Wash. Admin. Code § 284-43-6701
(1) The following geographic rating areas are designated for Washington state for nongrandfathered individual and small group plans issued or renewed on or after January 1, 2019:
Area 1: King County.
Area 2/West: Clallam, Cowlitz, Grays Harbor, Jefferson, Kitsap, Lewis, Pacific, and Wahkiakum counties.
Area 3/South: Clark, Klickitat, and Skamania counties.
Area 4/Northeast: Ferry, Lincoln, Pend Oreille, Spokane, and Stevens counties.
Area 5/South Sound: Mason, Pierce, and Thurston counties.
Area 6/South Central: Benton, Franklin, Kittitas, and Yakima counties.
Area 7/North Central: Adams, Chelan, Douglas, Grant, and Okanogan counties.
Area 8/Northwest: Island, San Juan, Skagit, Snohomish, and Whatcom counties.
Area 9/Southeast: Asotin, Columbia, Garfield, Walla Walla, and Whitman counties.
[Statutory Authority: RCW 48.02.060, 48.43.733, and 45 C.F.R. 147.102. WSR 18-07-053, § 284-43-6701, filed 3/14/18, effective 4/14/18.]