ORGANIZATION (Policies)	6 Months Ended
Jun. 30, 2026
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation	Basis of Presentation The accompanying interim Condensed Consolidated Financial Statements have been prepared in accordance with accounting principles generally accepted in the United States of America (“U.S. GAAP”) and the applicable rules and regulations of the Securities and Exchange Commission 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 in conformity with U.S. GAAP applicable for the interim periods presented. 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 related notes thereto included in the Company’s Annual Report on Form 10-K filed with the Securities and Exchange Commission for the year ended December 31, 2025. Certain monetary amounts, percentages, and other figures included in this Quarterly Report on Form 10-Q have been subject to rounding adjustments. Percentage amounts included in this Quarterly Report on Form 10-Q have not in all cases been calculated on the basis of such rounded figures, but on the basis of such amounts prior to rounding. For this reason, percentage amounts in this Quarterly Report on Form 10-Q may vary from those obtained by performing the same calculations using the figures in the Company's Condensed Consolidated Financial Statements included elsewhere in this Quarterly Report on Form 10-Q. Certain other amounts that appear in this Quarterly Report on Form 10-Q may not sum due to rounding.
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 Condensed Consolidated Financial Statements and accompanying notes. Significant estimates inherent in the preparation of the accompanying interim Condensed Consolidated Financial Statements include healthcare costs incurred but not yet reported (“IBNR”), and risk adjustment transfers. Estimates are based on past experience, evaluation of current trends, information from third-party professionals, and other considerations that are reasonable under the circumstances. Actual results may differ materially from these estimates.
Reclassification	Reclassification Certain prior period amounts have been reclassified within the components of total current assets and total current liabilities in the Company’s Condensed Consolidated Balance Sheets, as well as within cash flows from operating activities in the Condensed Consolidated Statements of Cash Flows, to conform to the current period presentation. These reclassifications had no impact on the previously reported totals for current assets, current liabilities, or net cash provided by operating activities.
Allowance for Credit Losses	Allowance for Credit Losses The Company’s receivables are reported net of any allowance for credit losses. An allowance for credit losses is generally calculated based on historical collection experience, the counterparty's creditworthiness, and consideration of current and future economic events. As part of value-based care arrangements, the Company entered into risk sharing arrangements with certain of its providers. The intention of these agreements is to align incentives with providers who desire to share accountability for the quality and costs of managing a population of Oscar’s members. If medical expenses exceed agreed upon population-specific target MLR, the provider reimburses the Company an agreed upon portion of the excess expenses creating a risk share receivable due to the Company. The Company recorded risk sharing receivables on a gross basis on the Consolidated Balance Sheet. The Company evaluated expected losses on risk sharing receivables and recorded and adjusted the resulting expected losses to the allowance for credit losses based on the counterparty’s financial health and creditworthiness and any significant changes in the healthcare environment. The Company writes off the receivable balance when it is determined to be uncollectible. A receivable is recorded for commissions that are due to the Company from brokers related to actual or expected retroactive member disenrollments. The Company evaluated expected losses on broker commission chargeback receivables and recorded the resulting expected losses to the allowance for credit losses based on the counterparty’s financial health and creditworthiness, the Company’s historical collection experience, and consideration of current and future economic events over the life of the receivable. The Company writes off the receivable balance when it is determined to be uncollectible.
Accounting Pronouncements - Not Yet Adopted	Accounting Pronouncements - Not Yet Adopted In November 2024, the FASB issued Accounting Standards Update No. 2024-03 (“ASU 2024-03”), Income Statement-Reporting Comprehensive Income-Expense Disaggregation Disclosures (Subtopic 220-40): Disaggregation of Income Statement Expenses, which requires additional disclosures in the Notes to Consolidated Financial Statements, disaggregating specific expense categories for relevant income statement captions and additional disclosures of the Company's total amount of selling expenses. This guidance is effective for annual periods beginning after December 15, 2026, and interim periods beginning after December 15, 2027, with early adoption permitted. While the standard will require additional disclosures related to the Company’s income statement, the standard is not expected to have any material impact on the Company’s consolidated operating results, financial condition, or cash flows. The Company is currently evaluating the impact of the adoption of this guidance on the related disclosures. In September 2025, the FASB issued Accounting Standards Update No. 2025-06 (“ASU 2025-06”), Intangibles–Goodwill and Other – Internal-Use Software (Subtopic 350-40): Targeted Improvements to the Accounting for Internal-Use Software, which modernizes the recognition and disclosure framework for internal-use software costs, removing all references to “development stages” and introducing a more judgment-based approach. This guidance is effective for annual periods beginning after December 15, 2027, and interim periods within those annual reporting periods. This ASU is applicable to the Company’s fiscal year beginning January 1, 2028, with early application permitted. The transition method may be prospective, modified, or retrospective. The Company is currently evaluating the impact of the adoption of this guidance on the Company’s consolidated financial statements and disclosures.
Fair Value Measurements	The Company's financial assets and liabilities measured at fair value on a recurring basis are categorized into a three-level fair value hierarchy based on the priority of the inputs used in the fair value valuation technique. The levels of the fair value hierarchy are as follows: •Level 1: Inputs utilize quoted (unadjusted) prices in active markets for identical assets or liabilities. •Level 2: Inputs utilize quoted prices for similar instruments in active markets; quoted prices for identical or similar instruments in markets that are not active; or model-derived valuations in which all significant inputs are observable in active markets. •Level 3: Inputs utilized are unobservable but significant to the fair value measurement for the asset or liability. The unobservable inputs are used to measure fair value to the extent relevant observable inputs are not available. The unobservable inputs typically reflect management’s own estimates about the assumptions a market participant would use in pricing the asset or liability.

ORGANIZATION (Policies)

6 Months Ended

Jun. 30, 2026

Organization, Consolidation and Presentation of Financial Statements [Abstract]

The accompanying interim Condensed Consolidated Financial Statements have been prepared in accordance with accounting principles generally accepted in the United States of America (“U.S. GAAP”) and the applicable rules and regulations of the Securities and Exchange Commission 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 in conformity with U.S. GAAP applicable for the interim periods presented. 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 related notes thereto included in the Company’s Annual Report on Form 10-K filed with the Securities and Exchange Commission for the year ended December 31, 2025.

Certain monetary amounts, percentages, and other figures included in this Quarterly Report on Form 10-Q have been subject to rounding adjustments. Percentage amounts included in this Quarterly Report on Form 10-Q have not in all cases been calculated on the basis of such rounded figures, but on the basis of such amounts prior to rounding. For this reason, percentage amounts in this Quarterly Report on Form 10-Q may vary from those obtained by performing the same calculations using the figures in the Company's Condensed Consolidated Financial Statements included elsewhere in this Quarterly Report on Form 10-Q. Certain other amounts that appear in this Quarterly Report on Form 10-Q may not sum due to rounding.

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 Condensed Consolidated Financial Statements and accompanying notes. Significant estimates inherent in the preparation of the accompanying interim Condensed Consolidated Financial Statements include healthcare costs incurred but not yet reported (“IBNR”), and risk adjustment transfers. Estimates are based on past experience, evaluation of current trends, information from third-party professionals, and other considerations that are reasonable under the circumstances. Actual results may differ materially from these estimates.

Reclassification

Certain prior period amounts have been reclassified within the components of total current assets and total current liabilities in the Company’s Condensed Consolidated Balance Sheets, as well as within cash flows from operating activities in the Condensed Consolidated Statements of Cash Flows, to conform to the current period presentation. These reclassifications had no impact on the previously reported totals for current assets, current liabilities, or net cash provided by operating activities.

Allowance for Credit Losses

The Company’s receivables are reported net of any allowance for credit losses. An allowance for credit losses is generally calculated based on historical collection experience, the counterparty's creditworthiness, and consideration of current and future economic events.

As part of value-based care arrangements, the Company entered into risk sharing arrangements with certain of its providers. The intention of these agreements is to align incentives with providers who desire to share accountability for the quality and costs of managing a population of Oscar’s members. If medical expenses exceed agreed upon population-specific target MLR, the provider reimburses the Company an agreed upon portion of the excess expenses creating a risk share receivable due to the Company. The Company recorded risk sharing receivables on a gross basis on the Consolidated Balance Sheet. The Company evaluated expected losses on risk sharing receivables and recorded and adjusted the resulting expected losses to the allowance for credit losses based on the counterparty’s financial health and creditworthiness and any significant changes in the healthcare environment. The Company writes off the receivable balance when it is determined to be uncollectible.

A receivable is recorded for commissions that are due to the Company from brokers related to actual or expected retroactive member disenrollments. The Company evaluated expected losses on broker commission chargeback receivables and recorded the resulting expected losses to the allowance for credit losses based on the counterparty’s financial health and creditworthiness, the Company’s historical collection experience, and consideration of current and future economic events over the life of the receivable. The Company writes off the receivable balance when it is determined to be uncollectible.

Accounting Pronouncements - Not Yet Adopted

In November 2024, the FASB issued Accounting Standards Update No. 2024-03 (“ASU 2024-03”), Income Statement-Reporting Comprehensive Income-Expense Disaggregation Disclosures (Subtopic 220-40): Disaggregation of Income Statement Expenses, which requires additional disclosures in the Notes to Consolidated Financial Statements, disaggregating specific expense categories for relevant income statement captions and additional disclosures of the Company's total amount of selling expenses. This guidance is effective for annual periods beginning after December 15, 2026, and interim periods beginning after December 15, 2027, with early adoption permitted. While the standard will require additional disclosures related to the Company’s income statement, the standard is not expected to have any material impact on the Company’s consolidated operating results, financial condition, or cash flows. The Company is currently evaluating the impact of the adoption of this guidance on the related disclosures.

In September 2025, the FASB issued Accounting Standards Update No. 2025-06 (“ASU 2025-06”), Intangibles–Goodwill and Other – Internal-Use Software (Subtopic 350-40): Targeted Improvements to the Accounting for Internal-Use Software, which modernizes the recognition and disclosure framework for internal-use software costs, removing all references to “development stages” and introducing a more judgment-based approach. This guidance is effective for annual periods beginning after December 15, 2027, and interim periods within those annual reporting periods. This ASU is applicable to the Company’s fiscal year beginning January 1, 2028, with early application permitted. The transition method may be prospective, modified, or retrospective. The Company is currently evaluating the impact of the adoption of this guidance on the Company’s consolidated financial statements and disclosures.

Fair Value Measurements

The Company's financial assets and liabilities measured at fair value on a recurring basis are categorized into a three-level fair value hierarchy based on the priority of the inputs used in the fair value valuation technique.

The levels of the fair value hierarchy are as follows:

•Level 1: Inputs utilize quoted (unadjusted) prices in active markets for identical assets or liabilities.

•Level 2: Inputs utilize quoted prices for similar instruments in active markets; quoted prices for identical or similar instruments in markets that are not active; or model-derived valuations in which all significant inputs are observable in active markets.

•Level 3: Inputs utilized are unobservable but significant to the fair value measurement for the asset or liability. The unobservable inputs are used to measure fair value to the extent relevant observable inputs are not available. The unobservable inputs typically reflect management’s own estimates about the assumptions a market participant would use in pricing the asset or liability.