Enrollment periods

When Can I Change My Medicare Plan in Washington?

Most changes to Medicare Advantage and Part D plans happen in set windows: the Annual Enrollment Period (October 15 to December 7), the Medicare Advantage Open Enrollment Period (January 1 to March 31) and special enrollment periods for life events, such as your plan ending, a move or getting Apple Health. Medigap works differently: in Washington, once you have a Medigap policy, you can switch Medigap plans at any time of year without health questions (RCW 48.66.045).

By the Benefits Life Editorial Team, licensed insurance agents · Reviewed November 9, 2026

The complete enrollment calendar

Window	When	What you can do
Initial Enrollment Period	7 months around the month you turn 65	First sign-up for Parts A and B, and for a Medicare Advantage or Part D plan
Annual Enrollment Period	October 15 to December 7	Switch Medicare Advantage or Part D plans, join or leave Medicare Advantage; changes start January 1
Medicare Advantage Open Enrollment Period	January 1 to March 31	If you're in Medicare Advantage: one change, to another Medicare Advantage plan or to Original Medicare plus Part D
General Enrollment Period	January 1 to March 31	Sign up for Part A and/or Part B if you missed your Initial Enrollment Period; coverage starts the month after you sign up
Special enrollment periods	Triggered by events	Depends on the event; see below
Plan not renewed	December 8 to the last day of February	Choose a new Medicare Advantage or Part D plan if yours isn't renewed
5-star plan	Once between December 8 and November 30	Switch to a plan with a 5-star overall rating, if one is offered in your area
Medigap open enrollment	6 months starting the first month you're 65 or older and have Part B	Buy any Medigap policy a company sells, with no health review
Medigap guaranteed-issue rights	Triggered by events, usually until 63 days after other coverage ends	Buy certain Medigap plans with no health review
Washington Medigap switch	Any time, if you already have Medigap	Switch Medigap plans (Plan A to Plan A, or any other plan to Plan B through N) with no health questions

The Washington Medigap any-time switching right

Washington has no Medigap birthday rule. Instead, under state law (RCW 48.66.045 and WAC 284-66-064(4)), a Medigap company must sell you its policy without evidence of insurability when it replaces your current Medigap policy, on any day of the year:

If you have Plan A, you can switch to another company's Plan A.
If you have any other plan, you can switch to a company's Plan B, D, G, high-deductible G, K, L, M or N (and C, F or high-deductible F if you were eligible for Medicare before 2020). You can change letters, such as Plan G to Plan N.
The law sets no waiting time before you can switch. If your current policy has been in effect at least 3 months, the new one can't impose a waiting period for pre-existing conditions (RCW 48.66.130; WAC 284-66-170).
The right covers only plans the new company sells in Washington.

Why it matters: when your premium goes up, you can compare companies and change at any time instead of waiting for a yearly window. How to use it: apply to the new company, wait for written approval and a start date, then cancel your old policy so the coverage doesn't overlap. Coming from Medicare Advantage or another kind of plan is different; see Medigap in Washington.

Annual Enrollment Period: October 15 to December 7

The biggest yearly window. It is open now for 2027 coverage. During it you can:

Switch from one Medicare Advantage plan to another
Switch from Original Medicare to Medicare Advantage
Switch from Medicare Advantage back to Original Medicare
Switch from one Part D plan to another
Join or drop Part D coverage

Changes take effect January 1. Keep your confirmation number, and check that your medications and providers are covered by the new plan for the coming year before you enroll.

Full open enrollment guide for Washington

Medicare Advantage Open Enrollment Period: January 1 to March 31

If you're in a Medicare Advantage plan on January 1, you get one more change:

Switch to a different Medicare Advantage plan, or
Drop Medicare Advantage and return to Original Medicare, and join a standalone Part D plan

What you can't do in this window: switch from Original Medicare to Medicare Advantage, or switch between standalone Part D plans if you have Original Medicare. Those need the Annual Enrollment Period or a special enrollment period.

Changes take effect the first day of the month after the plan gets your request.

If your plan is ending in 2027

Many Washington Medicare Advantage plans end December 31, 2026. CMS data shows some companies are leaving and some plans aren't being renewed. If yours is one of them, you can pick new coverage during the Annual Enrollment Period through December 7 or a special enrollment period to February 28, 2027; choose by December 31 so coverage starts January 1. If you choose during the Annual Enrollment Period, that special enrollment period no longer applies to you. You also have a guaranteed right to buy certain Medigap policies until 63 days after the plan ends. See Washington plans ending in 2027.

Special enrollment periods: qualifying life events

Outside the calendar windows, certain events give you a special enrollment period. Common ones in Washington:

Moving out of your plan's service area, or to a place with new plan options, or back to the U.S.: you generally have the month of the move plus 2 full months.
Losing other coverage, such as employer coverage ending.
Apple Health or Extra Help: once a month you can switch to a different Part D plan, or drop a Medicare Advantage plan with drug coverage and join a standalone Part D plan. If you have full Apple Health and Medicare, you can also join or switch to an integrated D-SNP once a month. See D-SNPs in Washington and Extra Help.
Your plan isn't renewed or leaves Medicare (see above).
A 5-star plan in your area: you can switch to it once between December 8 and November 30.
Wildfire or other declared disaster that kept you from making a choice: details here.
Other exceptional circumstances, such as being misled by a plan, or a significant change to a plan's provider network, which Medicare reviews case by case.

Medigap rules are different

Medigap doesn't follow the Annual Enrollment Period. You can buy Medigap without a health review:

During your 6-month Medigap open enrollment period, starting the first month you're 65 or older and enrolled in Part B (RCW 48.66.025)
During guaranteed-issue situations, such as your Medicare Advantage plan ending, employer coverage that pays after Medicare ending, or a 12-month trial right (RCW 48.66.055)
Under Washington's switching right, any time, if you already have Medigap (RCW 48.66.045)

Outside these situations, a company can review your health before selling you a first Medigap policy and may turn you down.

Common scenarios and which window applies

Your situation	Window
Just turned 65, new to Medicare	Initial Enrollment Period, then your Medigap open enrollment period if you want Medigap
Want to drop my Medicare Advantage plan and go back to Original Medicare	Annual Enrollment Period (Oct 15–Dec 7) or Medicare Advantage Open Enrollment Period (Jan 1–Mar 31)
My Medicare Advantage plan ends December 31, 2026	Annual Enrollment Period, or the non-renewal special enrollment period to February 28, 2027; Medigap guaranteed-issue right until 63 days after the plan ends
Moving from Seattle to Spokane	Special enrollment period for a move, if your plan doesn't serve Spokane County or there are new options there
My plan raised the cost of my medication for next year	Annual Enrollment Period (Oct 15–Dec 7), unless another window applies to you
Want a lower-premium Medigap policy than the one I have	Washington switching right: any time, no health questions
I delayed Part B because I was working; now I'm retiring	Special enrollment period for losing employer coverage; your Medigap open enrollment period starts when Part B starts
A doctor I've used for years left my Medicare Advantage plan	Usually the next Annual Enrollment Period or the Jan–Mar window, unless Medicare finds the network change significant or another special enrollment period applies

What you usually can't change mid-year

Getting a first Medigap policy mid-year usually means a health review, unless you have a guaranteed-issue right (switching between Medigap policies is open any time in Washington)
Switching from Original Medicare to Medicare Advantage mid-year requires a special enrollment period; the January–March window works only in the other direction
Provider network changes alone generally don't give you a special enrollment period, unless Medicare finds the change significant
Drug list changes during the year generally don't give you a special enrollment period, but your plan must give you advance written notice of many changes that affect a drug you take

Not sure which window applies? Call 1-800-MEDICARE (1-800-633-4227, TTY 1-877-486-2048), or call (206) SENIORS (206-736-4677), TTY 711 to reach a licensed insurance agent with Benefits Life, at no cost to you. To look at plans, see plans in your ZIP code.

Sources

Frequently asked questions

Can I change my Medicare plan anytime?

Not for Medicare Advantage or Part D. Those changes are limited to your Initial Enrollment Period, the Annual Enrollment Period (October 15 to December 7), the Medicare Advantage Open Enrollment Period (January 1 to March 31) or a special enrollment period. Medigap is different: in Washington, if you already have Medigap, you can switch Medigap plans at any time without health questions.

Does Washington have a Medigap birthday rule?

No. Washington has no birthday rule. Under RCW 48.66.045, if you have a Medigap Plan B through N, you can switch to another company's Plan B through N at any time without evidence of insurability; Plan A can be switched only to another Plan A. The law sets no waiting time to switch; the 3-month rule only affects waiting periods for pre-existing conditions.

Can I drop my Medicare Advantage plan mid-year?

If you're in a Medicare Advantage plan on January 1, you can make one change from January 1 to March 31: switch to another Medicare Advantage plan, or drop it for Original Medicare and join a standalone Part D plan. Outside that window and the Annual Enrollment Period, you generally need a special enrollment period.

My Medicare Advantage plan ends December 31, 2026. When can I choose a new one?

You can choose during the Annual Enrollment Period through December 7, and a special enrollment period for plans that aren't renewed lets you choose until February 28, 2027. Choose by December 31 to have coverage start January 1 with no gap. If you choose during the Annual Enrollment Period, you can't use that special enrollment period later. You also have a guaranteed right to buy certain Medigap policies until 63 days after your plan ends.

If I miss the Annual Enrollment Period, when can I change?

It depends on the change. If you're in Medicare Advantage, you can still switch plans or return to Original Medicare from January 1 to March 31. To move from Original Medicare to Medicare Advantage, you generally wait for the next Annual Enrollment Period or qualify for a special enrollment period. Washington Medigap policyholders can switch Medigap plans at any time.

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Licensed insurance agents for Washington

These independent insurance agents are licensed in Washington and work with Benefits Life, the publisher of this site. When they enroll you in a plan, the agent and Benefits Life may be paid by the insurance company. Learn more.