MA Enrollment Explorer / Parent organizations / Contra Costa Health Services
Contra Costa Health Services: Medicare Advantage enrollment and market share
Contra Costa Health Services had 648 Medicare Advantage members in October 2026, #188 nationally with 0.00% of all MA enrollment. It gained 648 members (new) since October 2025, and has enrollment in 1 state and 1 counties with 11 or more members. It entered MA in the 2026 Annual Election Period with 238 members by February. For 2027, none of its members are in plans that terminate or leave their county.
648MA members, October 2026
newchange since October 2025 (+648)
0.00%national MA share, rank 188
1contracts with enrollment
Largest states
| State | Members | Share of state MA |
|---|---|---|
| California | 623 | 0.0% |
Largest counties
| County | Members | Change since October 2025 | Share of county MA |
|---|---|---|---|
| Contra Costa County, CA | 623 | new | 0.5% |
Contracts
| Contract | Plan type | Oct 2024 | Oct 2025 | Oct 2026 |
|---|---|---|---|---|
| H5119 Contra Costa Health Care Plus (HMO D-SNP) | HMO/HMOPOS | n/a | n/a | 648 |
Star ratings for these contracts are in the MA Quality Dashboard.