King County is in the cities and suburbs around Puget Sound, from Everett to Olympia, where most Washingtonians live. The county seat is Seattle.
King County is Washington's most populous county and the urban core of the Puget Sound region, with major medical centers.
Communities in King County: Seattle, Bellevue, Kent, Renton, Federal Way, Kirkland, Redmond, Auburn, Sammamish, Shoreline, Burien, Des Moines.
2027 plans in King County at a glance
What it means if you live in King County
- That's 7 plans fewer than in 2026 (37). If you have a Medicare Advantage plan, check your Annual Notice of Change to see whether it continues and what changes. Wellcare stops selling regular Medicare Advantage plans here on December 31; at least 1,316 people in King County are in one of those plans. If that's you, here is what to do. (CMS data) UnitedHealthcare, Humana, Aetna, Regence BlueShield and Kaiser Permanente end some Medicare Advantage plans here while keeping others; at least 21,575 people in King County are in one of those plans. Your plan's letter says whether yours is ending; here is what to do. (CMS data)
- 18 are HMOs (you generally use the plan's network) and 12 are PPOs (which also pay out-of-network doctors, usually at a higher cost to you).
- 8 plans have no Part D drug coverage. Those suit people who get drug coverage elsewhere, such as from the VA; otherwise you could owe a late-enrollment penalty for going without it.
- Special needs plans here: 18 for people with both Medicare and Apple Health (Medicaid); 7 for people with certain chronic conditions, such as diabetes or heart failure; 4 for people who live in a nursing home or need that level of care. You can join one only if you qualify.
- King County ranks 5th of Washington's 39 counties for plans open to everyone. In the Puget Sound region (5 counties), the count runs from 28 to 35.
- At least 196,954 people in King County were in a Medicare Advantage plan in October 2026.
Licensed insurance agents for King County
These independent insurance agents are licensed in Washington and work with Benefits Life, the publisher of this site. When they enroll you in a plan, the agent and Benefits Life may be paid by the insurance company. Learn more.
See Medicare plans in King County
Enter your ZIP code to compare Medicare Advantage, Part D, and Medigap plans available where you live.
You'll go to PlanMatchMedicare.com, a plan comparison site from Benefits Life, the publisher of this site. Only your ZIP code is sent.
Original Medicare and Medigap
If you'd rather keep any doctor who takes Medicare, Original Medicare with a Medigap policy and a Part D plan works the same in every Washington county. Medigap in Washington.
Nearby counties
You can only join a Medicare Advantage plan sold in the county where you live.
| County | Plans open to everyone, 2027 | Special needs plans |
|---|---|---|
| Pierce County | 35 | 31 |
| Snohomish County | 31 | 29 |
| Kitsap County | 28 | 28 |
| Kittitas County | 5 | 15 |
2026 Medicare costs (the same in every county)
| Cost | 2026 |
|---|---|
| Part B premium | $202.90 a month (standard) |
| Part B deductible | $283 a year |
| Part A deductible | $1,736 per benefit period |
| Part D out-of-pocket cap | $2,100 a year |
Other places to get answers
- Medicare: 1-800-MEDICARE (1-800-633-4227), TTY 1-877-486-2048, 24 hours a day, or Medicare.gov.
- Social Security (signing up for Parts A and B, Extra Help): 1-800-772-1213, TTY 1-800-325-0778.
- Apple Health (Washington Medicaid, and help with Medicare costs): hca.wa.gov.
- Washington State Office of the Insurance Commissioner (complaints about an insurance company or agent): insurance.wa.gov.
Questions about Medicare in King County
How many Medicare Advantage plans are there in King County for 2027?
CMS lists 30 open to everyone with Medicare (37 in 2026), plus 29 special needs plans for people who qualify. You still pay your Part B premium.
When can I change my Medicare plan in King County?
Open Enrollment runs October 15 to December 7, for coverage starting January 1. If you're in a Medicare Advantage plan, you can switch plans or go back to Original Medicare once between January 1 and March 31. If your plan leaves your county, you get a Special Enrollment Period.
How do I find a licensed insurance agent in King County?
Use the agent search on this page, or call (206) SENIORS (206-736-4677), TTY 711 to compare plans with a licensed insurance agent at no cost to you. Agents listed here are licensed in Washington.
Sources
Plans open to everyone are Medicare Advantage plans with or without drug coverage, not special needs plans. Enrollment counts HMO and PPO plans; CMS hides counts of 10 or fewer, so real numbers are a little higher.