Medicare Advantage in Big Horn County, Montana
642 people in Big Horn County, Montana were enrolled in Medicare Advantage in October 2026, 30.3% of 2,122 eligible beneficiaries (+0.3 pts since October 2025). Humana Inc. is the largest parent organization with 71% of reported enrollment; 3 parent organizations have 11 or more members and the HHI is 5,785 (highly concentrated). HRSA classifies the county as fully rural. For 2027, 113 members here are in plans that terminate or leave the county. MA plans offered go from 11 to 5.
Parent organizations in Big Horn County
| Parent organization | Members | Change since October 2025 | Share |
|---|---|---|---|
| Humana Inc. | 448 | +100 | 71.3% |
| UnitedHealth Group, Inc. | 165 | −52 | 26.3% |
| Health Care Service Corporation | 15 | −35 | 2.4% |
CMS suppresses county and contract counts of 10 or fewer; shares are of reported enrollment.
Value-based care alongside MA
In PY 2024, 458 beneficiaries in Big Horn County were assigned to 9 Medicare Shared Savings Program ACOs, 52.6% of assignable Original Medicare beneficiaries. Together, roughly 67% of all Medicare beneficiaries in the county are in Medicare Advantage or an MSSP ACO. See the ACOs in the MSSP Explorer.