Medicare Advantage in Stephenson County, Illinois
7,542 people in Stephenson County, Illinois were enrolled in Medicare Advantage in October 2026, 62.0% of 12,164 eligible beneficiaries (+0.02 pts since October 2025). CVS Health Corporation is the largest parent organization with 60% of reported enrollment; 7 parent organizations have 11 or more members and the HHI is 4,106 (highly concentrated). HRSA classifies the county as fully rural. For 2027, 66 members here are in plans that terminate or leave the county, and Health Care Service Corporation leaves. MA plans offered go from 33 to 24.
Parent organizations in Stephenson County
| Parent organization | Members | Change since October 2025 | Share |
|---|---|---|---|
| CVS Health Corporation | 4,517 | −32 | 60.1% |
| Humana Inc. | 1,396 | +402 | 18.6% |
| UnitedHealth Group, Inc. | 726 | −184 | 9.7% |
| Highmark Health | 499 | −19 | 6.6% |
| Centene Corporation | 222 | −51 | 3.0% |
| Molina Healthcare, Inc. | 96 | +7 | 1.3% |
| Health Care Service Corporation | 59 | +19 | 0.8% |
CMS suppresses county and contract counts of 10 or fewer; shares are of reported enrollment.
Value-based care alongside MA
In PY 2024, 1,075 beneficiaries in Stephenson County were assigned to 37 Medicare Shared Savings Program ACOs, 31.6% of assignable Original Medicare beneficiaries. Together, roughly 74% of all Medicare beneficiaries in the county are in Medicare Advantage or an MSSP ACO. See the ACOs in the MSSP Explorer.