King County has no single property tax rate. Your rate depends on which taxing districts overlap your parcel, and the combinations across the county produce hundreds of distinct tax code areas, each with its own composite rate. Total levy rates generally fall between $8 and $13 per $1,000 of assessed value, and the projected median property tax bill for a King County homeowner in 2026 is roughly $4,465.1King County. Trends in King County Property Values and Taxes
Why the Rate Depends on Where You Live
Your bill is the sum of levies from every taxing district covering your parcel: the state, King County, your city or town, your school district, and often a fire district, library district, port authority, and sometimes hospital or flood-control districts. Each district sets its own levy. The county assessor divides each district’s total levy by the total assessed value within that district, and the result is expressed as a dollar amount per $1,000 of assessed value.
The state school levy, authorized under RCW 84.52.065, is one of the largest single components on most bills and funds basic education statewide at a uniform rate.2Washington State Legislature. Washington Code RCW 84.52.065 – State Levy for Common Schools Local school districts layer voter-approved amounts on top for operations and construction. Fire, library, and port levies add more.
Because the mix of districts varies by location, an identical home in Seattle, Bellevue, Renton, and unincorporated King County can carry noticeably different total rates. The King County Assessor publishes annual levy rate reports that break down every district’s contribution to the total rate at your address.3King County. Levy Rate Reports That is the only way to see your exact rate.
How to Calculate Your Bill
Divide your home’s assessed value by 1,000, then multiply by your total levy rate. A home assessed at $750,000 in a tax code area with a combined rate of $9.50 per $1,000 would owe $7,125 for the year. The same home in an area with an $11.00 rate would owe $8,250.
Two things move that number each year. Your assessed value shifts with market conditions, and your combined levy rate shifts as districts adjust their levies and voters approve or reject ballot measures. Countywide, King County collected roughly $7.7 billion in property taxes for the 2025 tax year.4King County. 2025 Property Taxes
Why Rising Home Values Don’t Mean Proportionally Higher Taxes
Washington caps how fast regular, non-voter-approved property tax levies can grow. Under RCW 84.55.010, most taxing districts cannot increase their total regular levy by more than 1% per year, plus an adjustment for new construction and improvements within the district.5Washington State Legislature. Washington Code Chapter 84.55 – Limitations Upon Regular Property Taxes Even when values jump, the total dollars a district collects through regular levies stay capped at 1% above the prior year’s highest levy.
The result is counterintuitive. If values rise sharply across the county, the per-$1,000 rate actually drops, because the district’s capped revenue is spread over a larger assessed value base. Your bill may still rise, but not in step with the value increase. Voter-approved levies and bonds sit outside the 1% cap, which is why school, parks, or emergency services measures can push your total rate higher than the cap alone would suggest.
How Your Assessed Value Gets Set
Washington law requires property to be valued at 100% of true and fair market value, meaning the price a willing buyer would pay a willing seller with neither under pressure to close.6FindLaw. Washington Code 84.40.030 – Property Taxes The King County Assessor updates every parcel annually, using January 1 as the reference date.7Washington State Legislature. Washington Code RCW 84.40.020 – Assessors Duties The office analyzes recent comparable sales within neighborhoods to assign updated values.
Pulling a building permit effectively flags your property for reassessment. Adding square footage, converting a garage into living space, or building an accessory dwelling unit will raise your assessed value when permit records reach the assessor. Cosmetic updates like paint, carpet, or new appliances generally won’t. If you’re planning a major renovation, expect the assessment to rise with it.
Ways to Lower What You Owe
King County administers several state-authorized programs that reduce or postpone property taxes. Eligibility turns on age, disability status, veteran status, and household income.
Senior and Disabled Person Exemption
Under RCW 84.36.381, you may qualify for a partial or full exemption if you are at least 61 years old or retired from regular employment because of a disability. Surviving spouses who are at least 57 and whose late spouse held the exemption also qualify.8Washington State Legislature. Washington Code RCW 84.36.381 – Exemptions, Residences of Senior Citizens and Persons Retired by Reason of Disability You must own and occupy the home as your primary residence.
For the 2026 tax year, combined household disposable income after qualified expense deductions must be $84,000 or less.9King County. Senior Exemption Portal Income includes Social Security, pensions, and most other revenue sources. The level of relief scales with income, so lower-income applicants receive exemptions from a greater portion of their bill. Apply through the King County Assessor with documentation of age, income, and residency.
Disabled Veteran Exemption
Veterans with a service-connected disability rating from the U.S. Department of Veterans Affairs can qualify for the same program. The eligibility threshold has historically been an 80% combined disability rating, though recent legislation has expanded access.10Washington State Department of Veterans Affairs. Property Tax Relief VA disability compensation and dependency and indemnity compensation are excluded from the disposable income calculation, which can make the income threshold much easier to meet. Military retirement pay does count.
Property Tax Deferral
If you qualify on age or disability grounds but income is lower, Washington’s deferral program offers a different form of relief. The state pays your property taxes and places a lien on the home. You repay the deferred amount, plus 5% annual simple interest, when you sell, move out, or pass away.11Washington State Legislature. Washington Code RCW 84.38.100 – Lien of State, Deferral and Interest For the 2026 program year, combined disposable income cannot exceed $57,000, and the total deferred amount cannot exceed 80% of your equity in the property. The program is a loan against your home equity, not free money.
Appeal Your Valuation
If you believe the assessor overvalued your home, file a petition with the King County Board of Equalization by July 1 or within 60 days of receiving your value notice, whichever is later.12King County. How to Appeal Your Valuation Miss the window and you’re stuck with the assessed value for the year. The strongest appeals use recent comparable neighborhood sales, a professional appraisal, or documented property defects the assessor’s records don’t reflect. Decisions can be appealed further to the Washington State Board of Tax Appeals.
Deadlines and the Cost of Paying Late
King County collects property taxes in two installments. The first half is due by April 30 and the second half by October 31. If your total annual bill is $50 or less, the full amount is due April 30.13Washington State Legislature. Washington Code RCW 84.56.020 – Taxes Collected by Treasurer If a mortgage company collects taxes through escrow, confirm your lender is handling the payment before sending one yourself.
Missing a deadline triggers interest right away. Residential properties with four or fewer units per parcel are charged 9% annual interest on the delinquent amount, calculated monthly. All other property faces 12% annual interest.13Washington State Legislature. Washington Code RCW 84.56.020 – Taxes Collected by Treasurer Residential properties with four or fewer units are exempt from the additional delinquency penalties. Commercial property and larger residential buildings face a 3% penalty on the delinquent amount starting June 1 and an additional 8% penalty starting December 1, stacked on top of the 12% interest.
If any portion of your tax stays unpaid for three full years, King County can initiate tax foreclosure proceedings against the property.14King County. Property Tax Foreclosures Foreclosure applies even when the initial delinquency was a single year.