UnitedHealthcare, the insurance arm of UnitedHealth Group, is the largest health insurer in the United States. It covered 48.3 million medical members at the end of September 2026 according to the company, and its parent reported $447.6 billion in revenue for 2025, more than any other health care company.
UnitedHealth Group also owns Optum, which runs one of the three largest pharmacy benefit managers (Optum Rx), a large network of physician practices and a health data business. That combination of insurer, pharmacy manager and care provider makes it the most vertically integrated company in American health care, and the most scrutinized.
Updated November 2026. This profile draws on company filings, federal data and Health Plan News analysis. It is independent of UnitedHealthcare; for questions about your coverage, call the number on your member ID card.
UnitedHealthcare at a Glance
| Item | Details |
|---|---|
| Parent company | UnitedHealth Group Incorporated (NYSE: UNH) |
| Headquarters | Eden Prairie, Minnesota |
| CEO | Stephen J. Hemsley (returned May 13, 2025, after Andrew Witty stepped down) |
| Insurance brands | UnitedHealthcare, UnitedHealthcare Community Plan (Medicaid), AARP Medicare plans from UnitedHealthcare, Golden Rule, Oxford |
| 2025 revenue | $447.6 billion |
| Medical members | 48.3 million (September 30, 2026) |
| Medicare Advantage | 7.6 million members; 26% of national Medicare Advantage enrollment in 2026 (KFF) |
| ACA Marketplace | 29 states in 2027; leaving Georgia |
| Medicaid | 32 states and the District of Columbia |
| Pharmacy benefit manager | Optum Rx |
Medicare Advantage
UnitedHealthcare is the largest Medicare Advantage insurer, with 26% of national enrollment in 2026, down from 29%, according to KFF. It leads Medicare Advantage in 30 states, from Alabama to Wisconsin, in the AMA’s state data. Many of those plans carry the AARP name under a licensing agreement.
The company is pulling back. Its Medicare Advantage membership fell from 8.45 million at the end of 2025 to 7.6 million by September 2026, and it is discontinuing plans covering about 390,000 people for 2027, a spokesperson told Bloomberg (source). Its average star rating for 2027 fell to 3.57 from 3.82.
ACA Marketplace and Employer Coverage
UnitedHealthcare will sell individual Marketplace plans in 29 states in 2027 and is adding service areas in Arizona, Florida, Indiana, Kansas and Michigan. It is leaving Georgia Access on January 1, 2027, after state regulators pushed back on a requested rate increase of about 54% (source).
Employer coverage remains its largest business by membership: 22.2 million people in self-funded plans the company administers and 7.6 million in fully insured group plans.
Medicaid
UnitedHealthcare Community Plan runs Medicaid programs in 32 states and the District of Columbia. Its Medicaid enrollment fell from 7.38 million to 6.70 million during 2026, partly because Louisiana did not extend its contract amid state litigation over pharmacy pricing (source).
UnitedHealthcare by the Numbers: Health Plan News Data
- Commercial (employer and individual) market: largest insurer in 5 states (Arizona, Colorado, Nevada, New York, Wisconsin) and second-largest in 17, based on 2024 AMA data.
- Aca exchange market: largest insurer in 1 state (Nevada) and second-largest in 2, based on 2024 AMA data.
- Medicare advantage market: largest insurer in 30 states (Alabama, Arizona, Arkansas, Colorado, Connecticut, Delaware, District of Columbia, Georgia and others) and second-largest in 11, based on 2024 AMA data.
- Claim denials: its HealthCare.gov plans denied 19.2% of in-network claims in 2024 across 15 states, compared with 18.7% for all HealthCare.gov insurers (federal Transparency in Coverage data compiled by KFF).
Compare insurers in every state on our health insurance market share by state page and our claim denial rates by insurer report.
Recent UnitedHealthcare News
- Leadership: Andrew Witty stepped down as CEO in May 2025, and former CEO Stephen Hemsley returned; the company suspended its 2025 guidance at the time. (source)
- Federal investigations: UnitedHealth confirmed in July 2025 that it is cooperating with Department of Justice criminal and civil investigations into its Medicare Advantage business. (source)
- AI denial lawsuit: A class action, Estate of Lokken v. UnitedHealth Group, alleges the naviHealth nH Predict tool was used to deny post-acute care to Medicare Advantage members; the company disputes the claims. (source)
- 2026 results: Third-quarter 2026 revenue was $112.7 billion and the medical care ratio improved to 88.4%; the company raised its 2026 adjusted earnings guidance to at least $20.50 a share. (source)
How To Contact UnitedHealthcare
| Purpose | Contact |
|---|---|
| Employer plan members | 1-866-801-4409 (TTY 711) |
| Medicare Supplement (AARP) | 1-800-523-5800 (TTY 711) |
| Medicare Advantage, Medicaid and Marketplace members | Number on your member ID card |
| Website | uhc.com |
For profiles of other carriers, see our List of Health Insurance Companies and follow our Health Insurance Companies hub.
Sources
ArentFox Schiff via JD Supra; Becker’s Hospital Review; Becker’s Payer Issues; Becker’s Payer Issues, 8 things to know about 2027 Medicare Advantage star ratings; healthcaredive.com, 2027 MA star ratings winners and losers; Becker’s Payer Issues, How insurers’ ACA footprints are changing in 2027; Becker’s Payer Issues, Medicare Advantage insurers ranked by county entries, exits in 2027; Fierce Healthcare; InsuranceNewsNet (Louisiana Illuminator), La. cuts two Medicaid contracts; KFF, Medicare Advantage in 2026: Enrollment Update and Key Trends; KFF, Tracking Insurer Participation Changes in the ACA Marketplaces in 2027; American Medical Association, Competition in Health Insurance (2025 update); KFF, Medicare Advantage in 2026; CMS Transparency in Coverage public use file (2024, via KFF).