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Washington Medicare statistics by county
By Vadim Marusin, licensed Medicare insurance agent in Washington (WAOIC #1365574). Insurer data checked against the state chart current as of October 8, 2026.
How many people have Medicare in each Washington county, how many are in Original Medicare, and how the state is changing. Updated from CMS enrollment data; figures for July 2026.
- People on Medicare in WA
- 1,586,306
- In Original Medicare
- 797,700 (50%)
- Qualify by disability
- 127,500
- Growth since 2013
- 44%
- Washington
Source: CMS, Medicare Monthly Enrollment, county level (July 2026).
- 1.10M2013
- ’14
- ’15
- ’16
- ’17
- ’18
- ’19
- ’20
- ’21
- ’22
- ’23
- ’24
- 1.56M2025
Source: CMS, Medicare Monthly Enrollment, county level (July 2026).
County maps
- Original Medicare share
- < 48%
- 48% to 59%
- 59% to 69%
- 69% to 76%
- 76%+
Source: CMS, Medicare Monthly Enrollment, county level (July 2026).
- Age 85 or older
- < 9.0%
- 9.0% to 10.5%
- 10.5% to 10.8%
- 10.8% to 11.6%
- 11.6%+
Source: CMS, Medicare Monthly Enrollment, county level (July 2026).
- King368,813
- Pierce176,141
- Snohomish152,940
- Spokane123,249
- Clark108,542
- Thurston70,541
- Kitsap67,198
- Whatcom54,297
- Yakima46,979
- Benton41,839
- Skagit36,053
- Clallam29,910
July 2026. Source: CMS, Medicare Monthly Enrollment, county level (July 2026).
- 382,89665-69
- 397,96370-74
- 316,53175-79
- 199,46280-84
- 102,44685-89
- 59,50890+
July 2026. Source: CMS, Medicare Monthly Enrollment, county level (July 2026).
All 39 counties
| County | On Medicare | Original Medicare | Original share | Disability | 85+ (of 65+) | Growth since 2013 | Medigap insurers |
|---|---|---|---|---|---|---|---|
| Adams County | 2,979 | 1,939 | 65.1% | 10.8% | 9.5% | 33% | 15 |
| Asotin County | 6,947 | 5,072 | 73.0% | 12.0% | 13.4% | 27% | 15 |
| Benton County | 41,839 | 28,322 | 67.7% | 9.4% | 11.1% | 51% | 15 |
| Chelan County | 20,308 | 12,064 | 59.4% | 6.8% | 11.8% | 41% | 15 |
| Clallam County | 29,910 | 22,783 | 76.2% | 6.3% | 11.0% | 38% | 15 |
| Clark County | 108,542 | 35,664 | 32.9% | 7.9% | 10.8% | 59% | 14 |
| Columbia County | 1,356 | 1,044 | 77.0% | 9.3% | 12.6% | 19% | 15 |
| Cowlitz County | 29,288 | 9,490 | 32.4% | 11.6% | 10.7% | 32% | 15 |
| Douglas County | 9,556 | 5,662 | 59.3% | 6.8% | 12.6% | 45% | 15 |
| Ferry County | 2,514 | 1,830 | 72.8% | 9.1% | 8.6% | 38% | 15 |
| Franklin County | 12,804 | 8,045 | 62.8% | 10.3% | 9.7% | 59% | 15 |
| Garfield County | 746 | 646 | 86.6% | 8.3% | 6.4% | 23% | 15 |
| Grant County | 18,302 | 11,470 | 62.7% | 10.7% | 10.7% | 35% | 15 |
| Grays Harbor County | 22,691 | 16,856 | 74.3% | 12.0% | 8.9% | 42% | 15 |
| Island County | 27,342 | 15,990 | 58.5% | 5.0% | 10.6% | 50% | 15 |
| Jefferson County | 15,190 | 12,490 | 82.2% | 3.9% | 10.5% | 51% | 15 |
| King County | 368,813 | 171,219 | 46.4% | 5.9% | 12.3% | 37% | 15 |
| Kitsap County | 67,198 | 40,182 | 59.8% | 7.0% | 10.2% | 52% | 15 |
| Kittitas County | 10,860 | 7,807 | 71.9% | 7.1% | 11.1% | 62% | 15 |
| Klickitat County | 7,175 | 6,319 | 88.1% | 7.7% | 9.0% | 44% | 15 |
| Lewis County | 23,261 | 10,073 | 43.3% | 11.1% | 10.5% | 34% | 15 |
| Lincoln County | 3,779 | 3,035 | 80.3% | 9.1% | 10.6% | 46% | 15 |
| Mason County | 20,064 | 10,933 | 54.5% | 8.4% | 9.6% | 40% | 15 |
| Okanogan County | 12,244 | 8,614 | 70.4% | 8.4% | 9.8% | 31% | 15 |
| Pacific County | 9,308 | 7,224 | 77.6% | 8.8% | 8.6% | 41% | 15 |
| Pend Oreille County | 4,686 | 3,251 | 69.4% | 10.7% | 8.2% | 49% | 15 |
| Pierce County | 176,141 | 84,743 | 48.1% | 9.4% | 10.8% | 44% | 15 |
| San Juan County | 6,784 | 5,564 | 82.0% | 2.5% | 10.8% | 52% | 15 |
| Skagit County | 36,053 | 19,751 | 54.8% | 6.7% | 11.5% | 47% | 15 |
| Skamania County | 3,036 | 2,252 | 74.2% | 7.6% | 8.8% | 52% | 15 |
| Snohomish County | 152,940 | 61,852 | 40.4% | 7.2% | 10.6% | 52% | 15 |
| Spokane County | 123,249 | 52,829 | 42.9% | 11.2% | 10.9% | 46% | 15 |
| Stevens County | 14,719 | 9,403 | 63.9% | 9.5% | 9.2% | 43% | 15 |
| Thurston County | 70,541 | 33,252 | 47.1% | 9.2% | 10.5% | 55% | 15 |
| Wahkiakum County | 1,761 | 948 | 53.8% | 8.9% | 6.6% | 44% | 15 |
| Walla Walla County | 15,018 | 10,022 | 66.7% | 8.1% | 13.3% | 35% | 15 |
| Whatcom County | 54,297 | 28,876 | 53.2% | 7.1% | 11.0% | 50% | 15 |
| Whitman County | 7,083 | 5,051 | 71.3% | 10.0% | 11.7% | 38% | 15 |
| Yakima County | 46,979 | 25,130 | 53.5% | 11.2% | 11.6% | 27% | 15 |
About these numbers
CMS counts every person entitled to Medicare by county of residence each month. "Original Medicare" here means people not enrolled in a Medicare Advantage or other Medicare health plan; they are the people who can buy a Medicare Supplement policy. CMS does not publish how many of them actually own one. Yearly figures are CMS's annual averages.
Common questions
How many people in Washington have Medicare?
1,586,306 in July 2026, according to CMS Medicare Monthly Enrollment data.
How many Washington residents are in Original Medicare?
797,700 (50.3%). The rest, 788,606, were in Medicare Advantage or other Medicare health plans.
Which Washington county has the highest share in Original Medicare?
Klickitat County, at 88.1%.
How many Washington Medicare beneficiaries have Medigap?
CMS doesn't publish Medigap enrollment by county. Original Medicare enrollment is the closest public measure of who can buy a Medigap policy.