Medicare Advantage in St. Clair County, Michigan
27,029 people in St. Clair County, Michigan were enrolled in Medicare Advantage in October 2026, 62.8% of 43,014 eligible beneficiaries (+0.1 pts since October 2025). Blue Cross Blue Shield of Michigan Mutual Ins. Co. is the largest parent organization with 42% of reported enrollment; 11 parent organizations have 11 or more members and the HHI is 2,687 (highly concentrated). For 2027, 428 members here are in plans that terminate or leave the county. MA plans offered go from 58 to 51.
Parent organizations in St. Clair County
| Parent organization | Members | Change since October 2025 | Share |
|---|---|---|---|
| Blue Cross Blue Shield of Michigan Mutual Ins. Co. | 11,277 | −2,801 | 41.9% |
| Humana Inc. | 6,643 | +1,045 | 24.7% |
| Henry Ford Health System | 3,769 | +2,313 | 14.0% |
| CVS Health Corporation | 2,290 | +93 | 8.5% |
| Corewell Health | 1,971 | +74 | 7.3% |
| Centene Corporation | 410 | +41 | 1.5% |
| UnitedHealth Group, Inc. | 318 | −16 | 1.2% |
| Region VII Area Agency on Aging, Inc. | 131 | +27 | 0.5% |
| McLaren Health Care Corporation | 72 | −32 | 0.3% |
| Longevity Health Founders, LLC | 31 | +12 | 0.1% |
| Molina Healthcare, Inc. | 24 | +2 | under 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, 5,498 beneficiaries in St. Clair County were assigned to 63 Medicare Shared Savings Program ACOs, 44.5% of assignable Original Medicare beneficiaries. Together, roughly 79% of all Medicare beneficiaries in the county are in Medicare Advantage or an MSSP ACO. See the ACOs in the MSSP Explorer.