Property Taxes in Diamond, Washington
Median Diamond, Washington effective property tax rate: 1.40%, significantly higher than the national median of 1.02%, and higher than the Washington state median of 0.92%.
Median Diamond, Washington home value: $111,833
Median annual Diamond, Washington tax bill: $1,587, $813 lower than the national median property tax bill of $2,400.
How are property taxes in Whitman calculated?
Property taxes in Diamond, 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 Diamond's property tax system, exemptions, and reduction opportunities can lead to significant savings. Regardless of where you live in Diamond, knowing local tax details benefits homeowners and investors.
Last Updated April 13, 2026
How Does the Diamond Property Tax Calculator Work?
Use this Diamond property tax calculator to estimate your annual property tax bill. Enter your property's assessed value and our calculator applies Diamond's median effective tax rate of 1.40% — based on actual property records in Whitman County — to generate your estimate.
Enter your property's estimated assessed value — the figure the local assessment system uses to calculate your bill, which reflects any exemptions you hold and is typically lower than your home's market value. Our calculator applies Diamond'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 Diamond: rates range from 1.40% in 99111 to 1.40% in 99111, primarily due to differences in school district levies and local assessment districts.
For a more precise estimate, scroll down to explore ZIP code-level tax rate trends across Diamond.
About Diamond Property Taxes
About Property Taxes in Diamond, Whitman, Washington
Diamond’s median effective property tax rate of 1.40% is lower than the Washington state median of 0.92% and higher than the national median of 1.02%. This rate reflects the Whitman 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 Diamond. Homeowners in the 99111 ZIP code carry a median effective rate of 1.40%, while those in the lowest ZIP code also pay 1.40%. This spread — 0.00 percentage points across the same city — reflects how school district boundaries and local assessment districts are drawn across Whitman County. Understanding which part of Diamond you live in can make a meaningful difference to your annual tax bill.
Diamond homeowners who believe their assessed value is too high can file a formal appeal with the local Tax Assessor before the July 1, 2026 deadline each year.
If your estimated bill above 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 Diamond, Whitman 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 Diamond'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 Ă· 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 Diamond Tax Rate
1.40%
Our median effective property tax rate (tax bill Ă· 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 Whitman County Tax Rate
1.40%
Median Effective Washington Tax Rate
0.92%
Median Effective United States Tax Rate
1.27%
Property Tax Rates Across Diamond, Whitman County, Washington
| Zip | 10th Percentile | 25th Percentile | Median Tax Rate | 75th Percentile | 90th Percentile |
|---|---|---|---|---|---|
| 99111 | 0.98% | 1.20% | 1.40% | 1.40% | 1.40% |
Source: Ownwell
Property Tax Assessment Values Across Diamond, Whitman County, Washington
When examining property taxes in Diamond, 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 Whitman 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 Whitman County, assessment notices are sent in the spring each year. They'll typically reach your mailbox by the middle of the month.
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 Diamond.
For example, the median home price in Diamond is $111,833, with tax bills ranging significantly across the county. ZIP code 99111 has the highest median home price at $111,833.
Property Tax Assessment Values Across Diamond, Whitman County, Washington
Source: Ownwell
$9,310
$119,922
$230,534
Median Diamond Market Value
$111,833
Median Whitman County Market Value
$123,566
Median Washington Market Value
$501,600
Median United States Market Value
$274,101
Property Tax Assessment Values Across Diamond, Whitman County, Washington
| Zip | 10th Percentile | 25th Percentile | Median Home Price | 75th Percentile | 90th Percentile |
|---|---|---|---|---|---|
| 99111 | $31,004 | $67,920 | $111,833 | $178,246 | $367,778 |
Source: Ownwell
Property Tax Bills Across Diamond, Whitman County, Washington
Property tax bills in Diamond are calculated by applying local tax rates to a home’s assessed value, which is based on the market value of the property. The assessed value is the starting point for the bill, and local taxing authorities use it to determine how much a homeowner owes each year. Because the bill is tied to value, changes in the housing market can affect what residents pay.
In Diamond, the median home price is $111,833, and the median property tax bill is $1,587. That is below the national median property tax bill of $2,400, which can make local taxes feel more manageable for many homeowners. Still, bills can vary widely from one property to another. In this area, tax bills range from $900 at the 25th percentile to $4,507 at the 90th percentile, depending on the home’s assessed value and the rates applied.
Median Diamond Tax Bill
$1,587
Median Whitman County Tax Bill
$1,761
Median Washington Tax Bill
$4,512
Median United States Tax Bill
$3,209
Property Tax Bills Across Diamond, Whitman County, Washington
| Zip | 10th Percentile | 25th Percentile | Median Tax Bill | 75th Percentile | 90th Percentile |
|---|---|---|---|---|---|
| 99111 | $447 | $900 | $1,587 | $2,572 | $4,507 |
Source: Ownwell
Don't miss the deadline to appeal!
Dates | |
|---|---|
| Appeal Deadline | July 1 |
Links | |
|---|---|
| Whitman Tax Assessor | |
| Website | terrascan.whitmancounty.net |