Your 2027 Guide to Medicare Advantage in Seattle, Washington

King County's Medicare Advantage lineup shifts for 2027: 18 new plans, 27 plans leaving and 21 plans changing, out of the 68 offered for 2026. Here's a plain-English look at how the plans work for people in Seattle, Washington and what to weigh — with no sales pitch.

Here's the Seattle picture in plain terms. Your county sets your Medicare options, and Seattle sits in King County (part of Seattle area) — so that's the lens for everything below.

59 Medicare Advantage plans are available for 2027. Roughly 54% of people with Medicare in the county have chosen Medicare Advantage over Original Medicare, among the roughly 320,899 residents who are 65 or older. Those are factual, area-level counts — we don't rank plans.

Expect the companies active locally, a jargon-free walkthrough of how Medicare works, the 2027 costs, the enrollment calendar, and free help when you want a person to talk to.

How your Medicare choices fit together

Almost everyone starts with Original Medicare — Part A (hospital) and Part B (medical), run by the federal government. From there, you generally choose one of two directions, and understanding the fork is the whole game.

The Medicare Advantage path (Part C). You get your Part A and Part B benefits through a private plan approved by Medicare, usually with drug coverage included. Plans work within networks and service areas set at the county level, which is why availability in Seattle, Washington depends on your county, not just your state.

The Original Medicare path. You stay with the government program and can add a stand-alone Part D drug plan, and often a Medigap policy to help with the out-of-pocket costs Original Medicare leaves behind — trading bundled extras for broad provider freedom.

Neither path is universally better; the right fit depends on your doctors, your prescriptions, your budget, and how you like to handle care. This guide explains how each works in Seattle, Washington so you can decide for yourself. We don't rank or recommend specific plans.

What Medicare costs in 2027

It helps to separate the costs everyone shares from the costs that vary by plan. The program-level numbers here are set nationally — the same whether you're in a big city or a rural county.

Part B premium. Most people pay the standard Part B premium of $202.90 a month in 2026 (2026 amount; 2027 figure will be posted when CMS releases it). Part A is premium-free for most people who worked and paid Medicare taxes long enough.

Part D drug costs. In 2027, a Part D plan's yearly deductible can be no more than $700, and a $2,400 cap limits what you pay out of pocket for covered prescriptions across the year — a real change for anyone with high drug costs.

Higher earners pay more for Parts B and D through an income-related adjustment called IRMAA, which for 2026 starts above $109,000 in annual income for an individual and is based on your 2024 tax return. Most people fall below that line and pay the standard amounts. The 2027 brackets will be posted when CMS releases them.

Plan-specific costs. What an individual plan charges — its premium, deductible, copays, and what it covers — varies by plan and changes yearly. We don't publish those figures or rank plans; Medicare's Plan Finder shows the current details for your situation, and a licensed agent can walk you through them.

Your Medicare enrollment calendar

The dates that follow are set federally, so they don't change from state to state — only your personal timing does.

It starts with your Initial Enrollment Period — the 7-month window around your 65th birthday month — the window around turning 65 when you first sign up. Missing it can mean late penalties that stick around, so it's the one not to sleep on.

After that, the big recurring window is the Annual Enrollment Period (Open Enrollment), October 15 – December 7, when anyone can join, switch, or drop an Advantage or Part D plan for a January 1 start. And if you're already in an Advantage plan, the Medicare Advantage Open Enrollment (January 1 – March 31) gives you one more chance to change course.

Life events — a move, a loss of other coverage — can also trigger a Special Enrollment Period. The calendar below shows the whole year at a glance.

Getting unbiased help in Seattle

You never have to make these decisions alone, and you don't have to pay for good help. A few free, trustworthy starting points:

Medicare.gov and 1-800-MEDICARE (TTY 1-877-486-2048) are the official sources for plan details and the Plan Finder. Licensed agents can also compare options with you and handle enrollment.

And to be clear about who we are: MyMedicarePlans.org is a privately owned, independent educational resource. We are not Medicare, not a government agency, and not affiliated with one. We publish plain-language information to help you get oriented — then point you to the official sources and licensed professionals for decisions about specific plans.

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