ZIP Code 98040

ZIP code 98040 is classified by USPS as a standard delivery area and covers roughly 16.5 square miles in Mercer Island, King County, Washington. The area is home to 22,699 residents, producing a population density of 1,373 people per square mile, and falls within the Los Angeles time zone. These USPS and Census boundary values drive every downstream statistic on this page, including the benchmarks that compare 98040 against Washington and the nation.

On the economic side, the median household income for ZIP 98040 sits at $219,069 (141% above the Washington average), while per-capita income is $128,615. The poverty rate stands at 3.8% and the unemployment rate at 3.0%. On housing, the median home value is $2,000,001 (291% above the state average) with median rent at $2,502 per month, and 67.0% of occupied units are owner-occupied, a direct signal of whether 98040 behaves more like a homeowner neighborhood or a renter-heavy ZIP.

Education and household profile round out the picture: 81.4% of adults hold a bachelor's degree or higher, the median age is 46.4, and the average commute is 24 minutes. We also surface 10 nearby ZIP codes within roughly 10 miles and 6 additional ZIPs sharing King County, so you can benchmark 98040 against its immediate geography rather than a national average alone. Every figure is sourced from the U.S. Census Bureau American Community Survey 5-Year Estimates, HUD Fair Market Rents, and FHFA Home Price Index data, no estimates, no proprietary scoring. Verify with HUD →