Medicare Advantage in Washington County, Oregon
68,779 people in Washington County, Oregon were enrolled in Medicare Advantage in October 2026, 64.4% of 106,781 eligible beneficiaries (−1.0 pts since October 2025). UnitedHealth Group, Inc. is the largest parent organization with 31% of reported enrollment; 17 parent organizations have 11 or more members and the HHI is 2,130 (highly concentrated). For 2027, 18,541 members here are in plans that terminate or leave the county, and Providence St Joseph Health, PacificSource, Health Care Service Corporation leave. MA plans offered go from 43 to 32.
Parent organizations in Washington County
| Parent organization | Members | Change since October 2025 | Share |
|---|---|---|---|
| UnitedHealth Group, Inc. | 21,392 | +1,849 | 31.2% |
| Kaiser Foundation Health Plan, Inc. | 16,898 | +701 | 24.6% |
| Providence St Joseph Health | 14,916 | −1,251 | 21.7% |
| Cambia Health Solutions, Inc. | 3,647 | −471 | 5.3% |
| Humana Inc. | 3,407 | +911 | 5.0% |
| CareOregon, Inc. | 2,262 | −420 | 3.3% |
| CVS Health Corporation | 2,027 | +344 | 3.0% |
| Devoted Health, Inc. | 1,278 | +292 | 1.9% |
| Centene Corporation | 1,040 | −191 | 1.5% |
| PacificSource | 642 | −600 | 0.9% |
| Providence Health & Services | 356 | +28 | 0.5% |
| Marquis Companies I, Inc. | 240 | +45 | 0.3% |
| Elevance Health, Inc. | 211 | +5 | 0.3% |
| Health Care Service Corporation | 163 | −279 | 0.2% |
| ATRIO Health Plans | 73 | −10 | 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, 13,894 beneficiaries in Washington County were assigned to 128 Medicare Shared Savings Program ACOs, 66.7% 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.