Migration to and from King County, Washington
Where King County residents came from and where they went over the 5-year window 2016-2020. Census ACS County-to-County Migration Flows, 2020 5-yr (frozen vintage).
Total inflow
170,428
people moved in (5-yr)
Total outflow
135,528
people moved out (5-yr)
Net migration
+34,900
inflow minus outflow
Top 10 counties people moved IN from
| Origin | State / Region | People (5-yr) |
|---|---|---|
| Asia | 18,318 | |
| Snohomish County | Washington | 11,035 |
| Pierce County | Washington | 10,614 |
| Europe | 5,389 | |
| Los Angeles County | California | 5,175 |
| Santa Clara County | California | 3,095 |
| Maricopa County | Arizona | 2,717 |
| Central America | 2,716 | |
| Cook County | Illinois | 2,485 |
| Clark County | Washington | 2,189 |
Top 10 counties people moved OUT to
| Destination | State / Region | People (5-yr) |
|---|---|---|
| Snohomish County | Washington | 21,771 |
| Pierce County | Washington | 21,425 |
| Kitsap County | Washington | 3,349 |
| Maricopa County | Arizona | 3,295 |
| Spokane County | Washington | 3,045 |
| Los Angeles County | California | 2,933 |
| Whatcom County | Washington | 2,286 |
| Thurston County | Washington | 2,209 |
| Kittitas County | Washington | 2,116 |
| Santa Clara County | California | 1,802 |
Explore King County
- Business data for King CountyConstruction sector establishments, employment, payroll
- Cities in WashingtonACS demographic profiles for places statewide
- ZIP code lookupSearch demographic data by ZIP code
- Opportunity IndexRank counties by business growth potential
- Federal contracts in WAGovBids: RFPs, awards, NAICS matching
- New business filings in WashingtonNewFilings: fresh SOS registrations
Methodology
- Counts represent the number of people aged 1+ who reported a different residence at the survey reference date than they did one year earlier, aggregated across the 5-year sample window 2016-2020.
- Outbound (OUT) flows are reported less frequently than inbound (IN) because the survey captures the destination side of each move. Many county pairs have null OUT counts, which is normal.
- "Total inflow" sums the published MOVEDIN counts across all origin counties, including foreign-region inflows (Africa, Asia, Central America, etc.). It is not the same as net population change.
- Frozen vintage. The Census Bureau has not released a newer county-to-county migration flows file. The 2020 5-yr vintage (covering 2016-2020) is the latest available as of build date.
Source: U.S. Census Bureau, American Community Survey, County-to-County Migration Flows: 2016-2020. Vintage: 2020 5-yr. Generated: 2026-05-28. FIPS: 53033.