Mercer Island, San Juan County, Washington Property Taxes
Median Mercer Island, WA effective property tax rate: 0.13%, significantly lower than the national median of 1.02%, but lower than the WA state median of 0.88%.
Median Mercer Island, WA home value: $390,160
Median annual Mercer Island, WA tax bill: $526, $1,874 lower than the national median property tax bill of $2,400.
How are property taxes in San Juan calculated?
Property taxes in Mercer Island, WA 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 Mercer Island’s property tax system, exemptions, and reduction opportunities can lead to significant savings. Regardless of where you live in Mercer Island, knowing local tax details benefits homeowners and investors.
Last Updated March 1, 2025
Mercer Island, San Juan County, Washington Property Tax Bill Calculator
$100,000
$1,500,000
$3,000,000
Median Effective Tax Rate
0.13%
Estimate Property Tax Bill
$507
$471
$1,102
Average Tax Savings
Property Tax Rates Across Mercer Island, San Juan County, Washington
Local government entities set tax rates, which can vary significantly within a state. This is because each county annually estimates its required budget to provide services and divides that by the total value of all taxable property within its jurisdiction, resulting in the property tax rate. While votes and laws influence tax rates and budgets, this is the core of the annual process.
In Mercer Island, located in King County, Washington, property owners experience a unique tax landscape. The effective property tax rate in Mercer Island is 0.86%, which is significantly lower than the national median of 1.02%. This means residents typically pay less in property taxes compared to the national average. The median property tax bill in Mercer Island stands at $8,007, which is considerably higher than the national median of $2,400. This discrepancy is largely due to the higher property values in the area.
When comparing Mercer Island’s effective property tax rate to other cities in Washington and the median property tax rates in Washington and the U.S., it becomes evident how local economic factors and property values influence tax obligations.
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 Mercer Island Tax Rate
0.13%
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 San Juan County Tax Rate
0.62%
Median Effective Washington Tax Rate
0.88%
Median Effective United States Tax Rate
1.02%
Property Tax Rates Across Mercer Island, San Juan County, Washington
Zip | 10th Percentile | 25th Percentile | Median Tax Rate | 75th Percentile | 90th Percentile |
---|---|---|---|---|---|
98040 | N/A | N/A | N/A | N/A | N/A |
Source: Ownwell
$1,102
Average Mercer Island Tax Savings
Save on your property taxes & more with Ownwell
Property Tax Assessment Values Across Mercer Island, San Juan County, Washington
When examining property taxes in Mercer Island, WA, 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's Office 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 March. 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 Mercer Island.
For example, the median home price in Mercer Island is $390,160, with tax bills ranging significantly across the county. 98040 has the highest median home price at $1,700,000.
Property Tax Assessment Values Across Mercer Island, San Juan County, Washington
Source: Ownwell

$496,770
$807,395
$1,118,020
Median Mercer Island Market Value
$390,160
Median San Juan County Market Value
$691,520
Median Washington Market Value
$482,000
Median United States Market Value
$235,294
Property Tax Assessment Values Across Mercer Island, San Juan County, Washington
Zip | 10th Percentile | 25th Percentile | Median Home Price | 75th Percentile | 90th Percentile |
---|---|---|---|---|---|
98040 | N/A | N/A | N/A | N/A | N/A |
Source: Ownwell
$1,102
Average Mercer Island Tax Savings
Save on your property taxes & more with Ownwell
Property Tax Bills Across Mercer Island, San Juan County, Washington
In Mercer Island, located in King County, Washington, property tax bills are determined using the assessed value of a property. The local tax rate is then applied to this assessed value to calculate the annual tax bill. Factors such as the property's location, size, and any improvements can influence its assessed value. Homeowners in Mercer Island face a median property tax bill of $526, which is significantly lower than the national median of $2,400. This lower tax burden can be attributed to Washington's relatively low property tax rates compared to many other states.
Homeowners may feel the impact of these taxes on their finances, especially if property values rise, leading to higher assessments. Ownwell helps homeowners by offering property tax appeal and exemption services. By analyzing property assessments and identifying discrepancies, Ownwell can assist in reducing tax liabilities. This ensures that homeowners pay only their fair share, potentially saving them money and providing peace of mind.
Property Tax Bills Across Mercer Island, San Juan County, Washington
Source: Ownwell

$2,218
$4,400
$6,581
Median Mercer Island Tax Bill
$526
Median San Juan County Tax Bill
$4,068
Median Washington Tax Bill
$4,284
Median United States Tax Bill
$2,400
Property Tax Bills Across Mercer Island, San Juan County, Washington
Zip | 10th Percentile | 25th Percentile | Median Tax Bill | 75th Percentile | 90th Percentile |
---|---|---|---|---|---|
98040 | N/A | N/A | N/A | N/A | N/A |
Source: Ownwell
$1,102
Average Mercer Island Tax Savings
Save on your property taxes & more with Ownwell
Don't miss the deadline to appeal!
Dates | |
---|---|
Appeal Deadline | December 1 |
Tax Bill | |
Issued | February 10 |
Due Date #1 | April 30 |
Due Date #2 | October 31 |
Links | |
---|---|
San Juan Tax Assessor | |
Website | parcel.sanjuanco.com |
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