King County continued to experience net outmigration of income between tax years 2022 and 2023, according to Internal Revenue Service data. About 68,606 tax filers moved out while 67,282 moved in, resulting in a net loss of roughly $2.19 billion in adjusted gross income.
Most residents relocating stayed within the region. About 17 percent moved to Snohomish County and 15 percent to Pierce County, often citing lower housing costs. Median home prices in King County reached about $859,000, compared with $750,000 in Snohomish County and $580,000 in Pierce County.
Across Washington, the state recorded a net loss of 8,291 tax filers and about $547.8 million in adjusted gross income during the same period.
Economists note that employment shifts after pandemic expansion and rising housing costs have influenced mobility patterns. The state’s new 9.9 percent tax on income above $1 million, scheduled to take effect in 2028, has also raised questions about future migration trends.
