As of 2015, U.S. cities that are covered by the 206 area code are Seattle, White Center, Des Moines, Shroleine and Bainridge Island, all of which are in the state of Washington. Other cities that fall under the area code are Mercer Island and Burien.
The cities that fall within the area code are also part of either King Country or Kitsap County. The 206 area code was first put into service in the state of Washington in 1947. The number was split three times between 1947 and 2015 into different area numbers, including area codes 509, 360, 235 and 425.