MA Enrollment Explorer / Parent organizations / Corewell Health
Corewell Health: Medicare Advantage enrollment and market share
Corewell Health had 286,894 Medicare Advantage members in October 2026, #17 nationally with 0.79% of all MA enrollment. It gained 32,274 members (+12.7%) since October 2025, and has enrollment in 4 states and 85 counties with 11 or more members, leading the market in 23 of them. In the 2026 Annual Election Period (December to February) it gained 27,722 members (+10.8%). For 2027, 26,951 of its members are in plans that terminate and 47,484 in plans leaving their county.
287KMA members, October 2026
+12.7%change since October 2025 (+32,274)
0.79%national MA share, rank 17
3contracts with enrollment
Largest states
Largest counties
| County | Members | Change since October 2025 | Share of county MA |
|---|---|---|---|
| Kent County, MI | 56,990 | +2,537 | 61.1% |
| Ottawa County, MI | 32,612 | +1,732 | 66.2% |
| Kalamazoo County, MI | 13,231 | +1,240 | 36.4% |
| Oakland County, MI | 12,640 | +1,284 | 8.1% |
| Muskegon County, MI | 12,586 | +876 | 38.2% |
| Allegan County, MI | 12,050 | +673 | 59.2% |
| Wayne County, MI | 11,461 | +962 | 5.0% |
| Macomb County, MI | 8,731 | +709 | 7.2% |
| Grand Traverse County, MI | 7,743 | +1,225 | 44.3% |
| Newaygo County, MI | 6,120 | +301 | 58.7% |
| Montcalm County, MI | 5,225 | +501 | 45.2% |
| Barry County, MI | 5,216 | +316 | 50.6% |
| Van Buren County, MI | 4,527 | +388 | 35.3% |
| Berrien County, MI | 4,389 | +428 | 19.4% |
| Calhoun County, MI | 3,717 | +671 | 20.4% |
Contracts
| Contract | Plan type | Oct 2024 | Oct 2025 | Oct 2026 |
|---|---|---|---|---|
| H2320 Priority Health Medicare | HMO/HMOPOS | 159,433 | 148,174 | 165,395 |
| H4875 Priority Health Medicare | Local PPO | 82,619 | 98,095 | 113,015 |
| H8379 Priority Health Medicare | HMO/HMOPOS | 9,114 | 8,351 | 8,484 |
Star ratings for these contracts are in the MA Quality Dashboard.