Medicare Advantage

On January 1, Original Medicare kicks in if you do nothing

King County has 59 Medicare Advantage plans for 2027. Compared with 2026, 27 plans are not coming back, 18 are new, and 31 continuing plans changed in some way you should check before December 7, 10 of them under a new name. This guide covers what those numbers mean for Seattle, not which plan to pick.

Seattle — Fall 2026. If you have a Medicare Advantage plan in the Seattle area, your mailbox matters this month. The Centers for Medicare & Medicaid Services (CMS) has published the 2027 plan lineup, and 27 Medicare Advantage plans sold in King County this year are not being offered again for 2027. People enrolled in those plans are getting a non-renewal letter from their insurer, and the choices they make — or don't make — before year's end will decide how they're covered on January 1.

Seattle is in King County, where Medicare Advantage availability is set. For 2027, 59 Medicare Advantage plans from 11 carriers will be offered in the county, down from 68 plans from 10 carriers in 2026.

How to tell if your plan is one of them

If your current Medicare Advantage plan is not being offered in 2027, your insurer is required to mail you a non-renewal letter — usually arriving in October. It will say the plan will not be available next year and that your Medicare Advantage coverage ends December 31, 2026.

That letter is different from the Annual Notice of Change (ANOC) most members get every fall. The ANOC says, "here's what's changing in your plan next year." The non-renewal letter says, "this plan is going away." If you have the second kind, you are in the group this article is about.

The 27 plans not returning in King County, listed alphabetically by carrier:

• Aetna (CVS Health): Aetna Medicare Signature Advantage (HMO)
• Centene (WellCare): Wellcare Dual Access Open (PPO D-SNP); Wellcare Dual Liberty Sync Open (PPO D-SNP); Wellcare Dual Reserve (HMO-POS D-SNP); Wellcare Giveback (HMO-POS); Wellcare Patriot Giveback Open (PPO); Wellcare Simple (HMO-POS)
• Elevance Health (Anthem): Wellpoint Dual Advantage (HMO D-SNP); Wellpoint Full Dual Advantage (HMO D-SNP)
• Humana: Humana Gold Plus H5619-059 (HMO); Humana Gold Plus SNP-DE H1036-324 (HMO D-SNP); Humana Gold Plus SNP-DE H5619-167 (HMO D-SNP); Humana Together in Health (PPO I-SNP); HumanaChoice H5216-426 (PPO); HumanaChoice H7617-019 (PPO)
• Molina Healthcare of Washington, Inc.: Molina Medicare Complete Care Select (HMO D-SNP)
• Regence BlueShield: Regence MedAdvantage + Rx Primary (PPO)
• UnitedHealthcare: AARP Medicare Advantage Access from UHC WA-11 (PPO); AARP Medicare Advantage from UHC WA-0002 (PPO); AARP Medicare Advantage from UHC WA-0004 (PPO); AARP Medicare Advantage from UHC WA-0010 (HMO-POS); AARP Medicare Advantage from UHC WA-12 (PPO); AARP Medicare Advantage from UHC WA-16 (PPO); AARP Medicare Advantage Patriot No Rx WA-MA01 (PPO); UHC Complete Care WA-13 (HMO-POS C-SNP); UHC Dual Complete WA-S5 (PPO D-SNP); UHC Dual Complete WA-S6 (HMO-POS D-SNP)

If your plan name is not on that list, your plan is renewing — read the ANOC your insurer sent to see what's changing.

What happens if you do nothing

If your plan is on the non-renewing list and you make no choice by December 31, 2026, your Medicare Advantage enrollment ends. On January 1, 2027 you will be in Original Medicare — Part A (hospital) and Part B (doctor and outpatient) — directly through the federal government.

Two things to know about that default:

• Original Medicare does not include prescription drug coverage. If you need Part D, you have to enroll in a stand-alone drug plan.
• Original Medicare does not cap your out-of-pocket costs the way a Medicare Advantage plan does. Many people pair it with a Medigap (Medicare Supplement) policy to help with the share Medicare doesn't pay.

Doing nothing is a real option — some people prefer Original Medicare — but it should be an active choice, not something that just happens.

Your Special Enrollment Period

Because your plan is being discontinued, Medicare gives you a Special Enrollment Period (SEP) that extends past the usual Annual Enrollment deadline. For a non-renewed Medicare Advantage plan, that SEP runs from December 8, 2026 through February 28, 2027. You can use it to:

• Join a different Medicare Advantage plan (with or without drug coverage), or
• Return to Original Medicare and add a stand-alone Part D plan.

You can also act during the regular Annual Enrollment Period, October 15 – December 7, 2026. A choice made in that window takes effect January 1, 2027. A choice made in January or February under the SEP takes effect the first of the following month.

There is also a program-level Medigap guaranteed-issue right for people whose Medicare Advantage plan is terminating. That means certain Medigap policies must be sold to you without medical underwriting, within a set window. Washington has its own Medigap rules on top of federal rules — for state-specific guidance, contact the Washington State Office of the Insurance Commissioner.

What to look at before you pick

For 2027, the King County lineup includes 18 new plans and 10 that have been renamed, along with the plans that are continuing. The table below lists every 2027 plan offered in the county so you can compare.

A few things worth checking before you decide:

• Are your doctors, hospitals and pharmacies in the new plan's network?
• Are your prescriptions on its drug list (formulary), and at what tier?
• Does the plan include the extras you use (dental, vision, hearing, transportation)?
• If you qualify for both Medicare and Medicaid, is the plan a Dual-Eligible Special Needs Plan (D-SNP) that fits your situation?

For 2027, the Part D out-of-pocket cap rises to $2,400 (up from $2,100 in 2026) and the Part D maximum deductible is $700 (up from $615 in 2026). CMS will announce the 2027 Part B premium, Part B deductible and IRMAA income brackets later in the fall.

The Medicare Plan Finder at medicare.gov lets you type in your ZIP code and prescriptions and see what each 2027 plan would cost you specifically.