Medicare Advantage in Lake County, Montana
2,519 people in Lake County, Montana were enrolled in Medicare Advantage in October 2026, 28.1% of 8,980 eligible beneficiaries (−2.4 pts since October 2025). Humana Inc. is the largest parent organization with 64% of reported enrollment; 5 parent organizations have 11 or more members and the HHI is 4,962 (highly concentrated). HRSA classifies the county as fully rural. For 2027, 1,055 members here are in plans that terminate or leave the county, and Health Care Service Corporation leaves. MA plans offered go from 13 to 4.
Parent organizations in Lake County
| Parent organization | Members | Change since October 2025 | Share |
|---|---|---|---|
| Humana Inc. | 1,582 | +222 | 63.8% |
| Health Care Service Corporation | 735 | +186 | 29.6% |
| UnitedHealth Group, Inc. | 82 | −568 | 3.3% |
| CVS Health Corporation | 68 | −1 | 2.7% |
| Elevance Health, Inc. | 14 | −1 | 0.6% |
CMS suppresses county and contract counts of 10 or fewer; shares are of reported enrollment.
Value-based care alongside MA
In PY 2024, 3,638 beneficiaries in Lake County were assigned to 38 Medicare Shared Savings Program ACOs, 79.8% of assignable Original Medicare beneficiaries. Together, roughly 85% of all Medicare beneficiaries in the county are in Medicare Advantage or an MSSP ACO. See the ACOs in the MSSP Explorer.