King County homeowners were surprised by property tax bills that increased dramatically this year, alongside increased assessed home values. This has confused many homeowners, particularly those who may have seen their home price estimates drop on popular websites like Zillow.
Washington Property Tax Estimates
According to King County Chief Appraiser Jim Hall, the mismatch is the result of a lag between home value assessments and property tax bills, which is intended to give the King County assessor’s office enough time to estimate the value of homes in the area.
Washington state law requires that taxable home values are based on estimates from the first day of the year before taxes are due. For example, taxes due in 2026 are based on what homes were worth on January 1, 2025.
Property owners received home valuations used for the 2026 tax year last summer. Many who disagreed with the higher valuations at the time filed for appeals. The assessor’s office saw a 17% increase compared to the typical number of annual appeals, Hall said.
It is now too late to appeal those home valuations.
Assessing the Market
This year, assessed home values reflect the strength of the housing market at the end of 2024, rather than any weaknesses in 2025. In 2024, high mortgage rates kept inventory down and prices high, Windermere principal economist Jeff Tucker said.
Except for Burien, Hunts Point, Beaux Arts and Normandy Park, where median home values slightly dipped, median home values rose across King County cities between January 1, 2024, and January 1, 2025.
Some cities, including Seattle and Federal Way, saw median single-family home values rise just below 4%, while others, including Kirkland and Bothell, saw values jump more than 14%. Skykomish home values skyrocketed more than 30%.
This led to a property taxes increases across all cities between tax years, ranging from 1% more taxes due on the median home value in Beaux Arts to a whopping 39% more taxes due on the median home value in Skykomish.
Moving Forward
Property taxes could decrease slightly next year, reflecting the 2025 housing market. Taxes also depend on other factors, including local levies.
To learn more about property taxes in King County, read this article in The Seattle Times.