Medicare Advantage in Jefferson County, Colorado
76,795 people in Jefferson County, Colorado were enrolled in Medicare Advantage in October 2026, 62.5% of 122,808 eligible beneficiaries (−0.9 pts since October 2025). UnitedHealth Group, Inc. is the largest parent organization with 48% of reported enrollment; 14 parent organizations have 11 or more members and the HHI is 3,442 (highly concentrated). HRSA classifies the county as partly rural. For 2027, 3,318 members here are in plans that terminate or leave the county. MA plans offered go from 44 to 37.
Parent organizations in Jefferson County
| Parent organization | Members | Change since October 2025 | Share |
|---|---|---|---|
| UnitedHealth Group, Inc. | 36,604 | −2,061 | 47.8% |
| Kaiser Foundation Health Plan, Inc. | 24,528 | +266 | 32.0% |
| Humana Inc. | 8,005 | +2,389 | 10.4% |
| CVS Health Corporation | 3,253 | +65 | 4.2% |
| Devoted Health, Inc. | 2,096 | +782 | 2.7% |
| Total Community Options, Inc. | 562 | +51 | 0.7% |
| Intermountain Health Care, Inc. | 430 | +103 | 0.6% |
| Elevance Health, Inc. | 338 | +79 | 0.4% |
| Denver Health and Hospital Authority | 309 | +38 | 0.4% |
| Health Care Service Corporation | 276 | −828 | 0.4% |
| Blue Cross Blue Shield of Michigan Mutual Ins. Co. | 105 | +5 | 0.1% |
| Longevity Health Founders, LLC | 83 | −11 | 0.1% |
| Highmark Health | 21 | +5 | under 0.1% |
| Perennial Consortium, LLC | 20 | +5 | 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, 14,936 beneficiaries in Jefferson County were assigned to 177 Medicare Shared Savings Program ACOs, 54.8% of assignable Original Medicare beneficiaries. Together, roughly 83% of all Medicare beneficiaries in the county are in Medicare Advantage or an MSSP ACO. See the ACOs in the MSSP Explorer.