Medicare Advantage in Marshall County, Illinois
1,246 people in Marshall County, Illinois were enrolled in Medicare Advantage in October 2026, 38.1% of 3,273 eligible beneficiaries (−0.1 pts since October 2025). Humana Inc. is the largest parent organization with 41% of reported enrollment; 7 parent organizations have 11 or more members and the HHI is 3,037 (highly concentrated). HRSA classifies the county as fully rural. For 2027, 22 members here are in plans that terminate or leave the county, and Health Care Service Corporation leaves. MA plans offered go from 26 to 22.
Parent organizations in Marshall County
| Parent organization | Members | Change since October 2025 | Share |
|---|---|---|---|
| Humana Inc. | 499 | +106 | 40.7% |
| CVS Health Corporation | 409 | +29 | 33.4% |
| UnitedHealth Group, Inc. | 187 | −44 | 15.3% |
| Centene Corporation | 40 | −22 | 3.3% |
| Elevance Health, Inc. | 36 | 0 | 2.9% |
| Health Care Service Corporation | 33 | +15 | 2.7% |
| Molina Healthcare, Inc. | 21 | −2 | 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, 1,161 beneficiaries in Marshall County were assigned to 18 Medicare Shared Savings Program ACOs, 69.0% of assignable Original Medicare beneficiaries. Together, roughly 81% of all Medicare beneficiaries in the county are in Medicare Advantage or an MSSP ACO. See the ACOs in the MSSP Explorer.