Updated November 2026 for the 2027 plan year. This page lists the health insurance companies selling coverage in California: the insurers on the ACA Marketplace, the companies with the largest share of the commercial market, the Medicaid managed care plans and the leading Medicare Advantage carriers. Kaiser is the largest commercial health insurer in California, with 36% of the market, according to the American Medical Association (AMA).
For coverage you buy yourself, California residents use Covered California. For 2027, 12 insurers are expected to offer Marketplace plans there, based on federal and state filings.
California Health Insurance at a Glance
| Measure | California | Source |
|---|---|---|
| Largest commercial insurer (share of market) | Kaiser (36%) | AMA, 2024 data |
| Second-largest commercial insurer | Elevance Health (Anthem Blue Cross) (24%) | AMA, 2024 data |
| ACA Marketplace | Covered California | |
| Marketplace plan selections, 2026 | 1,927,371 (-2.6% from 2025) | CMS |
| Average monthly Marketplace premium after tax credits | $264 in 2026 ($187 in 2025) | CMS |
| Medicaid enrollees, 2024 | 14,904,950 | CMS |
| Share of Medicaid enrollees in comprehensive managed care | 96.1% | CMS, 2024 |
| Medicare Advantage plans, 2027 | 394 (402 in 2026) | CMS |
| Largest Medicare Advantage carrier | Kaiser (42%) | AMA, 2024 data |
Largest Health Insurance Companies in California
The AMA’s annual Competition in Health Insurance report measures each insurer’s share of enrollment in the commercial market, which includes employer plans and individual coverage, and in Medicare Advantage. The latest edition uses enrollment as of January 1, 2024.
| Market | Largest insurer | Share | Second-largest insurer | Share |
|---|---|---|---|---|
| Commercial (employer and individual) | Kaiser | 36% | Elevance Health (Anthem Blue Cross) | 24% |
| Medicare Advantage | Kaiser | 42% | UnitedHealth Group | 17% |
The Blue Cross Blue Shield licensee in California: Two licensees: Anthem Blue Cross (Elevance Health) and Blue Shield of California. For every company, including national carriers, see our List of Health Insurance Companies.
ACA Marketplace Insurers in California for 2026 and 2027
| Insurer | 2026 | 2027 |
|---|---|---|
| Anthem Blue Cross | Yes | Yes |
| Balance by CCHP | Yes | Yes |
| Blue Shield of California | Yes | Yes |
| CalOptima Health | No | Yes (new, Region 18 / Orange County) |
| Health Net | Yes | Yes |
| Inland Empire Health Plan | Yes | Yes |
| Kaiser Permanente | Yes | Yes |
| L.A. Care Health Plan | Yes | Yes |
| Molina Healthcare | Yes | Yes (exits Regions 15 and 18) |
| Sharp Health Plan | Yes | Yes |
| Valley Health Plan | Yes | Yes |
| Western Health Advantage | Yes | Yes |
Covered California will have 12 insurers in 2027. CalOptima Health enters in Orange County, and Molina leaves two pricing regions. Covered California’s preliminary average rate increase for 2027 is 9.9%.
Source: state exchange and insurance department. Insurer names are brand names; an insurer may sell in only part of the state. Check plans for your ZIP code at Covered California.
Medicaid Managed Care Plans in California
Department of Health Care Services (DHCS) runs Medicaid in California. In 2024, 96.1% of the state’s 14,904,950 Medicaid enrollees were in comprehensive managed care plans, according to CMS; see our Medicaid managed care by state data. Programs: Medi-Cal managed care: County Organized Health System (COHS), Single Plan, Two-Plan, Regional, Geographic Managed Care (GMC) models (2024 county model realignment).
- Alameda Alliance for Health
- Anthem Blue Cross Partnership Plan
- Blue Shield of California Promise Health Plan
- CalOptima Health
- CalViva Health
- CenCal Health
- Central California Alliance for Health
- Community Health Group Partnership Plan
- Contra Costa Health Plan
- Gold Coast Health Plan
- Health Net Community Solutions
- Health Plan of San Joaquin
- Health Plan of San Mateo
- Inland Empire Health Plan
- Kaiser Permanente
- Kern Family Health Care
- L.A. Care Health Plan
- Molina Healthcare of California
- Partnership Health Plan of California
- San Francisco Health Plan
- Santa Clara Family Health Plan
Source: Department of Health Care Services (DHCS).
Medicare Advantage in California
People with Medicare in California can choose from 394 Medicare Advantage plans for 2027, compared with 402 in 2026, and 99.64% have access to a plan with a $0 monthly premium, according to CMS. The largest Medicare Advantage carriers are Kaiser (42%) and UnitedHealth Group (17%), according to the AMA. Compare every state on our Medicare Advantage plans by state page, and see our Medigap vs Medicare Advantage guide before you choose.
Recent Developments in California
- Covered California 2027: preliminary weighted average rate increase of 9.9%; CalOptima Health enters in Orange County (Region 18); Molina exits Regions 15 and 18. (source)
- 2025-26 state budget Medi-Cal changes: an asset test returns (Jan. 1, 2026; $130,000 limit per person). New full-scope enrollment is frozen for adults 19+ without satisfactory immigration status (Jan. 1, 2026). Their routine dental benefits end July 1, 2026. A $30 monthly premium for adults 19–59 in this group starts July 1, 2027. (source)
How To Choose a Health Insurer in California
- Compare Marketplace plans for your ZIP code and update your income to get the right tax credit.
- Check that your doctors and hospitals are in network; our HMO vs PPO vs EPO guide explains the differences.
- Compare the out-of-pocket maximum as well as the premium.
- If your insurer is leaving the Marketplace for 2027, choose a new plan by December 15 for coverage starting January 1.
- For complaints or help with a denied claim, contact the California Department of Managed Health Care and Department of Insurance.
For statewide enrollment and premium trends, see our ACA Marketplace enrollment by state data, and follow our Health Insurance Companies hub for insurer news.
Sources
American Medical Association, Competition in Health Insurance: A Comprehensive Study of U.S. Markets (2025 update, 2024 data); CMS 2026 and 2025 Open Enrollment State-Level Public Use Files; CMS Marketplace plan data files for 2026 and 2027; CMS Medicaid Managed Care Enrollment (2024); CMS 2027 Medicare Advantage and Part D state fact sheets; KFF 2024 Transparency in Coverage data; Department of Health Care Services (DHCS).