Medicare in Washington by county

Most people with Medicare

Across Washington, 1,586,306 people had Medicare in July 2026, 50% of them in Medicare Advantage or another Medicare health plan. The counties with the most:

1. King County 368,813 with Medicare · 54% in Medicare Advantage · 22 Advantage plans with drug coverage
2. Pierce County 176,141 with Medicare · 52% in Medicare Advantage · 27 Advantage plans with drug coverage
3. Snohomish County 152,940 with Medicare · 60% in Medicare Advantage · 23 Advantage plans with drug coverage
4. Spokane County 123,249 with Medicare · 57% in Medicare Advantage · 18 Advantage plans with drug coverage
5. Clark County 108,542 with Medicare · 67% in Medicare Advantage · 25 Advantage plans with drug coverage
6. Thurston County 70,541 with Medicare · 53% in Medicare Advantage · 24 Advantage plans with drug coverage
7. Kitsap County 67,198 with Medicare · 40% in Medicare Advantage · 20 Advantage plans with drug coverage
8. Whatcom County 54,297 with Medicare · 47% in Medicare Advantage · 4 Advantage plans with drug coverage
9. Yakima County 46,979 with Medicare · 47% in Medicare Advantage · 3 Advantage plans with drug coverage
10. Benton County 41,839 with Medicare · 32% in Medicare Advantage · 6 Advantage plans with drug coverage

All 39 counties, A to Z

• Adams County2,979 with Medicare · 35% in Medicare Advantage · 3 Advantage plans with drug coverage
• Asotin County6,947 with Medicare · 27% in Medicare Advantage · 2 Advantage plans with drug coverage
• Benton County41,839 with Medicare · 32% in Medicare Advantage · 6 Advantage plans with drug coverage
• Chelan County20,308 with Medicare · 41% in Medicare Advantage · 5 Advantage plans with drug coverage
• Clallam County29,910 with Medicare · 24% in Medicare Advantage · 1 Advantage plans with drug coverage
• Clark County108,542 with Medicare · 67% in Medicare Advantage · 25 Advantage plans with drug coverage
• Columbia County1,356 with Medicare · 23% in Medicare Advantage · 3 Advantage plans with drug coverage
• Cowlitz County29,288 with Medicare · 68% in Medicare Advantage · 16 Advantage plans with drug coverage
• Douglas County9,556 with Medicare · 41% in Medicare Advantage · 4 Advantage plans with drug coverage
• Ferry County2,514 with Medicare · 27% in Medicare Advantage · 3 Advantage plans with drug coverage
• Franklin County12,804 with Medicare · 37% in Medicare Advantage · 5 Advantage plans with drug coverage
• Garfield County746 with Medicare · 13% in Medicare Advantage · 3 Advantage plans with drug coverage
• Grant County18,302 with Medicare · 37% in Medicare Advantage · 5 Advantage plans with drug coverage
• Grays Harbor County22,691 with Medicare · 26% in Medicare Advantage · 3 Advantage plans with drug coverage
• Island County27,342 with Medicare · 42% in Medicare Advantage · 7 Advantage plans with drug coverage
• Jefferson County15,190 with Medicare · 18% in Medicare Advantage · 9 Advantage plans with drug coverage
• King County368,813 with Medicare · 54% in Medicare Advantage · 22 Advantage plans with drug coverage
• Kitsap County67,198 with Medicare · 40% in Medicare Advantage · 20 Advantage plans with drug coverage
• Kittitas County10,860 with Medicare · 28% in Medicare Advantage · 3 Advantage plans with drug coverage
• Klickitat County7,175 with Medicare · 12% in Medicare Advantage · 2 Advantage plans with drug coverage
• Lewis County23,261 with Medicare · 57% in Medicare Advantage · 13 Advantage plans with drug coverage
• Lincoln County3,779 with Medicare · 20% in Medicare Advantage · 3 Advantage plans with drug coverage
• Mason County20,064 with Medicare · 46% in Medicare Advantage · 10 Advantage plans with drug coverage
• Okanogan County12,244 with Medicare · 30% in Medicare Advantage · 5 Advantage plans with drug coverage
• Pacific County9,308 with Medicare · 22% in Medicare Advantage · 2 Advantage plans with drug coverage
• Pend Oreille County4,686 with Medicare · 31% in Medicare Advantage · 3 Advantage plans with drug coverage
• Pierce County176,141 with Medicare · 52% in Medicare Advantage · 27 Advantage plans with drug coverage
• San Juan County6,784 with Medicare · 18% in Medicare Advantage · 2 Advantage plans with drug coverage
• Skagit County36,053 with Medicare · 45% in Medicare Advantage · 10 Advantage plans with drug coverage
• Skamania County3,036 with Medicare · 26% in Medicare Advantage · 8 Advantage plans with drug coverage
• Snohomish County152,940 with Medicare · 60% in Medicare Advantage · 23 Advantage plans with drug coverage
• Spokane County123,249 with Medicare · 57% in Medicare Advantage · 18 Advantage plans with drug coverage
• Stevens County14,719 with Medicare · 36% in Medicare Advantage · 3 Advantage plans with drug coverage
• Thurston County70,541 with Medicare · 53% in Medicare Advantage · 24 Advantage plans with drug coverage
• Wahkiakum County1,761 with Medicare · 46% in Medicare Advantage · 11 Advantage plans with drug coverage
• Walla Walla County15,018 with Medicare · 33% in Medicare Advantage · 6 Advantage plans with drug coverage
• Whatcom County54,297 with Medicare · 47% in Medicare Advantage · 4 Advantage plans with drug coverage
• Whitman County7,083 with Medicare · 29% in Medicare Advantage · 2 Advantage plans with drug coverage
• Yakima County46,979 with Medicare · 47% in Medicare Advantage · 3 Advantage plans with drug coverage

Sources: CMS Medicare Monthly Enrollment, July 2026, and the CMS 2027 plan landscape. Medicare Advantage here includes other Medicare health plans, such as cost plans and PACE. Before you meet any agent, check their Washington license.

Keep reading

• How to find a good Medicare agent near youWhere to look for a local Medicare agent, how to narrow the list to one or two, and the five-minute checks to do before you share anything.
• Medicare Open Enrollment checklist: what to check before December 7A step-by-step checklist for the October 15 to December 7, 2026 Open Enrollment Period: what to read in your plan's letter, what's changing for 2027, what you can switch, and what happens if you do nothing.
• Moving to another state with Medicare: what changes and what to doOriginal Medicare moves with you; most Medicare Advantage and drug plans don't. What happens to each kind of coverage when you move, your window to switch, and why your agent must be licensed in your new state.