Washington has roughly 1.4 million Medicare enrollees, with about 42% currently on Medicare Advantage — a lower MA share than the national average and well below states like Florida or Alabama.1 That reflects the market structure: King, Snohomish, and Pierce counties have deep competitive MA markets, while many rural Eastern Washington counties have only one or two Advantage plans available.

What Medicare covers, and what it doesn’t

Medicare is health insurance. It is not long-term-care insurance. The most expensive misconception in caregiving, and especially common in Washington where adult children of out-of-state parents assume Medicare will pay for in-home aide hours or memory care. It will not.

What Medicare does cover:

What Medicare does not cover:

Original Medicare vs. Medicare Advantage in Washington

Every Medicare-eligible person chooses between two broad structures: Original Medicare (Parts A and B, usually with a Medigap supplement and a Part D drug plan) or Medicare Advantage (Part C, a private plan that bundles A, B, and usually D plus extras). Washington’s split is roughly 58% Original / 42% Advantage in 2025.2

The geography matters. In King, Snohomish, and Pierce counties, 40+ Advantage plans typically compete — plenty of $0-premium options with rich extras. In rural counties like Garfield, Ferry, Pend Oreille, and parts of Okanogan, two or three plans is the norm. The Advantage choice can be much better in metro Western Washington than in Eastern Washington, simply because of the competition.

When Original Medicare + Medigap usually beats Advantage

When Advantage usually beats Original Medicare

Medigap in Washington

If your parent chooses Original Medicare, a Medigap policy covers the deductibles and coinsurance that Original Medicare leaves behind. Medigap plans are federally standardized— Plan G in Washington offers the same benefits as Plan G anywhere — but Washington has specific rating and enrollment rules:

Apple Health Medicare Savings Programs (MSPs)

Washington dual-eligibles — people with both Medicare and Apple Health — can have Medicare costs paid by the state through MSPs. Three tiers:3

Many Washington seniors who qualify never apply because the application is opaque and outreach is limited. A SHIBA counselor can walk your parent through the process for free.

Annual Enrollment Period (AEP) in Washington

Medicare AEP runs from October 15 through December 7 each year. During this window your parent can:

Washington’s AEP marketing is lighter than in heavily- retired states like Florida or Arizona, but Seattle metro still sees significant television and direct-mail spend. The right comparison tool is Medicare.gov’s Plan Finder, which lets you enter your parent’s ZIP code, prescriptions, and preferred providers, then ranks every plan by total annual cost.4

A Medicare Advantage Open Enrollment Period (MA OEP) runs January 1 through March 31 each year — a second chance for someone already on Advantage to switch or move back to Original Medicare with Part D.

Where to get free help in Washington

SHIBA(Statewide Health Insurance Benefits Advisors) is Washington’s federally-funded State Health Insurance Assistance Program (SHIP), operated by the Office of the Insurance Commissioner. Volunteers across every Washington county provide free, unbiased Medicare counseling — they don’t sell plans, take commissions, or represent any insurer. Call 1-800-562-6900 or visit insurance.wa.gov/shiba.

For Medicaid-related questions where Medicaid and Medicare interact (dual-eligibility, LTC benefits), see our Washington Apple Health guide.