares)	1,371,010
Conversion of stock, shares converted	(1,371,010)
Ending balance (in shares)	0
Series AA
Increase (Decrease) in Temporary Equity [Roll Forward]
Beginning balance (in shares)	22,379,980
Conversion of stock, shares converted	(22,379,980)
Ending balance (in shares)	0
Series AAA
Increase (Decrease) in Temporary Equity [Roll Forward]
Beginning balance (in shares)	36,109,790
Conversion of stock, shares converted	(36,109,790)
Ending balance (in shares)	0
Series A4
Increase (Decrease) in Temporary Equity [Roll Forward]
Beginning balance (in shares)	23,142,080
Conversion of stock, shares converted	(23,142,080)
Ending balance (in shares)	0
Series A5
Increase (Decrease) in Temporary Equity [Roll Forward]
Beginning balance (in shares)	29,189,760
Conversion of stock, shares converted	(29,189,760)
Ending balance (in shares)	0
Series A6
Increase (Decrease) in Temporary Equity [Roll Forward]
Beginning balance (in shares)	29,942,474
Conversion of stock, shares converted	(29,942,474)
Ending balance (in shares)	0
Series A7
Increase (Decrease) in Temporary Equity [Roll Forward]
Beginning balance (in shares)	6,265,845
Conversion of stock, shares converted	(6,265,845)
Ending balance (in shares)	0
Series A8
Increase (Decrease) in Temporary Equity [Roll Forward]
Beginning balance (in shares)	56,434,363
Conversion of stock, shares converted	(56,434,363)
Ending balance (in shares)	0
Series A9
Increase (Decrease) in Temporary Equity [Roll Forward]
Beginning balance (in shares)	23,177,793
Conversion of stock, shares converted	(23,177,793)
Ending balance (in shares)	0
Series AA-9
Increase (Decrease) in Temporary Equity [Roll Forward]
Beginning balance (in shares)	11,820,502
Conversion of stock, shares converted	(11,820,502)
Ending balance (in shares)	0
Series A10
Increase (Decrease) in Temporary Equity [Roll Forward]
Beginning balance (in shares)	53,877,952
Conversion of stock, shares converted	(53,877,952)
Ending balance (in shares)	0
Series A11
Increase (Decrease) in Temporary Equity [Roll Forward]
Beginning balance (in shares)	49,678,169
Conversion of stock, shares converted	(49,678,169)
Ending balance (in shares)	0
Series A12
Increase (Decrease) in Temporary Equity [Roll Forward]
Beginning balance (in shares)	15,600,784
Conversion of stock, shares converted	(15,600,784)
Ending balance (in shares)	0

STOCKHOLDERS' EQUITY (Details)

STOCKHOLDERS' EQUITY (Details) $ / shares in Units, $ in Millions	Mar. 05, 2021USD ($)$ / sharesshares	Mar. 03, 2021$ / sharesshares	Mar. 02, 2021$ / sharesshares	Mar. 31, 2021vote$ / sharesshares	Dec. 31, 2020$ / sharesshares
Subsidiary, Sale of Stock [Line Items]
Conversion of stock, shares converted				400,904,302
Preferred stock, shares authorized		82,500,000		82,500,000
Stock split, conversion ratio		0.33
IPO
Subsidiary, Sale of Stock [Line Items]
Sale of stock, net proceeds | $	$ 1,300
Sale of stock, discounts and commissions | $	$ 71
Preferred Stock converted to Series A
Subsidiary, Sale of Stock [Line Items]
Conversion of stock, shares converted			402,192,500
Class A
Subsidiary, Sale of Stock [Line Items]
Common stock, par value (in dollars per share) | $ / shares		$ 0.00001		$ 0.00001
Common stock, shares authorized		825,000,000		825,000,000
Common stock, conversion ratio				1
Stock split, conversion ratio		3
Common stock, shares outstanding		132,760,639	398,283,107	172,060,630
Voting rights, number of votes | vote				1
Class A | IPO
Subsidiary, Sale of Stock [Line Items]
Number of shares issued in transaction	36,391,946
Stock price (in dollars per share) | $ / shares	$ 39
Class A | Series A reclassified to Class A
Subsidiary, Sale of Stock [Line Items]
Conversion of stock, shares issued			398,283,107
Class A | Class B converted to Class A
Subsidiary, Sale of Stock [Line Items]
Conversion of stock, shares issued		219,772
Series A common stock
Subsidiary, Sale of Stock [Line Items]
Common stock, par value (in dollars per share) | $ / shares			$ 0.00001		$ 0.00001
Common stock, shares authorized					680,000,000
Common stock, shares outstanding					8,291,917
Series A common stock | Preferred Stock converted to Series A
Subsidiary, Sale of Stock [Line Items]
Conversion of stock, shares issued			403,261,643
Series A common stock | Series B converted to Series A
Subsidiary, Sale of Stock [Line Items]
Conversion of stock, shares issued			9,360,800
Series A common stock | Series A reclassified to Class A
Subsidiary, Sale of Stock [Line Items]
Conversion of stock, shares converted			398,283,107
Series A common stock | Series A reclassified to Class B
Subsidiary, Sale of Stock [Line Items]
Conversion of stock, shares converted			45,879,623
Series B common stock
Subsidiary, Sale of Stock [Line Items]
Common stock, par value (in dollars per share) | $ / shares			$ 0.00001		$ 0.00001
Common stock, shares authorized					69,487,963
Common stock, shares outstanding					23,162,654
Series B common stock | Series B converted to Series A
Subsidiary, Sale of Stock [Line Items]
Conversion of stock, shares converted			9,360,800
Series B common stock | Series B reclassified to Class B
Subsidiary, Sale of Stock [Line Items]
Conversion of stock, shares converted			60,127,163
Class B
Subsidiary, Sale of Stock [Line Items]
Common stock, par value (in dollars per share) | $ / shares		$ 0.00001		$ 0.00001
Common stock, shares authorized		82,500,000		82,500,000
Common stock, conversion ratio				1
Stock split, conversion ratio		3
Common stock, shares outstanding		35,335,579	106,006,786	35,115,807
Voting rights, number of votes | vote				20
Class B | Series B reclassified to Class B
Subsidiary, Sale of Stock [Line Items]
Conversion of stock, shares issued			60,127,163
Class B | Series A reclassified to Class B
Subsidiary, Sale of Stock [Line Items]
Conversion of stock, shares issued			45,879,623
Class B | Class B converted to Class A
Subsidiary, Sale of Stock [Line Items]
Conversion of stock, shares converted		219,772

STOCK-BASED COMPENSATION - Narr

STOCK-BASED COMPENSATION - Narrative (Details) - USD ($) $ / shares in Units, $ in Millions	Mar. 05, 2021	Feb. 28, 2021	Mar. 31, 2021	Mar. 31, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense			$ 19.1	$ 8.1
Options granted, weighted average grant date fair value (in dollars per share)			$ 10.42
Unrecognized compensation expense, options			$ 80
Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period			1 year
Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period			4 years
Stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense			$ 13.2	7.5
Maximum contractual term			10 years
Award vesting period			4 years
Unrecognized compensation expense, period for recognition			2 years 10 months 24 days
RSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense			$ 4.3
Unrecognized compensation expense, period for recognition			3 years 2 months 12 days
Unrecognized compensation expense			$ 45.6
Granted (in shares)			908,344
Granted (in dollars per share)			$ 28.38
RSUs | Employee
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted to individual participant (in shares)	17
PSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense			$ 1.6
Award vesting period		7 years
Unrecognized compensation expense, period for recognition			4 years 6 months
Unrecognized compensation expense			$ 88.7
Granted (in shares)		6,344,779	6,344,779
Granted (in dollars per share)			$ 14.22
General and administrative expense
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense			$ 9.4	4
Other insurance cost
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense			$ 9.7	$ 4.1

STOCK-BASED COMPENSATION - Summ

STOCK-BASED COMPENSATION - Summary of stock option award activity (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2021	Dec. 31, 2020
Number of Options
Beginning balance (in shares)	41,115,486
Options granted (in shares)	1,245,593
Options exercised (in shares)	(4,306,297)
Options canceled (in shares)	(400,101)
Ending balance (in shares)	37,654,681	41,115,486
Options exercisable (in shares)	22,887,959
Weighted Average Exercise Price
Beginning balance (in dollars per share)	$ 9.19
Options granted (in dollars per share)	27.03
Options exercised (in dollars per share)	6.92
Options canceled (in dollars per share)	15.86
Ending balance (in dollars per share)	9.95	$ 9.19
Options exercisable (in dollars per share)	$ 8.25
Weighted Average Contractual Life (in years)
Options outstanding, weighted average contractual life	7 years 6 months 21 days	7 years 7 months 2 days
Options exercisable, weighted average contractual life	6 years 6 months 3 days
Aggregate Intrinsic Value
Beginning balance, aggregate intrinsic value	$ 279,477
Options exercised, aggregate intrinsic value	91,855
Ending balance, aggregate intrinsic value	642,569	$ 279,477
Options exercisable, aggregate intrinsic value	$ 426,382

STOCK-BASED COMPENSATION - Su_2

STOCK-BASED COMPENSATION - Summary of valuation assumptions (Details)	3 Months Ended
	Mar. 31, 2021$ / shares
Stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Term in years	5 years 11 months 26 days
Dividend rate	0.00%
Risk free rate of return	0.75%
Volatility	39.40%
PSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Grant date stock price (in dollars per share)	$ 39
Term in years	7 years
Dividend rate	0.00%
Risk free rate of return	1.14%
Volatility	45.00%

STOCK-BASED COMPENSATION - Su_3

STOCK-BASED COMPENSATION - Summary of RSU and PSU activity (Details) - $ / shares	1 Months Ended	3 Months Ended
	Feb. 28, 2021	Mar. 31, 2021	Dec. 31, 2020
RSUs
Number of Shares
Unvested, beginning balance (in shares)		2,463,857	1,555,666
Granted (in shares)		908,344
Canceled (in shares)		(153)
Unvested, ending balance (in shares)		2,463,857
Weighted Average Grant Date Fair Value
Unvested, beginning balance (in dollars per share)		$ 15.82
Granted (in dollars per share)		28.38
Canceled (in dollars per share)		31
Unvested, ending balance (in dollars per share)		$ 20.45
PSUs
Number of Shares
Unvested, beginning balance (in shares)		6,344,779	0
Granted (in shares)	6,344,779	6,344,779
Canceled (in shares)		0
Unvested, ending balance (in shares)		6,344,779
Weighted Average Grant Date Fair Value
Unvested, beginning balance (in dollars per share)		$ 0
Granted (in dollars per share)		14.22
Canceled (in dollars per share)		0
Unvested, ending balance (in dollars per share)		$ 14.22

EARNINGS (LOSS) PER SHARE (Deta

EARNINGS (LOSS) PER SHARE (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Numerator:
Net loss	$ (87,371)	$ (96,879)
Denominator:
Weighted average common shares outstanding, basic	88,865,726	28,874,520
Weighted-average common shares outstanding, diluted	88,865,726	28,874,520
Net loss per share, basic and diluted
Net loss per share, basic (in dollars per share)	$ (0.98)	$ (3.36)
Net loss per share, diluted (in dollars per share)	$ (0.98)	$ (3.36)

VARIABLE INTEREST ENTITIES (Det

VARIABLE INTEREST ENTITIES (Details) - USD ($)	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020
Variable Interest Entity [Line Items]
Assets	$ 3,594,356,000		$ 2,272,106,000
Liabilities	1,808,119,000		1,823,088,000
Revenue	$ 369,388,000	$ 88,103,000
VIE, Integrated Health Systems
Variable Interest Entity [Line Items]
VIE, ownership percentage	50.00%
VIE, Integrated Health Systems | Eliminations
Variable Interest Entity [Line Items]
Expenses through shared savings arrangements	$ 900,000	0
VIE, Professional Corporations
Variable Interest Entity [Line Items]
Assets	1,900,000		1,900,000
Liabilities	9,800,000		$ 7,600,000
Revenue	2,000,000	1,200,000
Operating expenses	$ 4,200,000	$ 2,800,000

SUBSEQUENT EVENTS (Details)

SUBSEQUENT EVENTS (Details)	3 Months Ended
	Mar. 31, 2021
Canada Life
Subsequent Event [Line Items]
Premiums ceded percentage	10.00%

Uncategorized Items - oscr-2021

Label	Element	Value
Restricted Cash and Cash Equivalents	us-gaap_RestrictedCashAndCashEquivalents	$ 16,779,000
Restricted Cash and Cash Equivalents	us-gaap_RestrictedCashAndCashEquivalents	$ 16,473,000