Medicare Advantage in Lake County, California
1,867 people in Lake County, California were enrolled in Medicare Advantage in October 2026, 10.4% of 18,016 eligible beneficiaries (−5.0 pts since October 2025). UnitedHealth Group, Inc. is the largest parent organization with 73% of reported enrollment; 6 parent organizations have 11 or more members and the HHI is 5,482 (highly concentrated). HRSA classifies the county as fully rural. For 2027, 1,175 members here are in plans that terminate or leave the county, and UnitedHealth Group, Inc., Kaiser Foundation Health Plan, Inc., Imperial Health Plan of California leave.
Parent organizations in Lake County
| Parent organization | Members | Change since October 2025 | Share |
|---|---|---|---|
| UnitedHealth Group, Inc. | 1,307 | +223 | 72.6% |
| California Physicians' Service | 180 | −2 | 10.0% |
| Kaiser Foundation Health Plan, Inc. | 171 | −28 | 9.5% |
| Elevance Health, Inc. | 78 | −4 | 4.3% |
| CVS Health Corporation | 35 | −1,080 | 1.9% |
| Imperial Health Plan of California | 30 | new | 1.7% |
CMS suppresses county and contract counts of 10 or fewer; shares are of reported enrollment.
Value-based care alongside MA
In PY 2024, 363 beneficiaries in Lake County were assigned to 50 Medicare Shared Savings Program ACOs, 3.5% of assignable Original Medicare beneficiaries. Together, roughly 13% of all Medicare beneficiaries in the county are in Medicare Advantage or an MSSP ACO. See the ACOs in the MSSP Explorer.