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Updated 2025 Tax Year

Cassia County
Property Tax Guide

Everything you need to know about property taxes in Cassia County, ID. 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
~0.501% effective rate, varies significantly by taxing district location
Exemptions
4+ Available
Section 1

How Property Tax Works

Cassia County, Idaho operates under a property tax system that funds essential local services including schools, roads, fire protection, and county operations. The county's effective property tax rate for 2025 is approximately 0.501%, though this represents a base rate that varies significantly by location within the county due to special taxing districts such as school districts, highway districts, and other local improvement districts.

Property taxes in Cassia County are assessed annually based on market value as determined by the County Assessor's office. The actual tax rate you pay depends on your specific location within the county, as different areas are served by different combinations of taxing districts. Rural properties may have different district combinations than urban properties, resulting in varying effective tax rates across the county.

Section 2

What Makes Up Your Tax Bill

ComponentRateDescription
Base County Rate0.501%Core county services and operations
School District LevyVariesLocal school district operational funding
Supplemental School Levy$14.13 per $100KJoint School District No. 151 supplemental levy
Highway DistrictVariesRoad maintenance and improvements
Fire DistrictVariesFire protection services
Cemetery DistrictVariesCemetery maintenance and operations

Rates shown are for FY 2025-2026. Your actual combined rate depends on which special taxing districts serve your property location. Contact the Cassia County Assessor's office for your specific district combination and total effective rate.

Section 3

When Are Property Taxes Due?

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

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 Cassia County are additional property tax bills issued when there are changes to property ownership, new construction, or property improvements that increase assessed value during the tax year. These taxes cover the difference between what was originally assessed and the new assessed value, prorated for the remaining months in the tax year.

For example, if you complete a home addition worth $50,000 in March, you would receive a supplemental tax bill covering the additional tax on that $50,000 for the remaining 9 months of the tax year. The supplemental tax would be calculated as: ($50,000 × 0.501% × 9/12 months = $187.88). Supplemental tax bills are issued separately from your regular annual property tax bill and have their own due dates.

Example Calculation

Example 1: $300,000 Home

  • Assessed Value: $300,000
  • Homeowner's Exemption Applied: -$150,000 (requires application)
  • Net Taxable Value: $150,000
  • Annual Tax (0.501%): $753
  • Monthly Escrow: $63

Example 2: $600,000 Home

  • Assessed Value: $600,000
  • Homeowner's Exemption Applied: -$150,000 (requires application)
  • Net Taxable Value: $450,000
  • Annual Tax (0.501%): $2,255
  • Monthly Escrow: $188

Example 3: $1,000,000 Home

  • Assessed Value: $1,000,000
  • Homeowner's Exemption Applied: -$150,000 (requires application)
  • Net Taxable Value: $850,000
  • Annual Tax (0.501%): $4,259
  • Monthly Escrow: $355

Note: These examples use the base county rate and assume qualification for homeowner's exemption. Actual rates vary by special district combinations and require application for credits.

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Section 5

Escrow & Property Taxes

Most mortgage lenders in Cassia County require property tax escrow accounts for borrowers with less than 20% down payment. Your lender collects 1/12 of your estimated annual property tax bill each month along with your mortgage payment. The lender then pays your property tax bills directly to Cassia County when they become due.

Escrow accounts are typically analyzed annually, and your monthly payment may be adjusted based on actual tax bills and account balance. Since Cassia County property taxes are due December 20th annually, with an option to pay in two installments (first half by December 22nd, second half by July 1st), your lender will coordinate payments according to this schedule. You should receive annual escrow statements showing tax payments made on your behalf and any adjustments to your monthly escrow amount.

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Section 6

Frequently Asked Questions

Q: When are property taxes due in Cassia County for FY 2025-2026? A: Property taxes are due December 20, 2025. You can pay the full amount by December 22, 2025, or pay in two installments: first half by December 22, 2025, and second half by July 1, 2026.

Q: What tax credits are available and do I need to apply? A: The primary tax credit is the Homeowner's Exemption, which can reduce taxable assessed value by up to $150,000 for owner-occupied homes. This credit requires application and is not automatic. Additional Property Tax Relief (ATR) may also be available. Contact the Cassia County Assessor for applications.

Q: How does the Homestead credit work? A: Idaho's homestead exemption caps assessment increases on owner-occupied homes, limiting year-over-year assessment growth. This does not reduce market value but limits how much your assessed value can increase annually. You must file an application to qualify.

Q: When are properties reassessed? A: Cassia County assesses properties annually. Assessment notices are typically mailed in spring. If you disagree with your assessment, you can appeal to the Board of Equalization by the deadline specified on your notice.

Q: What are the penalties for late payment? A: Late payments incur interest at 6% annually from the original due date until paid. Additional late charges apply after December 22nd for the first installment and after July 1st for the second installment.

Q: Can I pay property taxes online? A: Yes, Cassia County offers online payment options through the County Treasurer's office. Contact Cassia County Treasurer Laura Greener's office for online payment portal access and accepted payment methods.

Q: Why do tax rates vary within Cassia County? A: Different areas of the county are served by different combinations of special taxing districts (school, fire, highway, cemetery districts). Your total tax rate is the sum of all districts that serve your property location.

Q: What triggers a supplemental tax bill? A: Supplemental taxes are issued for new construction, property improvements, ownership changes, or other events that increase assessed value during the tax year. These bills are prorated for the remaining months in the tax year.

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
PTR_Tax Form-40.pdfcassia.gov
02
Tax Doc
2025 average property tax ratestax.idaho.gov
03
Tax Doc
APPLICATION FOR PROPERTY TAX REDUCTION FOR ...cassia.gov
04
County
Cassia County, Idaho - Treasurercassia.gov
05
Treasurer Dutiescassia.gov
06
County
Cassia County, Idaho - Important Datescassia.gov
07
Assessor Propertycassia.gov
08
Transaction Verification/ Homeowner's Exemption ...cassia.gov
09
Tax Doc
Homeowner's Property Taxcassia.gov
10
VOTE BOTH SIDES BALLOT MEASURES CITY OF ...cassia.gov
All sources verified as of 2025 Tax Year

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