Medicare Advantage in Snohomish County, Washington
91,835 people in Snohomish County, Washington were enrolled in Medicare Advantage in October 2026, 59.6% of 154,191 eligible beneficiaries (−0.6 pts since October 2025). UnitedHealth Group, Inc. is the largest parent organization with 53% of reported enrollment; 14 parent organizations have 11 or more members and the HHI is 3,519 (highly concentrated). HRSA classifies the county as partly rural. For 2027, 15,144 members here are in plans that terminate or leave the county, and Providence St Joseph Health leaves. MA plans offered go from 42 to 31.
Parent organizations in Snohomish County
| Parent organization | Members | Change since October 2025 | Share |
|---|---|---|---|
| UnitedHealth Group, Inc. | 48,930 | +4,932 | 53.4% |
| Humana Inc. | 20,020 | −2,245 | 21.8% |
| Kaiser Foundation Health Plan, Inc. | 9,531 | −309 | 10.4% |
| CVS Health Corporation | 8,068 | −207 | 8.8% |
| Cambia Health Solutions, Inc. | 2,180 | −323 | 2.4% |
| Molina Healthcare, Inc. | 877 | +16 | 1.0% |
| Centene Corporation | 675 | −78 | 0.7% |
| Providence St Joseph Health | 453 | −55 | 0.5% |
| Community Health Plan of Washington | 425 | −122 | 0.5% |
| Providence Health & Services | 231 | +45 | 0.3% |
| Elevance Health, Inc. | 199 | −9 | 0.2% |
| Blue Cross Blue Shield of Michigan Mutual Ins. Co. | 45 | −2 | under 0.1% |
| California Physicians' Service | 20 | +1 | under 0.1% |
| Health Care Service Corporation | 18 | +7 | 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, 23,562 beneficiaries in Snohomish County were assigned to 143 Medicare Shared Savings Program ACOs, 66.4% 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.