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Updated 2025 Tax Year

Cowlitz County
Property Tax Guide

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

10 Official Sources
8 min read
Quick Facts
Tax Rate
Average 0.921% (ranges 0.8%-1.1% depending on special taxing districts)
1st Due
Apr 30
2nd Due
Oct 31
Exemptions
5+ Available
Section 1

How Property Tax Works

Cowlitz County, Washington operates under a property tax system that serves as the primary funding mechanism for essential local services including schools, roads, emergency services, and general county operations. Property taxes in Cowlitz County are calculated based on assessed value multiplied by the applicable tax rate, which varies significantly by location within the county due to different combinations of special taxing districts.

For the 2025 tax year, the average property tax rate in Cowlitz County is approximately 0.921%, though actual rates can range from below 0.8% to over 1.1% depending on your specific location and the special districts that serve your property. These districts may include school districts, fire protection districts, library districts, port districts, and various other municipal services. Property owners should note that their exact tax rate depends on which combination of these taxing jurisdictions their property falls within, making it essential to verify your specific rate with the Cowlitz County Assessor's Office.

Section 2

What Makes Up Your Tax Bill

ComponentApproximate RateDescription
County Current Expense0.15% - 0.25%General county operations and services
County Roads0.08% - 0.12%Road maintenance and transportation infrastructure
School Districts0.35% - 0.55%Local school district operations and bonds
State School Levy0.20% - 0.30%State-mandated school funding
Fire Protection0.05% - 0.15%Fire and emergency medical services
Municipal Services0.00% - 0.20%City services (if within city limits)
Special Districts0.02% - 0.10%Libraries, ports, parks, utilities

Total Combined Rate: 0.85% - 1.67% (Levy Year 2025)

Note: These rates apply to Fiscal Year 2025-2026 and vary significantly by location within Cowlitz County. Your actual tax rate depends on which specific combination of taxing districts serve your property address.

Section 3

When Are Property Taxes Due?

For the 2025/2026 tax year in Cowlitz 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 Cowlitz County are additional property tax bills issued when there is a change in property ownership, completion of new construction, or significant improvements that increase the assessed value of a property mid-year. These taxes cover the difference between what was originally assessed and what should have been assessed for the portion of the tax year after the change occurred.

For example, if you purchase a newly constructed home in March that wasn't on the previous year's tax roll, you would receive a supplemental tax bill covering April through December of that tax year. The supplemental tax is calculated by taking the difference between the new assessed value and the previous assessed value (or zero for new construction), multiplying by your property's tax rate, and prorating for the remaining months in the fiscal year. If a new $400,000 home is completed in June, the supplemental tax would be approximately ($400,000 × 0.00921 × 7/12 months) = $2,149 for the remaining seven months of that tax year.

Example Calculation

Example 1: $300,000 Home

  • Market Value: $300,000
  • Assessed Value: $300,000
  • Senior Citizens Tax Credit Applied: -$1,500 (if qualified and applied)
  • Net Taxable Value: $298,500
  • Tax Rate: 0.921%
  • Annual Tax: $2,749
  • Monthly (if escrowed): $229

Example 2: $600,000 Home

  • Market Value: $600,000
  • Assessed Value: $600,000
  • Homestead Credit Applied: Assessment increase limited to prior year + 10%
  • Net Taxable Value: $600,000
  • Tax Rate: 0.921%
  • Annual Tax: $5,526
  • Monthly (if escrowed): $461

Example 3: $1,000,000 Home

  • Market Value: $1,000,000
  • Assessed Value: $1,000,000
  • Disabled Persons Credit Applied: -$2,000 (if qualified and applied)
  • Net Taxable Value: $998,000
  • Tax Rate: 0.921%
  • Annual Tax: $9,193
  • Monthly (if escrowed): $766

Note: All tax credits require annual application and qualification verification. Credits are not automatically applied.

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Section 5

Escrow & Property Taxes

Most mortgage lenders in Cowlitz County require property tax escrow accounts for borrowers with less than 20% equity. Your lender collects approximately 1/12 of your annual property tax bill with each monthly mortgage payment and deposits these funds into an escrow account. The lender then pays your property taxes directly to Cowlitz County when they become due on April 30th and October 31st each year.

Lenders typically conduct annual escrow analyses to ensure adequate funds are being collected. If property taxes increase due to reassessment or rate changes, your monthly escrow payment will be adjusted accordingly. Property owners should verify that their lender has paid taxes on time by checking with the Cowlitz County Treasurer's Office, as late payments can result in penalties and interest charges even when using escrow services. You can request escrow account statements from your lender and monitor payments through the county's online property tax portal.

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 Cowlitz County? A: Property taxes are due in two installments: April 30th for the first half and October 31st for the second half of each fiscal year. Payments are considered late if received after 4:30 PM on the due date.

Q: What tax credits are available and how do I apply? A: Cowlitz County offers several tax credits including Senior Citizens & Disabled Persons Credit, Destroyed Property Credit, and Historic Property Credits. All credits require annual application through the Cowlitz County Assessor's Office and must be submitted by specific deadlines, typically by December 31st of the assessment year.

Q: How does the Homestead Credit work? A: Washington's Homestead Credit limits annual assessment increases on your primary residence to a maximum of 10% per year, even if market value increases more. You must file an application with the county assessor and reapply periodically to maintain this benefit. It does not reduce market value but caps assessment growth.

Q: How often are properties reassessed in Cowlitz County? A: Properties are reassessed annually based on market conditions as of January 1st each year. The assessed value becomes effective for taxes due the following year. Property owners receive assessment notices in late spring and have until July 1st to appeal.

Q: What are the penalties for late property tax payments? A: Late payments incur penalties starting at 3% for the first month, increasing to 8% after two months, plus additional interest charges. Properties become subject to foreclosure proceedings if taxes remain unpaid for three years.

Q: Can I pay property taxes online? A: Yes, Cowlitz County offers online payment options through their official website. You can pay by electronic check or credit card, though credit card payments may include processing fees. Automatic payment plans are also available.

Q: Why do property tax rates vary within Cowlitz County? A: Tax rates vary because different areas are served by different combinations of special taxing districts such as school districts, fire districts, library districts, and municipal services. Each district sets its own levy rate based on local service needs.

Q: How do special district taxes affect my bill? A: Special districts provide specific services like fire protection, libraries, or parks to defined geographic areas. If your property receives these services, you pay the applicable district taxes in addition to county and state taxes. These rates are included in your total property tax calculation.

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