Medicare Advantage

Seattle's 2027 Medicare Advantage lineup adds 18 new plans: how to check one before Dec. 7

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 — When the Annual Enrollment Period opens on October 15, people on Medicare in Seattle will see something they could not pick last year: 18 Medicare Advantage plans that are brand new for 2027. They come from six carriers, and they sit alongside plans that are renewing from 2026. If you want to switch into one — or make sure you are not accidentally switched out of a plan you like — you have until December 7, 2026 to decide.

Seattle is in King County, where Medicare plan availability is set. According to the CMS Medicare Advantage Landscape Source Files, 18 of the 59 Advantage plans offered in the county for 2027 are new. Below is who is bringing them, what type they are, and how to check a new plan against your doctors and prescriptions before the deadline.

What "new for 2027" actually means

A new Medicare Advantage plan is one the carrier did not sell in King County for 2026 and is offering for the first time starting January 1, 2027. That matters for two practical reasons:

• There is no local track record to look up. CMS Star Ratings are based on past measurement years, so a brand-new plan simply does not have a rating yet. The carrier may have ratings on its other plans, but those do not transfer.
• The provider network, drug list (formulary) and benefits for 2027 are what you need to check — not what a similarly named plan did in another market.

A renewing plan, by contrast, has a 2026 history: your current doctors are either in it or not, your drugs are either on the formulary or not, and you likely received an Annual Notice of Change (ANOC) in September describing what is different for 2027.

Who is adding plans in Seattle for 2027

The full table below lists every new plan. In alphabetical order by carrier:

• Aetna (CVS Health) — 2 new plans: Aetna Medicare Chronic Care (HMO C-SNP) and Aetna Medicare Eagle (HMO). Both include drug coverage. The C-SNP is a Chronic Condition Special Needs Plan.
• Devoted Health — 6 new plans: DEVOTED C-SNP ENHANCED 003 WA (HMO C-SNP), DEVOTED C-SNP GIVEBACK EXTRAS 004 WA (HMO C-SNP), DEVOTED C-SNP PLUS 005 WA (HMO C-SNP), DEVOTED CORE 001 WA (HMO), DEVOTED GIVEBACK 002 WA (HMO), and DEVOTED GIVEBACK EXTRAS 022 WA (HMO). Devoted is new to the King County market this year; all six plans include drug coverage.
• Elevance Health (Anthem) — 3 new plans, all Dual Eligible Special Needs Plans for people with both Medicare and Medicaid: Wellpoint Dual Advantage (HMO D-SNP), Wellpoint Dual Advantage Plus (HMO D-SNP), and Wellpoint Full Dual Advantage (HMO D-SNP).
• Molina Healthcare of Washington, Inc. — 1 new plan: Molina Medicare Elect (HMO D-SNP), with drug coverage.
• Regence BlueShield — 1 new plan: Regence BlueAdvantage HMO (HMO), with drug coverage. Regence's other 2026 Seattle plans were PPOs; this is the carrier's HMO offering.
• UnitedHealthcare — 5 new plans: AARP Medicare Advantage from UHC WA-18 (PPO), AARP Medicare Advantage Patriot No Rx WA-MA02 (HMO-POS), AARP Medicare Advantage Patriot No RX WA-MA3 (PPO), UHC Complete Care Support WA-1A (HMO-POS C-SNP), and UHC Complete Care Support WA-3A (HMO-POS C-SNP).

All 18 new plans include Part D drug coverage. The mix includes standard HMO, HMO-POS and PPO plans, plus Chronic Condition SNPs (C-SNPs) and Dual Eligible SNPs (D-SNPs). SNPs have eligibility rules — a C-SNP generally requires a qualifying diagnosis, and a D-SNP requires having both Medicare and Medicaid.

How to vet a new plan before December 7

Because a new plan has no local history, your check needs to be hands-on. A short routine that works:

1. Pull up the plan on Medicare Plan Finder. Go to medicare.gov, enter your ZIP code, and search 2027 plans. Each new plan listed above will appear with its benefits, formulary and provider directory for 2027. 2. Enter your prescriptions. The Plan Finder shows whether each drug is on the plan's formulary, what tier it is on, and what your projected yearly out-of-pocket cost would be. 3. Check your doctors and hospitals. Click into the plan and look up each provider by name. If a provider is central to your care, call their office and ask directly whether they will be contracted with that plan for 2027 — directories update throughout the year. 4. Read the Summary of Benefits. For a brand-new plan, this is the only "official" document describing 2027 coverage. There is no ANOC because there is no 2026 version to compare to. 5. If you have Medicaid or a qualifying condition, confirm you meet the SNP eligibility rules before enrolling.

Key 2027 figures to keep in mind

A few program-level numbers CMS has already set for 2027 will apply no matter which plan you pick:

• The Part D out-of-pocket cap is $2,400 in 2027, up from $2,100 in 2026.
• The Part D maximum deductible is $700 in 2027, up from $615 in 2026.
• The Part D national base beneficiary premium is $41.33 for 2027 — a formula input, not what any specific plan charges.

The 2027 Part B standard premium, Part B deductible and IRMAA income brackets have not been announced yet; CMS typically publishes those in the fall, usually November.

What happens if you do nothing

If you are enrolled in a 2026 plan that is renewing for 2027, you do not have to do anything — your plan will continue, with the changes described in your ANOC. If your current plan is one of the 27 in King County that is not returning for 2027, your carrier will send a non-renewal notice and you will have a Special Enrollment Period to pick a new plan. Either way, the AEP window of October 15 through December 7, 2026 is your chance to compare and switch for a January 1, 2027 start date.