Medicare Advantage in Jefferson County, Illinois
2,851 people in Jefferson County, Illinois were enrolled in Medicare Advantage in October 2026, 32.5% of 8,763 eligible beneficiaries (+1.2 pts since October 2025). CVS Health Corporation is the largest parent organization with 47% of reported enrollment; 7 parent organizations have 11 or more members and the HHI is 3,117 (highly concentrated). HRSA classifies the county as fully rural. For 2027, 135 members here are in plans that terminate or leave the county, and Health Care Service Corporation leaves. MA plans offered go from 21 to 13.
Parent organizations in Jefferson County
| Parent organization | Members | Change since October 2025 | Share |
|---|---|---|---|
| CVS Health Corporation | 1,323 | +86 | 47.1% |
| UnitedHealth Group, Inc. | 697 | +48 | 24.8% |
| Humana Inc. | 423 | +81 | 15.0% |
| Centene Corporation | 182 | −26 | 6.5% |
| UMWA Health and Retirement Funds | 107 | −5 | 3.8% |
| Molina Healthcare, Inc. | 54 | −13 | 1.9% |
| Health Care Service Corporation | 25 | −23 | 0.9% |
CMS suppresses county and contract counts of 10 or fewer; shares are of reported enrollment.
Value-based care alongside MA
In PY 2024, 1,588 beneficiaries in Jefferson County were assigned to 38 Medicare Shared Savings Program ACOs, 34.6% of assignable Original Medicare beneficiaries. Together, roughly 56% of all Medicare beneficiaries in the county are in Medicare Advantage or an MSSP ACO. See the ACOs in the MSSP Explorer.