Washington County, OR Property Tax: $4,852/yr (2026)
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The effective property tax rate in Washington County is 0.87% of assessed home value. On a home at the county median value of $558,500, that works out to about $4,859 per year, or $405 per month. Washington County is located in northern Oregon, and is home to approximately 600,266 residents.
About Washington County
Washington County covers approximately 724.3 square miles in Oregon. The county is home to about 600,266 residents living in roughly 240,409 housing units, of which 58.8% are owner-occupied. The median household income is $104,434, and the median home was built in 1990.
Washington County borders Clackamas County, Clatsop County, Columbia County, Multnomah County, Tillamook County — useful comparisons if you're considering nearby areas with potentially different tax rates.
How Property Taxes Work in Oregon
Property taxes in Oregon are administered at the county level. Each county sets a millage rate applied to the assessed value of real property — the effective rate above accounts for any partial assessments and exemptions already built into the local tax base. Assessed value can differ meaningfully from current market value depending on how often the county reassesses and what fraction of market value it uses.
Most counties in Oregon offer exemptions that reduce the taxable assessed value: homestead exemptions for primary residences, senior exemptions, disability exemptions, and veteran exemptions are common. These reduce your effective rate below the county-wide average shown here. Contact the Washington County Assessor's office to learn which exemptions apply to your property and when to file.
Washington County vs. Neighboring Counties
| Location | Eff. Rate | Median Home | Annual Tax |
|---|---|---|---|
| Washington County, OR | 0.87% | $558,500 | $4,859 |
| Oregon state average | 0.78% | — | $4,356* |
| Clackamas County | 0.87% | $577,900 | $5,051 |
| Clatsop County | 0.70% | $437,800 | $3,084 |
| Columbia County | 0.75% | $390,600 | $2,948 |
| Multnomah County | 0.96% | $528,000 | $5,061 |
| Tillamook County | 0.60% | $408,600 | $2,449 |
| US national average | 1.10% | $281,900 | $3,101 |
*State average annual tax computed at Washington County's median home value of $558,500. Source: US Census ACS 2023 5-year estimates.
Frequently Asked Questions
How does Washington County's property tax rate compare to the rest of Oregon?
At 0.87%, Washington County is higher than the Oregon state average of 0.78%. On a home at the county median of $558,500, that means about $4,859 per year — versus $4,356 at the state average rate, a difference of $503 per year. Compared to the national average of 1.10%, Washington County is below average.
What's a typical annual property tax bill in Washington County?
For a home at the county median value of $558,500, the annual property tax in Washington County is approximately $4,859 — or about $405 per month. For a home worth $837,750, expect around $7,288 per year. For a $1,117,000 home, approximately $9,718 per year. Use the calculator above to estimate taxes for any assessed value.
Where do I appeal a Washington County property tax assessment?
Property assessment appeals in Washington County are handled by the Washington County Assessor's office. Most jurisdictions require filing within 30–90 days of receiving your assessment notice — confirm the specific deadline with the assessor's office before submitting, as deadlines and procedures vary by county. A successful appeal can reduce your assessed value and lower your tax bill for the current and future tax years.
What exemptions are available in Washington County?
Oregon counties commonly offer homestead exemptions for owner-occupied primary residences, senior citizen exemptions for qualifying homeowners aged 65 and older, exemptions for disabled residents, and veterans' exemptions. Each exemption reduces your assessed taxable value, which in turn reduces your effective tax rate below the county-wide 0.87% shown here. Contact the Washington County Assessor's office to confirm which exemptions are available and the application deadlines.
Data sources: US Census Bureau ACS 2023 5-Year Estimates, US Census Gazetteer (2024), County Adjacency File