Medicare Advantage in Dewey County, South Dakota
94 people in Dewey County, South Dakota were enrolled in Medicare Advantage in October 2026, 10.5% of 892 eligible beneficiaries (−4.4 pts since October 2025). UnitedHealth Group, Inc. is the largest parent organization with 63% of reported enrollment; 2 parent organizations have 11 or more members and the HHI is 5,343 (highly concentrated). HRSA classifies the county as fully rural. For 2027, 24 members here are in plans that terminate or leave the county. MA plans offered go from 11 to 5.
Parent organizations in Dewey County
| Parent organization | Members | Change since October 2025 | Share |
|---|---|---|---|
| UnitedHealth Group, Inc. | 53 | −42 | 63.1% |
| Medica Holding Company | 31 | +8 | 36.9% |
CMS suppresses county and contract counts of 10 or fewer; shares are of reported enrollment.
Value-based care alongside MA
In PY 2024, 109 beneficiaries in Dewey County were assigned to 10 Medicare Shared Savings Program ACOs, 26.0% of assignable Original Medicare beneficiaries. Together, roughly 34% of all Medicare beneficiaries in the county are in Medicare Advantage or an MSSP ACO. See the ACOs in the MSSP Explorer.