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Top MA Enrollment Contracts in Seattle-Bellevue-Kent, WA (Jul 2026)
This page summarizes county-level Medicare Advantage enrollment by contract in this metro area.
Home / Data Tools / MA Enrollment / MA MSA Rankings / Seattle-Bellevue-Kent, WA
MSA rank: 38 of top 50 by MA enrollment. CBSA: 42644. MSA total enrollment: 198,158.
Data source: SCC Enrollment MA Alternative File (2026-07).
Top 10 Contracts
| Rank | Contract ID | Organization Name | Plan Type | Enrolled | Counties | MSA Share |
|---|---|---|---|---|---|---|
| 1 | H3805 | UnitedHealthcare Benefits of Texas, Inc. | HMO/HMOPOS | 44,430 | 1 | 22.4% |
| 2 | H5050 | KAISER FOUNDATION HEALTH PLAN OF WASHINGTON | HMO/HMOPOS | 31,265 | 1 | 15.8% |
| 3 | H2001 | SIERRA HEALTH AND LIFE INSURANCE COMPANY, INC. | Local PPO | 28,440 | 1 | 14.4% |
| 4 | H5619 | ARCADIAN HEALTH PLAN, INC. | HMO/HMOPOS | 16,574 | 1 | 8.4% |
| 5 | H5521 | AETNA LIFE INSURANCE COMPANY | Local PPO | 13,583 | 1 | 6.9% |
| 6 | H1036 | HUMANA MEDICAL PLAN, INC. | HMO/HMOPOS | 10,939 | 1 | 5.5% |
| 7 | H5522 | AETNA LIFE INSURANCE COMPANY | Local PPO | 10,387 | 1 | 5.2% |
| 8 | H5008 | CARE IMPROVEMENT PLUS SOUTH CENTRAL INSURANCE CO. | HMO/HMOPOS | 8,797 | 1 | 4.4% |
| 9 | H5216 | HUMANA INSURANCE COMPANY | Local PPO | 7,327 | 1 | 3.7% |
| 10 | H5009 | REGENCE BLUESHIELD | Local PPO | 4,702 | 1 | 2.4% |
Method note: Enrollment is based on legal state/county of residence for payment purposes and may include out-of-service-area beneficiaries.
Related Links
- Previous MSA: Lakewood-New Brunswick, NJ
- Next MSA: Buffalo-Cheektowaga, NY
- All top 50 MSA pages
- MA Enrollment search tool
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