Medicare Advantage in Walworth County, South Dakota
335 people in Walworth County, South Dakota were enrolled in Medicare Advantage in October 2026, 22.0% of 1,526 eligible beneficiaries (−1.2 pts since October 2025). Medica Holding Company is the largest parent organization with 49% of reported enrollment; 4 parent organizations have 11 or more members and the HHI is 3,290 (highly concentrated). HRSA classifies the county as fully rural. For 2027, 268 members here are in plans that terminate or leave the county, and Blue Cross Blue Shield of Michigan Mutual Ins. Co., CVS Health Corporation leave. MA plans offered go from 14 to 5.
Parent organizations in Walworth County
| Parent organization | Members | Change since October 2025 | Share |
|---|---|---|---|
| Medica Holding Company | 162 | +15 | 48.6% |
| Blue Cross Blue Shield of Michigan Mutual Ins. Co. | 75 | +8 | 22.5% |
| CVS Health Corporation | 49 | +2 | 14.7% |
| UnitedHealth Group, Inc. | 47 | −31 | 14.1% |
CMS suppresses county and contract counts of 10 or fewer; shares are of reported enrollment.
Value-based care alongside MA
In PY 2024, 39 beneficiaries in Walworth County were assigned to 11 Medicare Shared Savings Program ACOs, 4.2% of assignable Original Medicare beneficiaries. Together, roughly 25% of all Medicare beneficiaries in the county are in Medicare Advantage or an MSSP ACO. See the ACOs in the MSSP Explorer.