ZIP code 98031

ZIP 98031 is a small city in King County, Washington, with 40,898 residents counted in the Census American Community Survey 2019-2023 ACS 5-year estimates, which places it #42 of 605 ranked by population — larger than 93% of them. The median age here is 36.8 years against 39.1 nationally, a slightly younger profile than the country as a whole. Places under 65,000 residents only appear in the five-year release, never the one-year file, so these values pool sixty months of responses and lag the current year by design.

Households in ZIP 98031 earn a median of $101,458 a year, 29.2% above the national figure of $78,538. The median is the midpoint household, not an average, so a handful of very high earners cannot drag it upward the way they distort a mean. Poverty reaches 10.6% of residents here, below the 12.4% national rate.

The typical owner-occupied home in ZIP 98031 is valued at $552,300, 82% above the national figure, while median gross rent runs $1,956 a month, 39.1% above the national figure, or roughly $23,472 across a full year. A household on the local median income would put about 23.1% of gross pay toward that rent against the federal 30% cost-burden threshold, so renting here is within the standard affordability guideline. The home-price-to-income ratio works out to 5.4×, against roughly 3.9× nationally, so buying is harder here than in the average US market. 67.1% of occupied homes are owner-occupied versus 65% nationally, so the market leans toward owners. Rent is reported gross — contract rent plus tenant-paid utilities — which is why it runs above the advertised price on a listing for the same unit.

Every value on this page is published directly by the Census for this area — nothing is modelled or interpolated. Small-area estimates still carry wider margins of error than state or national figures, so check the linked ACS tables before relying on them for lending, appraisal or legal work.

ZIP 98031 is tabulated inside King County, Washington, one of 86 ZIP areas the Census publishes for that county and 605 across Washington. This is a dense urban ZIP, where a single postal boundary can hold more residents than an entire rural county. County assignment on this page follows the largest share of the ZIP's land area, which matters where a delivery route crosses a county line: mail addressed to 98031 can be handled by a post office in a neighbouring county even though the tabulation area is filed here.

Against its own county, 98031 reports a median household income of $101,458, 20% below the $127,093 county median, and 25% above the $80,861 typical WA ZIP. Owner-occupied homes are valued at a median of $552,300, 31% below the county figure and 31% above the statewide ZIP median. Rent is reported gross — the contract amount plus tenant-paid utilities — at $1,956 a month, which is why it reads higher than the advertised rent on a listing for the same unit.

Washington charges 6.5% statewide, and local governments overlapping 98031 may add county, city or special-district levies on top. We publish the state floor for this ZIP rather than guessing a combined figure, because ZIP boundaries and taxing-district boundaries were drawn for different purposes and do not line up.

Everything above comes from the Census Bureau American Community Survey 2019-2023 ACS 5-year estimates for this ZIP Code Tabulation Area, with sales tax rates traced to the state revenue agency. Five-year estimates pool sixty months of responses, so they are stable enough to compare 98031 with its neighbours but always trail the current year, and any value the Census suppressed for sample size is shown as unpublished rather than filled in with a model.