Washington County Property Tax Increases: Compression, Appeals, and Relief

Washington County property taxes rose 11.7 percent for the 2025–26 tax year, adding roughly $183 million to a total tax roll of $1.742 billion.¹ A Washington County property tax increase that large almost never comes from one source. The 3 percent cap on assessed value growth, a wave of new construction that includes large industrial data centers, and voter-approved levies all landed in the same year. Knowing which of these is driving your bill is the first step to deciding whether to appeal, apply for an exemption, or simply pay early and capture the discount.

What Is Actually Driving the Increase

Three forces explain most of what shows up on a 2025–26 statement.

The 3 Percent Cap Does Not Work the Way Most People Think

Oregon’s Measure 50 caps the Maximum Assessed Value of most properties at 3 percent annual growth.² Your taxable Assessed Value is the lower of that Maximum Assessed Value or the Real Market Value.¹ In a flat or softening market, a home’s Real Market Value can drop below the Maximum Assessed Value, and the Assessed Value then climbs back up toward the cap. That climb can exceed 3 percent in a single year. Homeowners who assume the cap locks in a steady bill are often the ones most surprised by the jump.

New Construction, Including Data Centers

New homes, commercial buildings, and industrial facilities enter the tax roll without a Maximum Assessed Value history to limit them. Washington County specifically pointed to large data center expansions and new construction activity as contributors to the 2025–26 increase.¹ That added value doesn’t push up your individual rate directly, but growth tends to arrive alongside bond and levy measures to fund the schools, roads, and emergency services the new population needs.

Voter-Approved Levies and Bonds

Local option levies and general obligation bonds are the most common cause of a sudden jump between one year’s statement and the next. Once voters approve a measure, the cost is spread across every property in the taxing district as an added rate per $1,000 of assessed value. Oregon law governs how these are calculated and distributed.³ A single Washington County property can sit inside overlapping districts for the county, a city, a school district, a community college, a fire district, a library district, and more. Any one of them can add a rate.

Compression: The Limit That Can Reduce What You Pay

Measure 5 caps the total operating tax rate against your Real Market Value at $5 per $1,000 for education and $10 per $1,000 for general government.⁴ When the combined rates in a category exceed that ceiling, compression kicks in and each district’s rate in the category is cut proportionally until the total falls back within the cap. Properties where Real Market Value sits well above Assessed Value get the biggest benefit, because the Measure 5 ceiling is calculated against the higher figure. If your statement shows compression savings, that is the mechanism at work.

What Can Reset Your Assessed Value Beyond 3 Percent

The 3 percent annual limit on Maximum Assessed Value has specific statutory exceptions. If any of these apply to your property, your taxable value can rise by more than 3 percent in a single year:⁵

New construction or improvements, such as an added room, a new garage, or a finished basement.
Subdivision or partition of a parcel into smaller lots.
Rezoning combined with a use consistent with the new zoning.
Omitted property discovered by the assessor and added to the rolls.
Loss of an exemption or special assessment, such as farmland leaving a special program.
Lot line adjustments, though the combined assessed value of the affected parcels cannot exceed what existed before the change.

The reverse is also true. If fire or a natural disaster reduces your property’s Real Market Value, the Maximum Assessed Value must be reduced to reflect that loss. You don’t have to appeal to receive this adjustment, but confirming the assessor actually applied it is worth the phone call.⁵

How to Appeal if the Valuation Looks Wrong

If the Real Market Value on your statement seems too high, you can challenge it through the Property Value Appeals Board, formerly the Board of Property Tax Appeals. There is no filing fee in Washington County.⁶

Build the Evidence First

The board only looks at what you give it. The most persuasive evidence is recent sales of comparable nearby properties that closed around January 1 of the assessment year, with adjustments for differences in lot size, square footage, condition, and location. A fee appraisal from a licensed appraiser dated near January 1 also carries real weight. For physical damage or deferred maintenance, written repair estimates or contractor bids, plus photographs, help the board see what sales data alone can’t show.

File the Petition

Petitions must be postmarked or hand-delivered to the county clerk no later than December 31. If December 31 falls on a weekend or holiday, the deadline moves to the next business day. The window opens in late October when statements go out. Forms are on the Washington County website or available by calling 503-846-3854.⁶ You’ll need your property account number from the tax statement, your proposed value, and a written explanation of why the county’s figure is wrong.

Hearings and the Decision

Hearings run on weekdays from the first Monday in February through April 15.⁷ You present evidence, answer questions, and receive a written decision in the mail. A favorable decision adjusts your Assessed Value downward. If you disagree with the board, you have 30 days from the mailing date of the order to appeal to the Magistrate Division of the Oregon Tax Court.⁸ Miss that window and the order is final.

One boundary worth noting: an appeal challenges the Real Market Value, not the levy rates or the bond measures that voters approved. If your bill rose because a new school bond passed, an appeal won’t help.

Programs That Can Lower or Delay What You Owe

Washington County administers several exemption and deferral programs through the assessor’s office, each with its own eligibility rules.⁹

Senior and Disabled Homeowner Deferral

Qualifying seniors and disabled homeowners can have the state pay their property taxes directly to the county. The deferred amount becomes a lien repaid when the home is sold or ownership transfers. For 2026, household income must be $70,000 or less (based on 2025 income), and the home’s Real Market Value must fall below a threshold tied to county medians, with a minimum cap of $301,000. Seniors must be at least 62 by April 15 of the filing year. Applications are due April 15, with a late window through December 1 that carries a fee of $20 to $180.¹⁰ Recertification is required every two years.

Disabled Veteran Exemption

Veterans with a service-connected disability rating of 40 percent or more can exempt either $27,092 or $32,512 of their homestead’s assessed value, depending on the nature and documentation of the disability. The exemption amounts rise 3 percent each year. The property must be the veteran’s primary residence, and the discharge must be under honorable conditions. Unremarried surviving spouses and those who have not entered a new domestic partnership also qualify. The governing statutes are ORS 307.250 through 307.283.¹¹

Other Exemptions

Washington County also runs an active duty military exemption for deployed Oregon National Guard or Reserve members, a surviving spouse of a public safety officer exemption, and a surviving spouse of a veteran exemption.⁹ Each has its own form and deadline. Call the assessor’s office at 503-846-8741 to confirm eligibility before the filing window closes.

Payment Timing: Discounts and the Cost of Being Late

Oregon splits the annual bill into three installments:¹²

First third due November 15.
Second third due February 15.
Final third due May 15.

Paying the full year by November 15 earns a 3 percent discount. Paying two-thirds by that date earns a 2 percent discount on the amount paid.¹² On a $6,000 bill, the full-payment discount is $180. If your total tax is under $40, the installment option isn’t available and the whole amount is due at once.

Missing a deadline triggers interest at 1⅓ percent per month, or 16 percent annually, on the unpaid balance, starting the month after the due date.¹² The first-third installment begins accruing interest on December 15 if unpaid, but the November discount is gone the moment that date passes.

If taxes stay unpaid for three years from the earliest delinquency date, the county can begin foreclosure.¹³ Proceedings start three months after the end of the third year of delinquency and are filed against the property itself rather than the owner personally, with any other unpaid special assessments bundled into the same action.¹⁴ The three-year clock sounds forgiving, but 16 percent annual interest means the balance owed well before foreclosure can be far larger than the original bill.

1
Washington County. 2025-26 Property Tax Statement
2
Benton County Assessment, Oregon. How Are Taxes Calculated?
3
Oregon Revised Statutes. Oregon Revised Statutes 310.202 – Definitions for ORS 310.200 to 310.242
4
Oregon State Legislature. The New Property Tax System
5
Oregon Department of Revenue. Maximum Assessed Value Manual
6
Washington County, OR. Property Value Appeals
7
Washington County. Property Value Appeals Board (Formerly BoPTA)
8
Oregon Tax Court. Tax Appeals Oregon Tax Court
9
Washington County. Exemptions and Deferrals
10
Oregon Department of Revenue. Oregon Property Tax Deferral for Disabled and Senior Homeowners
11
Oregon Department of Revenue. Disabled Veteran or Surviving Spouse Property Tax Exemption
12
Oregon Public Law. ORS 311.505 – Due Dates; Interest on Late Payments
13
Oregon Public Law. ORS 312.010 – When Real Property Subject to Tax Foreclosure
14
Oregon State Legislature. ORS Chapter 312 – Tax Liens and Tax Deeds