Medicare Advantage in Riverside County, California
289,812 people in Riverside County, California were enrolled in Medicare Advantage in October 2026, 63.3% of 457,503 eligible beneficiaries (−0.6 pts since October 2025). Kaiser Foundation Health Plan, Inc. is the largest parent organization with 32% of reported enrollment; 28 parent organizations have 11 or more members and the HHI is 1,781 (moderately concentrated). HRSA classifies the county as partly rural. For 2027, 13,887 members here are in plans that terminate or leave the county, and Local Initiative Health Authority for LA County, Sharp Healthcare, Community Health Group and others leave. MA plans offered go from 56 to 47.
Parent organizations in Riverside County
| Parent organization | Members | Change since October 2025 | Share |
|---|---|---|---|
| Kaiser Foundation Health Plan, Inc. | 91,156 | +4,982 | 31.5% |
| SCAN Group | 62,549 | +8,983 | 21.6% |
| UnitedHealth Group, Inc. | 38,227 | −9,474 | 13.2% |
| Alignment Healthcare USA, LLC | 19,965 | +3,316 | 6.9% |
| INLAND EMPIRE HEALTH PLAN | 18,945 | −197 | 6.6% |
| Humana Inc. | 12,780 | +2,649 | 4.4% |
| Elevance Health, Inc. | 9,886 | −3,226 | 3.4% |
| Astiva Health Holdings Incorporated | 7,334 | +4,198 | 2.5% |
| Molina Healthcare, Inc. | 6,753 | −1,727 | 2.3% |
| Centene Corporation | 5,863 | −3,001 | 2.0% |
| CVS Health Corporation | 4,735 | −3,807 | 1.6% |
| California Physicians' Service | 4,363 | +104 | 1.5% |
| Imperial Health Plan of California | 2,424 | +1,897 | 0.8% |
| Clever Care Health Plan, Inc. | 1,663 | +693 | 0.6% |
| WelbeHealth LLC. | 723 | +337 | 0.3% |
CMS suppresses county and contract counts of 10 or fewer; shares are of reported enrollment.
Value-based care alongside MA
In PY 2024, 23,609 beneficiaries in Riverside County were assigned to 272 Medicare Shared Savings Program ACOs, 23.7% of assignable Original Medicare beneficiaries. Together, roughly 72% of all Medicare beneficiaries in the county are in Medicare Advantage or an MSSP ACO. See the ACOs in the MSSP Explorer.