Medicare Open Enrollment 2027 in Washington: Dates, Changes and Your Medigap Rights

Medicare open enrollment for 2027 coverage runs from Thursday, October 15, through Monday, December 7, 2026. Whatever you choose takes effect January 1, 2027. If you choose nothing, you generally keep your coverage, and any changes your plan made to its costs or benefits start January 1 anyway.

That last part is what people miss. Doing nothing means accepting your plan's 2027 terms, and those terms should already be in your mail: federal rules required plans to send the Annual Notice of Change so it reached you by September 30.

Below: what you can and can't change this fall, the government-set numbers that move on January 1, the separate January-to-March window for Medicare Advantage members, and Washington's Medigap switching rule, read from the statute.

Source: CMS, September 28, 2026; CMS 2027 Rate Announcement; CMS 2027 state fact sheets.

What you can change between October 15 and December 7

Medicare.gov lists three kinds of moves for this window:

• Join, drop or switch to another Medicare Advantage plan, with or without drug coverage.
• Switch from Original Medicare to Medicare Advantage, or from Medicare Advantage back to Original Medicare.
• Join, drop or switch a Medicare drug plan (Part D) if you're in Original Medicare.

The plan has to get your request by December 7. You can enroll through the Medicare.gov Plan Finder, through the plan, or by calling 1-800-MEDICARE. If you're happy where you are, CMS says you generally do not need to re-enroll.

What this window doesn't do:

• Late Part B sign-up. If you skipped Part B and don't qualify for a Special Enrollment Period, your window is the General Enrollment Period, January 1 to March 31, and a late penalty may apply.
• Medigap without health questions. Medigap runs on separate rules: the federal six-month Medigap Open Enrollment Period that starts the first month you have Part B and are 65 or older, plus Washington's replacement rule below.
• Shield you from the Part D late penalty. Move to a Medicare Advantage plan without drug coverage, or drop a drug plan, and you can owe a Part D late enrollment penalty once you've gone 63 or more days in a row without creditable drug coverage.

That penalty sticks, so see the math. It's 1% of the national base beneficiary premium times your full uncovered months, rounded to the nearest 10 cents and added to your monthly premium, generally for as long as you have Medicare drug coverage. Example: at CMS's 2027 base of $41.33, 20 uncovered months is 1% × $41.33 × 20 = $8.27, rounded to $8.30 a month. The base resets every year, so the penalty can rise with it. If you get Extra Help, you don't pay a Part D late enrollment penalty (Medicare & You 2027).

The 2026–2027 calendar

Most of these dates are set by federal regulation. The last row is Washington-only.

Source: 42 CFR 422.2267; CMS 2027 state fact sheets; Medicare & You 2027; Medicare.gov Special Enrollment Periods; Medicare.gov coverage start dates; RCW 48.66.045.

What changes on January 1, 2027

These are the numbers Medicare sets. The cap and the deductible limit apply to every Medicare drug plan, standalone or built into a Medicare Advantage plan. (Basics on drug coverage: our Washington Part D page.)

Source: CMS CY2027 Rate Announcement, Table V-2; Medicare.gov Part D costs; Medicare.gov insulin; Medicare.gov Extra Help; CMS negotiated prices fact sheet; Medicare & You 2027.

The cap. Once your out-of-pocket spending on covered Part D drugs reaches $2,400, you move into catastrophic coverage and pay nothing out of pocket for covered Part D drugs for the rest of the year. Payments made for you through Extra Help count toward it. Drugs bought with a discount card instead of your Medicare coverage don't, which is new language in the 2027 handbook.

Negotiated prices. Medicare-negotiated prices for 15 more Part D drugs start January 1, 2027, on top of the first 10 from 2026. CMS projected people with Medicare drug coverage would pay an estimated $685 million less out of pocket under the standard benefit design. CMS also lists four first-round drug entries leaving the negotiated list on January 1, 2027, after CMS deselected them (typically because of generic or biosimilar competition). If you take a first-round drug, check its 2027 cost in Plan Finder instead of assuming.

Standalone drug plans. CMS is ending a temporary premium demonstration for standalone drug plans at the end of 2026, returning to traditional market conditions in 2027. I won't guess what that does to any plan. It's a reason to read the premium line on your notice.

Part B. As of October 11, 2026, CMS hadn't announced the 2027 Part B premium or deductible; the 2026 figures came out November 14, 2025. For 2026 the standard premium is $202.90 a month and the deductible is $283.

Read your Annual Notice of Change before you shop

Medicare & You 2027 says the ANOC covers any changes in coverage, costs, provider networks, service area, and more that will be effective in January. The Evidence of Coverage, or a notice of where to find it, is due by October 15. If nothing has arrived by October 15, the Office of the Insurance Commissioner says to contact your insurance company and ask. The OIC's Medicare Jumpstart Toolkit includes a fill-in form for charting what's changing.

Source: Medicare & You 2027; WA OIC open enrollment page; Medicare.gov joining a plan; Medicare.gov Prescription Payment Plan; 42 CFR 423.137.

My suggestion: start with the drug list. A premium change is easy to spot. A drug moving tiers, or your pharmacy losing preferred status, can cost more and doesn't jump off the page.

How to use the Medicare.gov Plan Finder

CMS loaded 2027 plan information into Plan Finder by October 1. It estimates your yearly drug costs for each plan if you give it the details. The order that works:

1. Log in (Login.gov, ID.me or CLEAR) so your information is saved.
2. Enter your ZIP code.
3. Add every prescription you take regularly, with the dose.
4. Pick the pharmacies you actually use; preferred versus standard cost sharing changes the price.
5. Check your doctors and pharmacies are in network. Plan Finder can save providers; call the offices too.
6. Compare premium, deductibles and estimated yearly drug cost together, not the premium alone.
7. If you spend part of the year in another state, check coverage there.
8. Enroll through Plan Finder, the plan, or 1-800-MEDICARE by December 7.

If you believe you chose the wrong plan because of inaccurate or misleading information, including from Plan Finder, Medicare.gov says to call 1-800-MEDICARE and explain. How the parts of Medicare fit together is on our Washington Medicare overview.

January 1 to March 31: the second window, for Medicare Advantage only

The Medicare Advantage Open Enrollment Period runs January 1 to March 31, 2027, for people already in Medicare Advantage. You get one change: switch to another Medicare Advantage plan, or drop Medicare Advantage and return to Original Medicare, adding a separate drug plan if you want one. It doesn't let you move from Original Medicare into Medicare Advantage or change drug plans if you're in Original Medicare. A change takes effect the first of the month after the plan gets your request.

If you joined Medicare Advantage when first eligible at 65, or dropped Medigap to try Medicare Advantage for the first time, you can return to Original Medicare within 12 months and have special rights to buy a Medigap policy for a limited time.

Before leaving Medicare Advantage, read the next section. Returning to Original Medicare is one decision. Getting a Medigap policy alongside it is another.

Washington's Medigap switching rule, read from the statute

RCW 48.66.045(2) requires every Medigap insurer covering Washington residents to issue certain standardized plans without evidence of insurability when the new policy replaces another Medicare supplement policy. That means no health questions and no medical underwriting. The statute sets no enrollment window, and the OIC says Plan B through N holders can switch at any time to another Medigap plan B through N. It isn't tied to any yearly window. It is tied to the plan you have and when you became eligible:

Source: RCW 48.66.045; WAC 284-66-064; WA OIC Medigap page.

The limits, from the text:

• You generally need Medigap already. The statute covers a policy that replaces another medicare supplement policy or certificate or other more comprehensive coverage. Coming from anything else, the OIC says rules can vary and insurers may require you pass a written health screening questionnaire. Its hotline (800-562-6900) can connect you with a health compliance analyst.
• Plan A is a closed loop. The only guaranteed switch for Plan A holders is to another Plan A (RCW 48.66.045(2)(c)); moving up can mean health questions.
• Only letters the new insurer sells. The insurer must issue its standardized plans from the list, so you choose among the letters it offers.
• Under 65 counts. The rule covers residents eligible by age, disability or end-stage renal disease. Buying a first policy under 65 is different; the OIC warns you might not get the plan you want, or any Medigap plan, until 65.
• No new waiting period. Under WAC 284-66-170, if your old policy was in effect at least three months, the new one can't impose pre-existing condition or waiting periods.
• Community rating. RCW 48.66.045(3) requires one premium for everyone on the same standardized plan form, except spousal discounts, payment frequency and method, and up to two rating pools (age vs. disability or ESRD).

Two 2025 bills would have widened this: HB 1603 (guaranteed Medigap when leaving Medicare Advantage during an open enrollment period) and HB 1754 (guaranteed issue during Medicare open enrollment periods from 2027). Neither advanced out of committee: as of October 11, 2026, the Legislature's pages for HB 1603 and HB 1754 show a February 2025 hearing in the House health care committee and no action since, beyond being carried into the 2026 session.

What this means for the fall: with Medigap, you don't need to squeeze a Medigap change into October through December, because the right works any month. Your open enrollment job is the drug plan beside it. And if you're thinking of dropping Medigap for Medicare Advantage, Medicare & You 2027 warns you may not get the same policy back, or in some cases any Medigap policy, outside your trial right. Most Medigap policies don't cancel automatically when you join Medicare Advantage, and it's illegal to sell you Medigap while you're in Medicare Advantage unless you're switching back. More on our Washington Medicare Supplement page.

How many Washingtonians are in Medicare Advantage

CMS counts 1,583,566 people on Medicare in Washington. KFF looks at the narrower group with both Part A and Part B (the people who can choose Medicare Advantage): in March 2026, 54% of them in Washington were in Medicare Advantage, a little under the national 55%.

Medicare Advantage54.0%Not in Medicare Advantage46.0%

Source: KFF, Medicare Advantage in 2026: Enrollment Update and Key Trends

Show the numbers

Coverage	Share
Medicare Advantage	54.0%
Not in Medicare Advantage	46.0%

Clark County74.2%Snohomish County66.5%Spokane County62.0%King County60.0%Pierce County57.2%Thurston County56.9%Washington statewide54.0%Whatcom County50.4%Yakima County49.5%Skagit County47.4%Kitsap County44.0%Benton County34.7%Clallam County24.2%

Source: KFF county data, March 2026

Show the numbers

County	In Medicare Advantage
Clark County	74.2%
Snohomish County	66.5%
Spokane County	62.0%
King County	60.0%
Pierce County	57.2%
Thurston County	56.9%
Washington statewide	54.0%
Whatcom County	50.4%
Yakima County	49.5%
Skagit County	47.4%
Kitsap County	44.0%
Benton County	34.7%
Clallam County	24.2%

Where you live changes the picture. Clark County, across the Columbia from Portland, is at 74.2%; Snohomish 66.5%; King 60.0%. Whatcom is about half (50.4%), and Clallam, on the Olympic Peninsula, is 24.2%. These shares aren't a verdict on either path. They do show how many people in each county would face the Medigap question above if they moved back to Original Medicare.

Extra Help and Medicare Savings Programs

Extra Help lowers Part D costs for people with limited income and resources. Medicare.gov's 2026 limits: annual income below $23,940 (individual) or $32,460 (married couple), and resources below $18,090 ($36,100 for a couple), a limit that already includes up to $1,500 per person set aside for burial (CMS). Your home, one car, a burial plot and household items don't count. 2027 limits weren't posted as of October 11. With Extra Help in 2027 you pay at most $5.80 per generic and $14.40 per brand-name drug, and nothing for covered drugs once total drug costs reach $2,400. Apply through Social Security (1-800-772-1213).

Washington's Medicare Savings Programs, run by the Health Care Authority, help with Medicare premiums and, for QMB, cost sharing. HCA says there's no asset test, and CMS says anyone enrolled in a Medicare Savings Program automatically qualifies for Extra Help.

Source: Washington HCA, Apple Health income and resource standards, October 1, 2026; HCA Medicare Savings Program page; CMS, September 28, 2026. HCA's flyer shows the same limits $20 lower, after the $20 is deducted.

With Extra Help or Apple Health (Washington's Medicaid), you aren't limited to the fall and winter windows. Since January 1, 2025, you can change once a month, but only into Original Medicare with a standalone drug plan, or between standalone drug plans. People with full Apple Health coverage also have a monthly option for certain integrated Medicare-Medicaid plans (CMS job aid).

Calls, texts and "Medicare is calling"

The OIC's advice: If a caller claims to be from Medicare, hang up. Medicare won't call to verify your Medicare number or enroll you in a plan. Under 42 CFR 422.2264 and 423.2264, Medicare Advantage and Part D plans and their agents can't cold call, robocall, text or leave voicemails unless you asked to be contacted or you're already a member of the plan, and can't show up at your door uninvited. Per Medicare.gov, they can't charge an enrollment fee, offer you cash to join, or give gifts worth more than $15. You can check any agent's Washington license with the OIC lookup tool. Report suspicious contact to 1-800-MEDICARE or to SHIBA, which runs Washington's Senior Medicare Patrol project, at 1-800-562-6900.

Unbiased help in Washington

SHIBA (Statewide Health Insurance Benefits Advisors), run by the Office of the Insurance Commissioner, uses trained volunteers to give free, unbiased and confidential Medicare help, including comparing plans and switching during open enrollment. Call 1-800-562-6900 (8:30 a.m. to 4:30 p.m., Monday to Friday; TDD 360-586-0241) and ask for your local SHIBA office. 1-800-MEDICARE (1-800-633-4227; TTY 1-877-486-2048) is open 24 hours a day.

Whoever you talk to, bring your ANOC and a list of every drug you take, with doses.

FAQ

When is Medicare open enrollment for 2027?

October 15 through December 7, 2026. The plan must get your request by December 7, and changes take effect January 1, 2027. To keep your current coverage, you generally don't need to re-enroll.

What is the Medicare Part D out-of-pocket cap in 2027?

$2,400, up from $2,100 in 2026. Once your out-of-pocket spending on covered Part D drugs reaches it, you pay nothing out of pocket for covered Part D drugs for the rest of the year.

Can I switch Medigap plans at any time in Washington?

Yes, if you already have Medigap. Under RCW 48.66.045, insurers must issue a replacement policy without health questions, with no yearly window: Plan B through N to another B through N (C, F and high-deductible F only if eligible before 2020), and Plan A to Plan A. Coming from Medicare Advantage, insurers may require health questions unless another guaranteed-issue right applies.

Can I switch from Medicare Advantage back to Original Medicare?

Yes, during open enrollment (October 15 to December 7), or once from January 1 to March 31 if you're in Medicare Advantage. A Medigap policy at that point may require health questions in Washington unless a guaranteed-issue right applies.

Where can I get unbiased Medicare help in Washington?

SHIBA, the Insurance Commissioner's Statewide Health Insurance Benefits Advisors program, at 1-800-562-6900 (8:30 a.m. to 4:30 p.m., Monday to Friday), or 1-800-MEDICARE, open 24 hours a day.

Your own plan documents and Washington and federal law control. Confirm your situation with a licensed agent, SHIBA, the Washington Office of the Insurance Commissioner, or, for legal questions, an attorney.

Sources

1. CMS press release: Medicare Advantage and Part D programs for 2027 (Sept 28, 2026)
2. CMS: 2027 Medicare Advantage and Part D state-by-state fact sheets
3. CMS: CY2027 Rate Announcement (Apr 6, 2026)
4. CMS: Part D 2027 national average bid and base beneficiary premium (Jul 28, 2026)
5. CMS: negotiated prices for 2027 fact sheet
6. CMS: selected drugs and negotiated prices
7. CMS: 2026 Medicare Parts A and B premiums and deductibles (Nov 14, 2025)
8. CMS: dual and Extra Help Special Enrollment Periods job aid
9. Medicare & You 2027 handbook
10. Medicare.gov: joining a plan
11. Medicare.gov: Special Enrollment Periods
12. Medicare.gov: when Medicare coverage starts
13. Medicare.gov: Part D costs and late enrollment penalty
14. Medicare.gov: insulin
15. Medicare.gov: Medicare Prescription Payment Plan
16. Medicare.gov: Extra Help with drug costs
17. Medicare.gov: plan marketing rules
18. eCFR: 42 CFR 422.2267 (required materials, ANOC timing)
19. eCFR: 42 CFR 422.2264 (contact with beneficiaries, Medicare Advantage)
20. eCFR: 42 CFR 423.2264 (contact with beneficiaries, Part D)
21. eCFR: 42 CFR 423.137 (Medicare Prescription Payment Plan, automatic renewal)
22. RCW 48.66.045: mandated coverage for replacement policies
23. WAC 284-66-064: benefit standards for policies issued on or after June 1, 2010 (subsection (4), replacement policies)
24. WAC 284-66-170: waiting periods on replacement policies
25. Washington Legislature: HB 1603 (2025-26) status
26. Washington Legislature: HB 1754 (2025-26) status
27. WA OIC: Medigap coverage and costs
28. WA OIC: Medicare open enrollment
29. WA OIC: get ready for Medicare open enrollment (Jumpstart Toolkit)
30. WA OIC: free, unbiased Medicare help from SHIBA
31. WA OIC: how SHIBA can help
32. WA OIC: identify and report Medicare fraud
33. WA OIC / SHIBA: Medicare fraud during open enrollment fact sheet (Oct 2025)
34. WA OIC: agent and company lookup
35. Washington HCA: Medicare Savings Program
36. Washington HCA: Apple Health income and resource standards (Oct 1, 2026)
37. KFF: Medicare Advantage in 2026, enrollment update and key trends
38. KFF: county-level Medicare Advantage data (March 2026)