Property Taxes in Seatac, Washington
Median Seatac, Washington effective property tax rate: 1.09%, significantly higher than the national median of 1.02%, and higher than the Washington state median of 0.92%.
Median Seatac, Washington home value: $527,000
Median annual Seatac, Washington tax bill: $5,652, $3,252 higher than the national median property tax bill of $2,400.
How are property taxes in King calculated?
Property taxes in Seatac, Washington are calculated based on the tax assessed value, which is often lower than the actual market value due to property tax exemptions such as the homestead or senior exemption.
Understanding Seatac's property tax system, exemptions, and reduction opportunities can lead to significant savings. Regardless of where you live in Seatac, knowing local tax details benefits homeowners and investors.
Last Updated April 13, 2026
How Does the Seatac Property Tax Calculator Work?
Use this Seatac property tax calculator to estimate your annual tax bill. Enter your property's assessed value and our calculator applies Seatac's median effective tax rate of 1.09% — based on actual property records in King County — to generate your estimate.
Enter your property's estimated assessed value — the figure used to calculate your bill, which reflects any exemptions you hold and is typically lower than your home's market value. Our calculator applies Seatac's median effective rate across all local levies, providing a more accurate estimate than applying a single county millage rate.
Your bill may vary by ZIP code within Seatac: rates range from $5,065 in 98198 to $5,942 in 98188, primarily due to differences in school district levies and local assessment districts. Seatac's median property tax bill of $5,652 is higher than the national median property tax bill of $2,400 and higher than Washington's median property tax bill by $3,252.
If your estimate is higher than expected, Ownwell can appeal your Seatac assessment — you only pay if we save you money.
About Seatac Property Taxes
About Property Taxes in Seatac, King, Washington
Seatac’s median effective property tax rate of 1.09% is lower than the Washington state median of 0.92% and higher than the national median of 1.02%. This rate reflects the King County base levy combined with local school district levies and Local improvement districts (LIDs) that vary by subdivision throughout the city.
Property tax rates are not uniform across Seatac. Homeowners in the 98148 ZIP code carry a median effective rate of 1.10%, while those in 98198 pay 1.09%. This spread reflects how school district boundaries and local assessment districts are drawn across King County. Understanding which part of Seatac you live in can make a meaningful difference to your annual tax bill.
Seatac homeowners who believe their assessed value is too high can file a formal appeal with the local Tax Assessor after the July notice date each year.
If your estimated bill seems higher than expected, Ownwell can review your assessment and protest on your behalf. You only pay if we save you money.
Property Tax Rates Across Seatac, King County, Washington
As noted earlier, local government entities set tax rates, which can vary widely within a state.
Why? Because annually, each county estimates its required budget to provide services and divides that by the total value of all taxable property within its jurisdiction. This calculation results in the property tax rate.
While there are votes and laws involved in setting tax rates and budgets, in a nutshell, this is the annual process.
Below, you can compare Seatac's effective property tax rate to other cities in Washington and the median property tax rates in Washington and the U.S.
Our median effective property tax rate (tax bill ÷ assessor's market value) accounts for exemptions and deductions, making it more accurate than the general median tax rate, which is the midpoint of statutory rates before adjustments.
Median Effective Seatac Tax Rate
1.09%
Our median effective property tax rate (tax bill ÷ assessor's market value) accounts for exemptions and deductions, making it more accurate than the general median tax rate, which is the midpoint of statutory rates before adjustments.
Median Effective King County Tax Rate
0.99%
Median Effective Washington Tax Rate
0.92%
Median Effective United States Tax Rate
1.27%
Property Tax Rates Across Seatac, King County, Washington
| Zip | 10th Percentile | 25th Percentile | Median Tax Rate | 75th Percentile | 90th Percentile |
|---|---|---|---|---|---|
| 98148 | 1.09% | 1.09% | 1.10% | 1.11% | 1.15% |
| 98168 | 1.08% | 1.08% | 1.09% | 1.09% | 1.10% |
| 98188 | 1.07% | 1.08% | 1.09% | 1.10% | 1.12% |
| 98198 | 1.00% | 1.01% | 1.09% | 1.09% | 1.10% |
Source: Ownwell
Save on Your Property Taxes and More With Ownwell
$774
Average Annual Tax Savings
Property Tax Assessment Values Across Seatac, King County, Washington
When examining property taxes in Seatac, Washington, understanding the distinction between "market value" and "assessed value" is crucial.
The market value is what a willing buyer would pay to a willing seller in an open and competitive market, often influenced by location, property condition, and economic market trends. The King County assessor estimates the market value for tax purposes.
The assessed value is the market value minus any applicable exemptions or limits determined by local laws and offerings. The tax assessed value is the figure used to calculate your property taxes or the amount multiplied by your tax rate to get your tax bill.
Assessment notices:
In King County, assessment notices are sent in the spring each year. They'll typically reach your mailbox by the middle of July.
Each property owner receives an assessment notice that contains both the market value and assessed value, along with an estimate of your property tax bill. By providing insights into how assessed and market values are determined, this section helps property owners navigate their tax responsibilities and understand the valuation processes affecting their property taxes in Seatac.
For example, the median home price in Seatac is $527,000, with tax bills ranging significantly across the county. 98188 has the highest median home price at $551,000.
Property Tax Assessment Values Across Seatac, King County, Washington
Source: Ownwell
$275,000
$3,858,750
$7,442,500
Median Seatac Market Value
$527,000
Median King County Market Value
$774,000
Median Washington Market Value
$501,600
Median United States Market Value
$274,101
Property Tax Assessment Values Across Seatac, King County, Washington
| Zip | 10th Percentile | 25th Percentile | Median Home Price | 75th Percentile | 90th Percentile |
|---|---|---|---|---|---|
| 98148 | $324,400 | $438,000 | $489,000 | $558,000 | $672,000 |
| 98168 | $370,800 | $454,000 | $512,000 | $590,000 | $687,200 |
| 98188 | $322,000 | $470,000 | $551,000 | $638,000 | $823,000 |
| 98198 | $372,200 | $404,000 | $473,000 | $551,000 | $620,000 |
Source: Ownwell
Save on Your Property Taxes and More With Ownwell
$774
Average Annual Tax Savings
Property Tax Bills Across Seatac, King County, Washington
Property tax bills in Seatac are based on the assessed value of a home and the local tax rate set for King County. When a home’s market value rises, the assessed value can rise too, which can increase the property tax bill. For homeowners in Seatac, that means taxes can change even if nothing about the home itself has changed.
The median home price in Seatac is $527,000, and property tax bills are often well above the national median property tax bill of $2,400. The 25th percentile tax bill is $4,684, while the 75th percentile is $6,609. At the high end, the 90th percentile reaches $8,017. Median tax bills also vary by ZIP code, from $5,065 in 98198 to $5,942 in 98188.
Ownwell can help homeowners review their assessed value and appeal unfair property taxes, which may lower their bill and help them keep more of their money.
Median Seatac Tax Bill
$5,652
Median King County Tax Bill
$7,644
Median Washington Tax Bill
$4,512
Median United States Tax Bill
$3,209
Property Tax Bills Across Seatac, King County, Washington
| Zip | 10th Percentile | 25th Percentile | Median Tax Bill | 75th Percentile | 90th Percentile |
|---|---|---|---|---|---|
| 98148 | $3,286 | $4,663 | $5,340 | $6,070 | $7,757 |
| 98168 | $3,155 | $4,843 | $5,541 | $6,323 | $7,416 |
| 98188 | $2,653 | $4,896 | $5,942 | $6,905 | $8,798 |
| 98198 | $3,215 | $3,890 | $5,065 | $5,794 | $6,655 |
Source: Ownwell
Save on Your Property Taxes and More With Ownwell
$774
Average Annual Tax Savings
Don't miss the deadline to appeal!
Dates | |
|---|---|
| Appeal Deadline | July 1 |
| Tax Bill | |
| Issued | February 10 |
| Due Date #1 | April 30 |
| Due Date #2 | October 31 |
Links | |
|---|---|
| King Tax Assessor | |
| Phone | (206) 296-7300 |
| Website | blue.kingcounty.com |
| assessor.info@kingcounty.gov | |