Medicare Advantage

Seattle's Medicare Advantage Open Enrollment: What You Can Change by March 31

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 — If you enrolled in a Medicare Advantage plan during the fall Annual Enrollment Period and something about it isn't working — the pharmacy network, the doctors, the referral rules — you are not stuck with it until next fall. The Medicare Advantage Open Enrollment Period runs from January 1 through March 31, and it gives people already in a Medicare Advantage plan one more chance to make a change.

Seattle retirees have a second window to fix Medicare Advantage choices — it closes March 31

This is a quieter enrollment window than the fall one. It gets less attention, fewer mailers, fewer television ads. But for Seattle residents who realized in January that their new plan doesn't cover a specialist at UW Medicine, Swedish, or Virginia Mason the way they expected, it is the right time to act.

Who this window is for

The Medicare Advantage Open Enrollment Period is only for people who are already enrolled in a Medicare Advantage plan on January 1. If that's you, this period applies. If you are in Original Medicare only, this specific window is not for you — you would generally wait for the fall Annual Enrollment Period (October 15 – December 7) or qualify for a Special Enrollment Period.

What you can change between January 1 and March 31

According to CMS, if you are in a Medicare Advantage plan, during this window you can:

• Switch to a different Medicare Advantage plan (with or without drug coverage).
• Drop your Medicare Advantage plan and return to Original Medicare (Part A and Part B).
• If you return to Original Medicare, join a stand-alone Part D prescription drug plan.

You get one change during this window. Once you make it, that's your move for the period. Any change you make takes effect the first day of the month after the plan receives your request.

What you cannot do in this window

This period is narrower than the fall one. During January 1 – March 31 you generally cannot:

• Switch from Original Medicare to a Medicare Advantage plan for the first time.
• Join a stand-alone Part D plan if you are staying on a Medicare Advantage plan.
• Switch from one stand-alone Part D plan to another if you are in Original Medicare.

Those moves belong to the fall Annual Enrollment Period or to a Special Enrollment Period triggered by a life event, such as moving out of your plan's service area.

Why 2027 is a good year to look twice

A few program-level changes make it worth pulling out your plan documents again for 2027:

• Part D out-of-pocket cap: The cap is $2,100 in 2026 and $2,400 in 2027. Once you reach it, you pay nothing more for the rest of the calendar year on covered drugs. This cap applies whether your drug coverage comes through a Medicare Advantage plan or a stand-alone Part D plan.
• Part D maximum deductible: $615 in 2026 and $700 in 2027. Plans can set a lower deductible, but not higher.
• No more coverage gap: The old "donut hole" was eliminated in 2025. Part D now has three phases instead of four.
• Medicare Prescription Payment Plan: You can ask to spread your prescription costs across the calendar year in monthly payments instead of paying large amounts at the pharmacy counter. It doesn't lower the total, but it smooths the timing.
• IRMAA: Higher-income beneficiaries pay an income-related surcharge on Part B and Part D. For 2026, IRMAA begins above $109,000 in income for a single filer.

If your new plan's drug list (formulary) or pharmacy network doesn't match how you actually use care, this window is your chance to correct course.

Seattle and King County: how availability works

Medicare plan availability is set at the county level, not the city level. Seattle is in King County, where a broad set of Medicare Advantage plans and carriers is offered. That means most Seattle residents have real choices — different network styles (HMO, PPO), different drug coverage designs, and different extra benefits.

You can see the full, current list for your ZIP code using the Plan Finder at medicare.gov. That tool is the official source and is updated for the plan year.

How to decide whether to switch

Before you change anything, it helps to answer four questions:

1. Are my current doctors and preferred hospitals still in the plan's network for 2027? 2. Are my prescriptions on the plan's drug list, and at what tier? 3. Does the plan use the pharmacies I actually use (including mail order if you use it)? 4. What are the plan's rules for referrals, prior authorization, and out-of-network care?

Star Ratings, published by CMS, are one more data point. They rate plans on quality and member experience on a 1-to-5 scale. They are useful context, not a personal recommendation.