Medicare Advantage in Jefferson County, Missouri
34,203 people in Jefferson County, Missouri were enrolled in Medicare Advantage in October 2026, 65.6% of 52,146 eligible beneficiaries (−0.1 pts since October 2025). UnitedHealth Group, Inc. is the largest parent organization with 38% of reported enrollment; 11 parent organizations have 11 or more members and the HHI is 2,395 (highly concentrated). For 2027, 505 members here are in plans that terminate or leave the county. MA plans offered go from 46 to 46.
Parent organizations in Jefferson County
| Parent organization | Members | Change since October 2025 | Share |
|---|---|---|---|
| UnitedHealth Group, Inc. | 12,890 | −645 | 37.7% |
| Lumeris Group Holdings Corporation | 7,575 | +115 | 22.2% |
| CVS Health Corporation | 5,265 | −680 | 15.4% |
| Humana Inc. | 4,971 | +2,069 | 14.6% |
| Elevance Health, Inc. | 1,511 | −374 | 4.4% |
| Blue Cross Blue Shield of Michigan Mutual Ins. Co. | 799 | −23 | 2.3% |
| Devoted Health, Inc. | 454 | +278 | 1.3% |
| Health Care Service Corporation | 370 | +92 | 1.1% |
| Centene Corporation | 225 | +33 | 0.7% |
| Mitchell Family Office | 56 | +1 | 0.2% |
| Rifkin Managed Care Holding, LLC | 33 | −3 | under 0.1% |
CMS suppresses county and contract counts of 10 or fewer; shares are of reported enrollment.
Value-based care alongside MA
In PY 2024, 7,438 beneficiaries in Jefferson County were assigned to 70 Medicare Shared Savings Program ACOs, 59.4% of assignable Original Medicare beneficiaries. Together, roughly 86% of all Medicare beneficiaries in the county are in Medicare Advantage or an MSSP ACO. See the ACOs in the MSSP Explorer.