Medicare Advantage in Marathon County, Wisconsin
21,142 people in Marathon County, Wisconsin were enrolled in Medicare Advantage in October 2026, 64.9% of 32,552 eligible beneficiaries (−0.9 pts since October 2025). Sanford Health is the largest parent organization with 56% of reported enrollment; 9 parent organizations have 11 or more members and the HHI is 3,724 (highly concentrated). HRSA classifies the county as partly rural. For 2027, 5,116 members here are in plans that terminate or leave the county, and Aspirus, Inc. leaves. MA plans offered go from 23 to 20.
Parent organizations in Marathon County
| Parent organization | Members | Change since October 2025 | Share |
|---|---|---|---|
| Sanford Health | 11,924 | +376 | 56.5% |
| Humana Inc. | 3,693 | +2,018 | 17.5% |
| UnitedHealth Group, Inc. | 2,550 | −711 | 12.1% |
| Aspirus, Inc. | 1,604 | +977 | 7.6% |
| Elevance Health, Inc. | 804 | −2,462 | 3.8% |
| Centene Corporation | 287 | +52 | 1.4% |
| CVS Health Corporation | 187 | +2 | 0.9% |
| Blue Cross Blue Shield of Michigan Mutual Ins. Co. | 23 | −2 | 0.1% |
| Network Health, Inc. | 20 | +5 | under 0.1% |
CMS suppresses county and contract counts of 10 or fewer; shares are of reported enrollment.
Value-based care alongside MA
In PY 2024, 194 beneficiaries in Marathon County were assigned to 46 Medicare Shared Savings Program ACOs, 2.4% of assignable Original Medicare beneficiaries. Together, roughly 66% of all Medicare beneficiaries in the county are in Medicare Advantage or an MSSP ACO. See the ACOs in the MSSP Explorer.