Verified July 2026 · By Oleg Kachko · Reviewed for accuracy against primary state and county sources
Washington County property tax costs the typical homeowner about $4,929 a year, on a median home value of $588,000 – an effective rate of about 0.86%. That is above the national average annual bill of $4,271. This page shows you where that number comes from, who actually sets it, the deadline to challenge it, and the exemptions you may be leaving on the table.
Washington County property tax at a Glance
- Effective property tax rate: 0.86%
- Median annual bill: $4,929
- Median home value: $588,000
- Who assesses your home: Washington County Assessor
- Appeal deadline: December 31
On this page
Washington County property tax: the real numbers
Property tax is the most local tax there is. Two homes of the same value in different counties – sometimes in different towns of the same county – can carry very different bills, because the rate is the sum of every overlapping district that taxes you: the county, the town or city, the school district, and often fire, library or water districts on top. So the washington county property tax figure below is an average across the whole county – your own bill depends on which districts you sit inside.
| Figure | Washington County | National |
|---|---|---|
| Median annual property tax bill | $4,929 | $4,271 |
| Effective property tax rate | 0.86% | about 0.90% |
| Median home value | $588,000 | – |
Source: U.S. Census Bureau American Community Survey (5-year), the same dataset the Tax Foundation uses. The effective rate is total real-estate taxes paid divided by total owner-occupied home value – so it reflects what people actually pay, not the headline millage rate.
Who actually sets your washington county property tax value
Your assessed value is set by Washington County Assessor. That office does not set your tax rate – the county board, your city, and your school district each set their own, and your bill is the sum. So the assessor can only be argued with about one thing: what your home is worth. That is exactly what an appeal is.
How often your washington county property tax value is reassessed:
County assessors set a real market value each year as of January 1, but tax is based on the Maximum Assessed Value, which Measure 50 limits to 3% growth per year (unless there’s new construction).
How to appeal your washington county property tax assessment
⚠ The deadline — miss it and you usually wait a full year
December 31
File a petition with the county Board of Property Tax Appeals (BOPTA) by December 31 (tax statements are mailed by October 25). The board hears cases January-April 15; appeal a decision to the Oregon Tax Court within 30 days. Note an appeal only lowers your tax if it pushes real market value below your capped assessed value.
Almost every washington county property tax appeal comes down to one claim: the assessor thinks my home is worth more than it really is. Everything below is about proving that.
Do this first, before you file anything: ask for your property record card and read it. A surprising share of assessments are simply wrong on the facts – the wrong square footage, a bathroom you do not have, a finished basement that is bare concrete, a garage that was torn down. Factual errors are the easiest appeals to win, because there is nothing to argue about.
Then build the one thing that actually wins appeals: comparable sales. Find three to five homes near you, as similar as you can get on size, age, and condition, that sold recently for less than your assessed value. Not listings – sales. Not Zillow estimates – recorded sales. Boards ignore opinions and respond to comps.
A successful washington county property tax appeal does not change your tax rate – it lowers the value the rate is applied to, which lowers the bill for as long as the new value stands.
Appeals are heard by the County Board of Property Tax Appeals (BOPTA), then the Oregon Tax Court (Magistrate Division). In most places there is a free, informal step first – a conversation or a paper review with the assessor – and it resolves a large share of cases without a hearing. Take it. It costs you nothing and it is the fastest way to win.
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One honest warning: an appeal reviews your value, and a review can go up as well as down. That is uncommon when you bring real comparable sales, and it is exactly why you check your comps before you file.
Where to go: find your office through Oregon Dept of Revenue, which lists the assessing office for every county in Oregon.
Washington County property tax exemptions you may qualify for
This is where most homeowners quietly overpay their washington county property tax. Exemptions are almost never applied automatically – you have to claim them, and many people simply never do. It is worth ten minutes of your time to check.
HOMESTEAD: No flat exemption; the 3% assessed-value cap and $15/$1,000 rate cap are the protections. Confirm with your county assessor. | SENIOR: Defers the full tax (income-limited); not forgiven. Confirm the current income limit with the Oregon Dept of Revenue. | VETERAN: About $28,000 of assessed value exempt (2026, indexed). Confirm with your county assessor. | DISABILITY: Deferral (income-limited). Confirm with your county assessor.
Homestead: Oregon has no general homestead exemption. Its main homeowner protection is structural: under Measure 50, a home’s Maximum Assessed Value (the value it’s taxed on) can rise no more than 3% per year, and under Measure 5 the tax rate is capped at $15 per $1,000 of real market value. Your tax is figured on the LOWER of market value or the capped assessed value.
Senior / over-65: Senior & Disabled Property Tax Deferral (ORS 311.668): the state pays your property taxes and records a lien, repaid with interest (about 6%) when you sell, move, or pass away. For owners 62+ or disabled who have owned and lived in the home 5+ years, with household income under the yearly limit (about $58,000-$70,000). Apply by April 15 with the county assessor; recertify every two years. It’s a deferral, not an exemption.
Veteran: Disabled Veteran / Surviving Spouse Exemption (ORS 307.250): exempts roughly $28,000 of assessed value (service-connected; a bit less for non-service, indexed +3%/year) for an honorably discharged veteran with a 40%+ disability, or the surviving spouse. Apply with the county assessor by April 1.
Disability: Disabled homeowners can use the Senior & Disabled Deferral above (defer the tax, income-limited). Oregon’s disability property relief is otherwise channeled through the disabled-veteran exemption; there is no broad disability exemption.
Common questions about washington county property tax
Why did my washington county property tax bill go up when I did nothing to the house?
Two different things can raise a bill: your assessed value went up, or a taxing district raised its rate. They are separate, and only the first one can be appealed. Your notice will show which changed.
Is it worth appealing my washington county property tax?
Ask one question: would a similar home near mine sell for less than the value the assessor has put on mine? If yes, you have a case, it is usually free to file, and in many places the informal review settles it without a hearing.
Do I need to hire someone to appeal?
No. The informal review and the local board are built for ordinary homeowners to use themselves, and there is normally no fee. Appeal services exist and can be worth it for some people, but you are not required to use one and you should never be told you are.
How is my washington county property tax bill actually calculated?
Your assessed value is multiplied by the combined rate of every district that taxes you, then any exemptions you have claimed are subtracted. That is why two neighbours can pay different amounts on identical homes – one of them claimed an exemption the other never did.
More on Oregon property tax
- Oregon property tax rates — how Washington County compares with every other county in the state.
- How to win your Oregon property tax appeal — the evidence that works and what to say at the hearing.
- Oregon property tax exemptions — who qualifies, how much each one saves, and how to apply.
- Oregon property tax due dates — when the bill is due and what happens if you are late.
- Property tax by state — every state, side by side.
The bottom line on washington county property tax
Do two things this week. First, pull your property record card and check the facts – square footage, rooms, condition. Second, check whether you are claiming every exemption you are entitled to, because most people are not. If your washington county property tax value looks higher than what a similar home nearby would actually sell for, you have grounds to appeal – and the only thing that can stop you is the deadline above.
Where our washington county property tax figures come from
- U.S. Census Bureau, American Community Survey — the rate, median bill and median value on this page.
- Tax Foundation, Property Taxes by State and County — the same dataset and method.
- Oregon Dept of Revenue — the office that can confirm your value, your exemptions and your deadline.
- Oregon Dept of Revenue (oregon.gov/dor); ORS chs. 307-311; Measures 5 & 50; county assessor sites
Informational only. Know Property Tax is not a government agency, not a county assessor, and not a tax-appeal service, and this is not legal, tax, or financial advice. Property tax rates, median bills, exemption amounts, and deadlines change every year, and every property is different. Any figure shown here is illustrative. Confirm your rate, your exemptions, and above all your appeal deadline with the office named on this page before you act.
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