Quick answer
CMS lists 30 Medicare Advantage plans from 6 insurers that people with Medicare can join in King County, Washington for 2027. 18 have a $0 monthly premium and 22 include drug coverage. In-network out-of-pocket maximums run from $3,150 to $9,850 a year. 19 of the 26 plans with a 2027 star rating have 4 or more stars. Data last updated September 22, 2026 (CMS landscape 202609.1); star ratings October 8, 2026.
We do not offer every plan available in your area. Currently we represent a small number of insurance agencies and the plans they carry. Please contact Medicare.gov, 1-800-MEDICARE (TTY 1-877-486-2048), 24 hours a day / 7 days a week, or your local State Health Insurance Assistance Program (SHIP) to get information on all of your options.
We are an independent information and referral resource. We are not connected with, endorsed by, or acting on behalf of the United States government, the Centers for Medicare & Medicaid Services, or the federal Medicare program. Calling a number on this page connects you with a licensed insurance agent or a third-party marketing partner.
2027 plan numbers for King County
King County at a glance
- Plans open to everyone
- 30
- With a $0 monthly premium
- 18
- With drug coverage
- 22
- In-network out-of-pocket maximum
- $3,150 to $9,850
- Insurers with plans
- 6
- Plans rated 4+ stars
- 19 of 26 rated
- Special needs plans (qualifying members only)
- 29
Plans open to everyone means Medicare Advantage and Medicare Advantage with drug coverage plans that are not special needs plans. Premium means the plan premium; your Part B premium is separate.
King County ranks #13 among US counties by population (Census estimate for July 1, 2025: 2,344,939 people). By number of plans offered it ranks #5 of the 39 counties in Washington that have plans, and #1053 of the 3,040 counties in the country that have plans.
Plans by type
| Plan type | Plans | What it generally means |
|---|---|---|
| HMO | 13 | Care usually has to come from the plan's network. |
| HMO with point-of-service (HMO-POS) | 5 | An HMO that covers some out-of-network care. |
| PPO | 12 | Out-of-network care is allowed, usually at a higher cost. |
Insurers with plans in King County
| Insurer | Plans in King County | Share of plans |
|---|---|---|
| Humana | 9 | 30% |
| UnitedHealthcare | 7 | 23% |
| Aetna Medicare | 5 | 17% |
| Kaiser Permanente | 4 | 13% |
| Devoted Health | 3 | 10% |
| Regence BlueShield | 2 | 7% |
How King County compares with the rest of Washington
The state column is the average of the 39 Washington counties that have Medicare Advantage plans in the CMS file; each county counts once, whatever its population.
| Measure | King County | Average Washington county |
|---|---|---|
| Plans open to everyone | 30 | 12.1 |
| Plans with a $0 premium | 60% | 52% |
| Insurers with plans | 6 | 2.6 |
| PPO and Regional PPO share of plans | 40% | 65% |
| Lowest out-of-pocket maximum | $3,150 | $4,287 |
| Highest out-of-pocket maximum | $9,850 | $9,213 |
| Rated plans with 4+ stars | 73% | 90% |
| Plans with drug coverage | 73% | 64% |
- With 30 plans on offer, King County has roughly 2.5 times as many as the average Washington county (12.1).
- 6 insurers sell plans in King County, above the Washington county average of 2.6.
- 40% of the plans in King County are PPOs or Regional PPOs, against 65% for the average Washington county.
- 19 of the 26 plans with a star rating (73%) are rated 4 stars or higher, versus 90% in the average Washington county.
What this means in King County
30 plans from 6 insurers puts King County well above the Washington county norm (state county average: 12.1). Cut the list by doctors and prescriptions first, since a plan that leaves out either is not a fit at any premium. More insurers means more provider networks to check against your doctors. Fewer PPO-type plans than usual means network fit matters more here. 18 of 30 plans have a $0 premium and the rest charge one, so weigh premium against the out-of-pocket maximum, which is $3,150 to $9,850. A $0 premium does not remove copays or coinsurance, and your Part B premium is separate.
The list mixes 18 HMO-style and 12 PPO-style plans, so network rules differ from plan to plan; read each plan's provider rules. 19 of the 26 rated plans have 4 or more stars. CMS rates the insurer's contract, so look up the rating of the specific plan you are considering.
How to compare plans in King County
- Doctors and hospitals. Ask each plan whether your doctors, your hospital and any specialists are in its network today. 18 of 30 plans here are HMO or HMO-POS and 12 are PPO-type, so the rules differ.
- Prescriptions. 22 of 30 plans include drug coverage. For each drug, check the plan's formulary, the tier it sits on and the pharmacy you would use.
- Out-of-pocket cap. The in-network maximum runs $3,150 to $9,850 a year depending on the plan, a gap of $6,700. The cap is what limits a hospital stay or a run of treatments.
- Extras and cost-sharing. Compare copays for primary care, specialists and the emergency room, and any dental, vision and hearing benefits you would use.
- Star rating. 19 of the 26 rated plans have 4 or more stars. Ask for the rating of the exact plan, then see how it handles the doctors and drugs above.
Plan Finder at Medicare.gov shows every plan available at your address. If your ZIP code is in King County, you can also check plan counts for your ZIP code on this site.
Dates that matter for 2027 coverage
- Open enrollment runs October 15 to December 7, 2026. You can join, switch or drop a Medicare Advantage plan in that window.
- Coverage changes take effect January 1, 2027. Plans send an Annual Notice of Change in the fall listing what is different next year.
Free local Medicare help in Washington
The State Health Insurance Assistance Program (SHIP) gives free, unbiased Medicare counseling. In Washington it is run as Statewide Health Insurance Benefits Advisors (SHIBA).
SHIBA in Washington
- Program
- Statewide Health Insurance Benefits Advisors (SHIBA)
- Phone
- 1-800-562-6900 (TTY 1-360-586-0241)
- Website
- insurance.wa.gov/insurance-resources/medicare
Program name, number and website as listed by the SHIP National Technical Assistance Center, checked October 15, 2026.
You can also reach Medicare at 1-800-MEDICARE (1-800-633-4227, TTY 1-877-486-2048) or compare plans at medicare.gov/plan-compare.
Questions about Medicare Advantage in King County
How many Medicare Advantage plans are in King County for 2027?
CMS lists 30 general Medicare Advantage plans in King County, Washington for 2027: 13 HMO, 5 HMO-POS, and 12 PPO. 22 of them include drug coverage. That count leaves out special needs plans (29 more, for people who qualify), cost plans and stand-alone drug plans.
Are there $0 premium Medicare Advantage plans in King County?
Yes. 18 of the 30 plans (60%) have a $0 monthly plan premium. You still pay your Part B premium, and the plan may charge copays or coinsurance up to its out-of-pocket maximum.
Which insurers offer Medicare Advantage plans in King County?
6 insurers offer plans in King County, Washington. The five with the most plans are Humana (9), UnitedHealthcare (7), Aetna Medicare (5), Kaiser Permanente (4), Devoted Health (3).
What is the most I could pay out of pocket in King County?
In-network out-of-pocket maximums for the 30 plans run from $3,150 to $9,850 a year, depending on the plan. The maximum covers covered services in the plan's network; it does not include the plan's monthly premium.
How many Medicare Advantage plans in King County have 4 or more stars?
19 of the 26 plans with a 2027 star rating are rated 4 stars or higher. 4 plans are not yet rated or have too little data, and star ratings are given to the insurer's contract.
Sources and what is counted
Source: CMS Medicare Advantage and Part D Landscape source file, contract year 2027, release 202609.1 (file cy2027-landscape-202609-1.zip, CY2027_Landscape_202609.csv), data last updated September 22, 2026; CMS 2027 Part C and D Star Ratings data tables (Summary Ratings table), October 8, 2026; U.S. Census Bureau Vintage 2025 county population estimates (July 1, 2025). Plans counted by Senior Transition Assistance.
A plan is one CMS contract and plan ID offered in King County. Counts cover Medicare Advantage and Medicare Advantage with drug coverage plans that are open to everyone. Special needs plans, cost plans, employer-only plans and stand-alone Part D plans are not in the counts above. The $0-premium count uses the combined plan premium (Part C plus Part D) when the plan has drug coverage. Star ratings are CMS overall ratings for plans with drug coverage and Part C summary ratings for plans without. Out-of-pocket maximums are the in-network amounts CMS lists.
Figures are for plan year 2027 and come from CMS files dated as shown; the CMS landscape can change before January 1. Confirm any plan's details on Medicare.gov or with the plan.