Medicare Advantage in Johnson County, Illinois
1,390 people in Johnson County, Illinois were enrolled in Medicare Advantage in October 2026, 43.2% of 3,215 eligible beneficiaries (+0.8 pts since October 2025). CVS Health Corporation is the largest parent organization with 63% of reported enrollment; 7 parent organizations have 11 or more members and the HHI is 4,380 (highly concentrated). HRSA classifies the county as fully rural. For 2027, 163 members here are in plans that terminate or leave the county, and Health Care Service Corporation leaves. MA plans offered go from 20 to 16.
Parent organizations in Johnson County
| Parent organization | Members | Change since October 2025 | Share |
|---|---|---|---|
| CVS Health Corporation | 875 | +87 | 63.4% |
| Humana Inc. | 210 | +23 | 15.2% |
| UnitedHealth Group, Inc. | 125 | +5 | 9.1% |
| Centene Corporation | 72 | +23 | 5.2% |
| Health Care Service Corporation | 48 | −21 | 3.5% |
| UMWA Health and Retirement Funds | 30 | 0 | 2.2% |
| Molina Healthcare, Inc. | 20 | −4 | 1.4% |
CMS suppresses county and contract counts of 10 or fewer; shares are of reported enrollment.
Value-based care alongside MA
In PY 2024, 427 beneficiaries in Johnson County were assigned to 20 Medicare Shared Savings Program ACOs, 28.5% of assignable Original Medicare beneficiaries. Together, roughly 59% of all Medicare beneficiaries in the county are in Medicare Advantage or an MSSP ACO. See the ACOs in the MSSP Explorer.