Medicare Advantage in Orange County, California
341,720 people in Orange County, California were enrolled in Medicare Advantage in October 2026, 55.9% of 610,935 eligible beneficiaries (−0.1 pts since October 2025). Kaiser Foundation Health Plan, Inc. is the largest parent organization with 26% of reported enrollment; 28 parent organizations have 11 or more members and the HHI is 1,577 (moderately concentrated). HRSA classifies the county as partly rural. For 2027, 18,683 members here are in plans that terminate or leave the county, and Providence St Joseph Health, Molina Healthcare, Inc., Local Initiative Health Authority for LA County and others leave. MA plans offered go from 64 to 62.
Parent organizations in Orange County
| Parent organization | Members | Change since October 2025 | Share |
|---|---|---|---|
| Kaiser Foundation Health Plan, Inc. | 87,695 | +3,424 | 25.7% |
| SCAN Group | 86,642 | +24,377 | 25.4% |
| UnitedHealth Group, Inc. | 36,264 | −16,029 | 10.6% |
| Orange County Health Authority | 19,405 | +1,053 | 5.7% |
| CVS Health Corporation | 17,285 | +2,216 | 5.1% |
| California Physicians' Service | 16,545 | −5,488 | 4.8% |
| Elevance Health, Inc. | 14,868 | −4,498 | 4.4% |
| Astiva Health Holdings Incorporated | 14,671 | +1,199 | 4.3% |
| Humana Inc. | 13,050 | +996 | 3.8% |
| Clever Care Health Plan, Inc. | 12,721 | +6,480 | 3.7% |
| Alignment Healthcare USA, LLC | 9,172 | +2,569 | 2.7% |
| Centene Corporation | 5,238 | −1,652 | 1.5% |
| Providence St Joseph Health | 3,927 | −4,666 | 1.2% |
| Molina Healthcare, Inc. | 1,956 | −1,383 | 0.6% |
| Imperial Health Plan of California | 385 | +109 | 0.1% |
CMS suppresses county and contract counts of 10 or fewer; shares are of reported enrollment.
Value-based care alongside MA
In PY 2024, 46,484 beneficiaries in Orange County were assigned to 281 Medicare Shared Savings Program ACOs, 25.9% of assignable Original Medicare beneficiaries. Together, roughly 67% of all Medicare beneficiaries in the county are in Medicare Advantage or an MSSP ACO. See the ACOs in the MSSP Explorer.