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Updated 2025 Tax Year

Adams County
Property Tax Guide

Everything you need to know about property taxes in Adams County, WA. Rates, due dates, exemptions, and how it affects your monthly payment.

10 Official Sources
8 min read
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Quick Facts
Tax Rate
0.63% to 1.26% of assessed value, varies by taxing district combination
1st Due
Apr 30
2nd Due
Oct 31
Exemptions
5+ Available
Section 1

How Property Tax Works

Adams County, Washington operates on a property tax system that serves as the primary funding mechanism for essential local services including schools, roads, emergency services, and county operations. Property owners in Adams County face an effective tax rate of approximately 0.63% to 1.26% of assessed value, depending on their location within the county and the specific combination of taxing districts that serve their property.

The actual tax rate you pay varies significantly based on your property's location within Adams County due to overlapping special taxing districts such as school districts, fire districts, hospital districts, and other local improvement districts. Each district adds its own levy to fund specific services, meaning two properties of equal value in different parts of the county may have substantially different tax bills. The county assessor determines property values annually, typically assessing at market value as of January 1st each year.

Section 2

What Makes Up Your Tax Bill

Based on FY 2025 levy rates, Adams County property taxes consist of multiple components:

ComponentRate (per $1,000)Description
County Regular$2.47General county operations, roads, courthouse
State Regular$2.70State-mandated levies
School Districts$8.50-$12.00Varies by district - maintenance & operations
School Bonds/Levies$0.00-$4.50Capital improvements, varies by district
Fire Districts$0.85-$1.50Emergency services, varies by district
Hospital Districts$0.75-$1.25Public hospital services
Port Districts$0.45Economic development (where applicable)
Total Range$15.72-$24.97Equivalent to 1.57%-2.50% effective rate

These rates apply to the 2025 tax year (due in 2026). Your specific rate depends on which combination of districts serve your property location. Contact the Adams County Assessor at 509-659-3200 for your exact district combination.

Section 3

When Are Property Taxes Due?

For the 2025/2026 tax year in Adams County, property taxes are due in two installments:

First Installment
Apr 30
Delinquent after Dec 10
Second Installment
Oct 31
Delinquent after Apr 10
Pro tip: If you pay through mortgage escrow, your lender splits these payments across your monthly mortgage. If you pay directly, set calendar reminders to avoid late penalties.
Section 4

Supplemental Tax Bills

Supplemental taxes in Adams County occur when there are mid-year changes to property ownership or improvements that increase assessed value. The most common triggers include property sales that result in reassessment, completion of new construction, or major renovations that add significant value to existing structures.

When a supplemental assessment is issued, the additional tax is calculated based on the difference between the old and new assessed values, prorated for the remaining months in the tax year. For example, if you complete a $50,000 home addition in July and your area's tax rate is 2.0%, you would owe approximately $500 × 6/12 months = $250 in supplemental taxes for that year. Supplemental tax bills are typically mailed within 30-60 days of the triggering event and become due 30 days after the bill date.

Example Calculation

Here are three examples showing annual property tax calculations for Adams County (using a mid-range rate of 2.1%):

Example 1: $300,000 Home

  • Assessed Value: $300,000
  • Less: Senior Citizens/Disabled Persons Credit (if applicable): -$70,000
  • Net Taxable Value: $230,000
  • Annual Tax: $230,000 × 0.021 = $4,830
  • Monthly Escrow: $402.50

Example 2: $600,000 Home

  • Assessed Value: $600,000
  • Less: Regular Homestead Credit (if applicable): -$60,000
  • Net Taxable Value: $540,000
  • Annual Tax: $540,000 × 0.021 = $11,340
  • Monthly Escrow: $945.00

Example 3: $1,000,000 Home

  • Assessed Value: $1,000,000
  • Less: No applicable credits at this value level
  • Net Taxable Value: $1,000,000
  • Annual Tax: $1,000,000 × 0.021 = $21,000
  • Monthly Escrow: $1,750.00

Note: All tax credits require application and income/eligibility verification. Credits shown are examples and may not apply to all properties.

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Section 5

Escrow & Property Taxes

Most mortgage lenders in Adams County require borrowers to maintain an escrow account for property taxes, collecting monthly payments as part of your mortgage payment and paying taxes directly to the county when due. Lenders typically collect 1/12th of your annual tax bill each month, plus an additional cushion of up to two months' worth of taxes as required by federal law.

Your lender will receive tax bills directly from Adams County and should pay them by the November 15th due date each year. However, it's important to verify that payments are made correctly and on time, as you remain ultimately responsible for ensuring taxes are paid. If your escrow account has a shortage, your lender will typically spread the shortage over 12 months and adjust your monthly payment accordingly. Conversely, if there's an overage exceeding $50, you should receive a refund or credit toward future payments.

How HonestCasa Helps
  • Understand whether your escrow is set correctly
  • See how rising taxes will change your monthly payment
  • Plan ahead instead of being surprised by "shortage" letters
Section 6

Frequently Asked Questions

Q: When are property taxes due in Adams County? A: Property taxes for the 2025 tax year are due by November 15, 2025. Tax statements are mailed by October 25th. Payments must be postmarked by the due date to avoid penalties.

Q: What tax credits are available and do I need to apply? A: Several tax credits are available including Senior Citizens/Disabled Persons Credit, Regular Homestead Credit, and Veterans Disability Credit. ALL CREDITS REQUIRE APPLICATION and are not automatic. Contact the Adams County Assessor at 509-659-3200 for applications and deadlines.

Q: How does the Homestead Credit work? A: The Homestead Credit doesn't reduce your home's market value but rather limits annual assessment increases to protect against rapid tax increases. You must file an application and meet income requirements. This caps assessment growth, not the assessed value itself.

Q: When does the county assess property values? A: Adams County assesses all properties annually as of January 1st. Assessment notices are typically mailed by April 30th, and you have 60 days from the notice date to appeal if you disagree with the assessed value.

Q: What are the penalties for late payment? A: Interest begins accruing on December 1st at 1% per month on unpaid balances. Additional penalties may apply, and properties can eventually face tax foreclosure for non-payment.

Q: Can I pay my taxes online? A: Yes, Adams County offers online payment options through their official website. You can pay by electronic check or credit card, though credit card payments may include convenience fees.

Q: Why do special district taxes vary so much? A: Your property may be served by different combinations of school districts, fire districts, hospital districts, and other special purpose districts depending on your exact location. Each district sets its own levy rate based on local needs and voter approval.

Q: How do I find out which taxing districts serve my property? A: Contact the Adams County Assessor's office at 509-659-3200 or visit their office with your property address. They can provide a detailed breakdown of all taxing districts and their current rates for your specific location.

Verified Sources

Backed by 10 Official Government Sources

Every fact in this guide is sourced from official county, state, and federal documents.

01
Tax Doc
PROPERTY TAX STATISTICS 2025dor.wa.gov
02
Tax Doc
Itemized Property Tax Information - Auditorauditor.adamscounty01.us
03
County
Adams County Property Tax Administration Review Follow- ...dor.wa.gov
04
Businessco.adams.wa.gov
05
County
2022 Review of Property Tax Administration in Adams Countydor.wa.gov
06
County
2024 Adams County Levy Auditdor.wa.gov
07
Chapter 6.13 RCW: HOMESTEADSapp.leg.wa.gov
08
County
Official Local Voters' Pamphlet - Adams County, WAco.adams.wa.gov
09
County
County Assessor - Washington Department of Revenuedor.wa.gov
10
State
REAL ESTATE EXCISE TAX SUPPLEMENTAL STATEMENTco.adams.wa.gov
All sources verified as of 2025 Tax Year

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