Medicare Supplement

Medigap in Seattle: how Washington's standardized letters actually fit together

SEATTLE — If you have Original Medicare and you're looking at a Medicare Supplement policy in Seattle, the first thing to know is that these plans come in standardized versions labeled by letter. That means a Plan G from one company covers the same federally required benefits as a Plan G from another. What can differ is the price, the customer service, and — importantly in Washington — the rules that shape when you can switch.

Medicare SupplementSeattle, WA

What Medigap does (and doesn't) do

Medigap is private insurance that helps pay some of the out-of-pocket costs that Original Medicare leaves behind — things like the Part A hospital deductible, coinsurance, and copays. It only works with Original Medicare. If you're enrolled in a Medicare Advantage plan, you can't also use a Medigap policy.

Medigap also does not include prescription drug coverage. To get drug coverage, you pair Medigap with a stand-alone Part D plan. In 2026, Part D has a $2,100 out-of-pocket cap and a maximum deductible of $615. The old coverage gap ("donut hole") ended in 2025, so there are now three payment phases. If your drug costs are uneven month to month, the new Medicare Prescription Payment Plan lets you spread them out.

The standardized letters you can buy in Washington

Federal law standardizes Medigap plans across most states, including Washington. (Massachusetts, Minnesota and Wisconsin do things differently.) Each letter is a fixed benefit package.

For people who became eligible for Medicare on or after January 1, 2020, these letters are available:

• A, B, D, G, G-HD, K, L, M, and N

Plans C and F are closed to newer enrollees because they covered the Part B deductible, and federal law no longer allows new plans to do that. If you were eligible for Medicare before January 1, 2020, you may still be able to buy C or F.

The "HD" in Plan G-HD stands for high deductible: you pay more out of pocket up front in exchange for a lower premium. Plans K and L cap your yearly out-of-pocket costs but cover a smaller share of some services. Plan N has some copays for office and emergency room visits.

Because the benefits are set by letter, a Plan G is a Plan G no matter who sells it. What varies from insurer to insurer is what they charge and how their rates change over time.

How Medigap is priced — and why it matters in Seattle

Insurers can use one of three pricing methods:

• Community-rated — everyone pays the same, regardless of age.
• Issue-age-rated — your premium is based on the age you were when you bought the policy.
• Attained-age-rated — your premium goes up as you get older.

Two policies with the same letter can cost very different amounts over 10 or 20 years depending on which method the insurer uses. Ask before you sign. The Washington Office of the Insurance Commissioner publishes a Medigap rate guide that can help you compare.

Washington's switching rules

Federally, your strongest right to buy any Medigap plan sold in your area — with no medical underwriting — is during the six-month Medigap Open Enrollment Period that starts when you're 65 or older and enrolled in Part B. After that window, insurers in most states can ask health questions.

Washington has additional consumer protections that can make it easier to switch Medigap plans later on. Because these rules change and depend on your situation, don't rely on a summary — call the state's SHIP (Statewide Health Insurance Benefits Advisors, known locally as SHIBA) or the Washington Office of the Insurance Commissioner before you make a move.

How to find the policies sold in your ZIP code

There isn't a single public list of every Medigap insurer in Seattle we can print here, but there are three reliable ways to see what's available to you:

1. Medicare.gov's Medigap policy search — enter your ZIP code to see the plans and insurers offered in King County. 2. Washington's Medigap rate guide — the state insurance department publishes side-by-side pricing information. 3. SHIBA (Washington's SHIP) — free, unbiased counseling from trained volunteers.