Medicare Advantage in Sanborn County, South Dakota
204 people in Sanborn County, South Dakota were enrolled in Medicare Advantage in October 2026, 33.5% of 609 eligible beneficiaries (−1.5 pts since October 2025). Blue Cross Blue Shield of Michigan Mutual Ins. Co. is the largest parent organization with 45% of reported enrollment; 4 parent organizations have 11 or more members and the HHI is 3,351 (highly concentrated). HRSA classifies the county as fully rural. For 2027, 100 members here are in plans that terminate or leave the county, and Blue Cross Blue Shield of Michigan Mutual Ins. Co. leaves. MA plans offered go from 12 to 7.
Parent organizations in Sanborn County
| Parent organization | Members | Change since October 2025 | Share |
|---|---|---|---|
| Blue Cross Blue Shield of Michigan Mutual Ins. Co. | 89 | −22 | 44.7% |
| Medica Holding Company | 65 | +38 | 32.7% |
| UnitedHealth Group, Inc. | 30 | +6 | 15.1% |
| CVS Health Corporation | 15 | −19 | 7.5% |
CMS suppresses county and contract counts of 10 or fewer; shares are of reported enrollment.
Value-based care alongside MA
In PY 2024, 208 beneficiaries in Sanborn County were assigned to 6 Medicare Shared Savings Program ACOs, 66.8% of assignable Original Medicare beneficiaries. Together, roughly 78% of all Medicare beneficiaries in the county are in Medicare Advantage or an MSSP ACO. See the ACOs in the MSSP Explorer.