Medicare Advantage in St. Charles County, Missouri
53,312 people in St. Charles County, Missouri were enrolled in Medicare Advantage in October 2026, 60.5% of 88,070 eligible beneficiaries (+0.1 pts since October 2025). UnitedHealth Group, Inc. is the largest parent organization with 44% of reported enrollment; 11 parent organizations have 11 or more members and the HHI is 2,782 (highly concentrated). HRSA classifies the county as partly rural. For 2027, 1,467 members here are in plans that terminate or leave the county. MA plans offered go from 46 to 46.
Parent organizations in St. Charles County
| Parent organization | Members | Change since October 2025 | Share |
|---|---|---|---|
| UnitedHealth Group, Inc. | 23,306 | −1,244 | 43.8% |
| CVS Health Corporation | 11,395 | −1,590 | 21.4% |
| Humana Inc. | 8,259 | +4,509 | 15.5% |
| Lumeris Group Holdings Corporation | 6,542 | +497 | 12.3% |
| Elevance Health, Inc. | 1,867 | −550 | 3.5% |
| Blue Cross Blue Shield of Michigan Mutual Ins. Co. | 902 | −12 | 1.7% |
| Devoted Health, Inc. | 409 | +278 | 0.8% |
| Health Care Service Corporation | 261 | −6 | 0.5% |
| Centene Corporation | 212 | −1 | 0.4% |
| Rifkin Managed Care Holding, LLC | 49 | 0 | under 0.1% |
| Missouri Healthcare Advisors, LLC | 40 | +6 | 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, 17,264 beneficiaries in St. Charles County were assigned to 120 Medicare Shared Savings Program ACOs, 68.6% of assignable Original Medicare beneficiaries. Together, roughly 88% of all Medicare beneficiaries in the county are in Medicare Advantage or an MSSP ACO. See the ACOs in the MSSP Explorer.