Seattle Medicare Plan Non-Renewal: 2027 Steps

Seattle holds about 98,000 of King County's roughly 321,000 residents aged 65 and over, close to 31% of them, according to the Census Bureau's 2020–2024 survey. CMS doesn't count Medicare members by city, but with that many older residents it's a fair assumption that a large share of the King County members affected when a plan pulls out live inside city limits. If one landed in your mailbox, here is what it means for a Seattle resident and what to do before the year runs out.

Seattle and King County by the numbers

CMS doesn't publish Medicare enrollment by city, only by county, so the Medicare rows below are for all of King County. The population rows are Seattle's own.

Measure	Seattle	King County
Population, April 1, 2026 (OFM)	823,400	see county page
Residents 65+ (ACS 2020–2024)	98,196 (13.0%)	320,899 (14.0%)
People with Medicare, July 2026	not published by city	368,813
In Medicare Advantage and other health plans	–	197,594 (53.6%)
In Original Medicare	–	171,219 (46.4%)
On Medicare because of a disability	–	21,859
Dual-eligible (Medicare plus Apple Health)	–	58,692

Sources: WA OFM April 1, 2026 estimates; U.S. Census Bureau ACS 2020–2024, table B09020; CMS Medicare Monthly Enrollment, July 2026 (counts are people, not plans).

Read the middle rows this way: a bit more than half of everyone on Medicare in the county is in Medicare Advantage and other health plans. That is higher than Washington as a whole, where the split is close to even (49.7%). Don't wait for the last two weeks of the year to sort out yours.

What the non-renewal letter actually tells you

A plan that won't renew has to mail each member a notice at least 90 days before coverage stops. For a December 31 end date, that means it should have been mailed by early October. It has to state the end date and describe your other ways to get Medicare coverage. Whether the plan is quitting Medicare entirely or just dropping King County from its service area, CMS treats you the same way and gives you the same special enrollment rights.

The plan keeps paying claims through December 31, 2026. See your doctors, fill prescriptions, keep appointments you already booked. File the notice somewhere safe along with its postmarked envelope. If you apply for Medigap, the insurer is entitled to see evidence that the plan, not you, ended the coverage.

Check your Seattle hospitals and doctors by name

Ten hospitals in the DOH and CMS lists carry a Seattle address, more than any other city in Washington: Harborview Medical Center and University of Washington Medical Center (both UW Medicine), Virginia Mason Medical Center, Fred Hutchinson Cancer Center, Seattle Children's, the Seattle VA Medical Center, the Navos psychiatric hospital in West Seattle, and three more hospitals we don't name here, including two on First Hill and Cherry Hill run by a large regional system.

Lots of choice cuts both ways. A replacement Medicare Advantage plan may include one hospital system and leave out another, and the specialist you see on First Hill may not follow your primary care doctor into the same network. Before you pick anything, write down every doctor, clinic and hospital you used this year and check each one against the 2027 directory of any plan you're considering. If keeping access to all of them matters most to you, remember that Original Medicare works at any provider in the country that accepts Medicare, with no network.

Veterans: the VA Medical Center on Beacon Hill is a VA facility. Using VA care doesn't change your Medicare deadlines, but ask the VA how it fits with whatever you choose.

Your choices and the dates that go with them

Pick a different Medicare Advantage plan offered in King County. Sign up by December 31 and it starts January 1.
Go to Original Medicare and add a stand-alone Part D drug plan, plus a Medigap supplement if you want one.
Do nothing, and Medicare moves you to Original Medicare on January 1, 2027. You keep Parts A and B, but no drug plan is added for you. The exception is people with Extra Help: CMS reassigns them to a stand-alone drug plan unless they already picked one.

Open Enrollment runs to December 7. After that, your plan-ending special enrollment period covers December 8, 2026 through February 28, 2027. Sign up in January and coverage begins February 1; sign up in February and it begins March 1. Those later dates leave weeks without drug coverage, so treat December 31 as the real finish line.

About Medigap: a plan exit triggers a guaranteed issue right under RCW 48.66.055, meaning insurers must sell you certain supplement plans with no health screening, provided you switch to Original Medicare. OIC's timing advice is November 1 or later. The right runs out 63 days after the plan ends: March 4, 2027. Join another Medicare Advantage plan instead and that right goes unused. The statewide guide lists which plan letters you can get.

If you're under 65 and on Medicare

King County has 21,859 people on Medicare because of a disability. If you're one of them, the Medigap road is narrower. Federal law generally doesn't make insurers sell Medigap to people under 65, and OIC says options are more limited for this group. Washington's plan-termination rule has no age limit, but insurers only have to offer what they sell to new customers. Get SHIBA's read on your situation before giving up the plan structure you have.

Where to get help in Seattle

Both of King County's SHIBA sponsor organizations are based in Seattle: Solid Ground on N 45th Street in Wallingford, and the Chinese Information and Service Center on South Lane Street in the Chinatown-International District. Both showed the same notice on OIC's directory when we looked on October 26, 2026: no appointments being accepted, with a referral to Medicare's 1-800 number. So start with the phone:

SHIBA statewide line: 800-562-6900, weekdays 8:30 a.m. to 4:30 p.m. (counseling is free and unbiased)
1-800-MEDICARE (1-800-633-4227), 24 hours a day, 7 days a week except some federal holidays, or Medicare Plan Finder
Seattle - King County Aging & Disability Services, King County's Area Agency on Aging, reachable through Community Living Connections at 206-962-8467

If you need to see Social Security in person, for example to apply for Extra Help, SSA's office list shows a Seattle North office at 13510 Aurora Ave N. Call ahead and confirm the address and hours at ssa.gov/locator before you go.

Getting to new doctors: your Medicare card alone qualifies you for a temporary Regional Reduced Fare Permit, and riders 65 and over qualify by age. With it, a Metro ride costs $1.

What you've read reflects federal Medicare regulations and Washington statute on October 26, 2026. Your plan's letter, not this page, sets your exact dates, and a SHIBA counselor, Medicare's helpline or a licensed agent can confirm them for your case.

Seattle questions we hear

How many people in Seattle are in Medicare Advantage and other health plans?

CMS only reports by county. In King County in July 2026, 197,594 of 368,813 people with Medicare (53.6%) were in Medicare Advantage and other health plans. Seattle itself had 98,196 residents aged 65 and over in the 2020–2024 Census survey.

The plan is only pulling out of King County, not quitting Medicare. Same rules?

Yes. A service area reduction counts the same as a full exit under CMS guidance, so Seattle members get the December 8, 2026 to February 28, 2027 special enrollment period, and Washington’s Medigap guaranteed issue right applies if they choose Original Medicare.

Can I keep seeing doctors at several Seattle hospital systems?

It depends on the network of any new Medicare Advantage plan, so check each provider by name. Original Medicare has no network and works with any provider that accepts Medicare.

Are the Seattle SHIBA offices taking appointments?

On October 26, 2026, OIC listed Solid Ground and CISC as not accepting appointments and pointed people to 1-800-MEDICARE. The statewide SHIBA line, 800-562-6900, was still listed.

Your Medicare Advantage plan isn’t renewing in Seattle. Here’s your plan for the rest of 2026.