Medicare Advantage in Carter County, Oklahoma
4,216 people in Carter County, Oklahoma were enrolled in Medicare Advantage in October 2026, 36.2% of 11,631 eligible beneficiaries (+1.1 pts since October 2025). UnitedHealth Group, Inc. is the largest parent organization with 46% of reported enrollment; 6 parent organizations have 11 or more members and the HHI is 3,328 (highly concentrated). HRSA classifies the county as fully rural. For 2027, 526 members here are in plans that terminate or leave the county, and Health Care Service Corporation leaves. MA plans offered go from 22 to 12.
Parent organizations in Carter County
| Parent organization | Members | Change since October 2025 | Share |
|---|---|---|---|
| UnitedHealth Group, Inc. | 1,902 | −175 | 45.6% |
| Humana Inc. | 1,359 | +101 | 32.6% |
| CVS Health Corporation | 523 | +129 | 12.5% |
| MHH Healthcare, L.P. | 212 | +104 | 5.1% |
| Health Care Service Corporation | 124 | +39 | 3.0% |
| Mitchell Family Office | 55 | +7 | 1.3% |
CMS suppresses county and contract counts of 10 or fewer; shares are of reported enrollment.
Value-based care alongside MA
In PY 2024, 2,472 beneficiaries in Carter County were assigned to 35 Medicare Shared Savings Program ACOs, 45.6% of assignable Original Medicare beneficiaries. Together, roughly 65% of all Medicare beneficiaries in the county are in Medicare Advantage or an MSSP ACO. See the ACOs in the MSSP Explorer.