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Updated 2025 Tax Year

Mason County
Property Tax Guide

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

10 Official Sources
8 min read
Quick Facts
Tax Rate
Varies by district - around 2.27% base rate with local additions depending on school district and special taxing districts
1st Due
Jun 1
2nd Due
Sep 1
Exemptions
5+ Available
Section 1

How Property Tax Works

Mason County property taxes fund essential local services including public schools, libraries, fire protection, parks, and county operations. The property tax system operates on a two-year assessment cycle, with properties reassessed every four years by township assessors and the Supervisor of Assessments. The county's 2025 tentative property assessment equalization factor is 1.0534, which helps determine the final tax rates.

Property tax rates in Mason County vary significantly by location within the county due to different combinations of taxing districts. While the state's average effective rate is approximately 2.27%, your actual rate depends on which school district, township, municipality, and special districts (fire protection, library, park, etc.) serve your property. Residential properties are assessed at 33.33% of fair market value, with the equalized assessed value (EAV) used to calculate your tax liability.

Section 2

What Makes Up Your Tax Bill

ComponentEstimated Rate RangeDescription
County0.3% - 0.5%General county operations, health, highways
Township0.1% - 0.3%Road maintenance, general assistance, assessor
School Districts4.0% - 6.5%Educational fund, operations & maintenance, bonds
Municipality0.8% - 1.5%City/village services (if applicable)
Fire Protection0.2% - 0.8%Fire department services
Library0.1% - 0.4%Public library operations
Other Special Districts0.1% - 0.5%Parks, drainage, conservation, etc.
Total Estimated Range5.6% - 10.0%Varies by specific location

Rates shown are for levy year 2025 and are applied to equalized assessed value (EAV). Final rates are determined after the Board of Review process concludes on November 24, 2025. Your actual rate depends on the specific combination of taxing districts serving your property.

Section 3

When Are Property Taxes Due?

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

First Installment
Jun 1
Delinquent after Dec 10
Second Installment
Sep 1
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 Mason County are triggered primarily by ownership changes, new construction, or improvements that increase a property's assessed value during the tax year. When these qualifying events occur, the County Assessor calculates the difference between the old and new assessed values and applies the current tax rate to determine additional taxes owed.

For example, if you purchase a home in Mason County and the new assessment reflects a higher market value than the previous assessment, you may receive a supplemental tax bill for the difference. Similarly, completing home improvements like additions, pools, or major renovations can trigger a supplemental assessment. These supplemental taxes are prorated based on the number of months remaining in the tax year from when the change occurred, ensuring you only pay for the period you owned the property at its new assessed value.

Example Calculation

Example 1: $300,000 Home with Homeowner Exemption

  • Market Value: $300,000
  • Assessment Ratio (33.33%): $99,990
  • Less Homeowner Exemption: -$10,000
  • Net Taxable EAV: $89,990
  • Tax Rate (7.5% example): × 0.075
  • Annual Tax: $6,749 | Monthly: $562

Example 2: $600,000 Home with Senior Citizen Exemption

  • Market Value: $600,000
  • Assessment Ratio (33.33%): $199,980
  • Less Homeowner Exemption: -$10,000
  • Less Senior Citizen Exemption: -$5,000
  • Net Taxable EAV: $184,980
  • Tax Rate (7.5% example): × 0.075
  • Annual Tax: $13,874 | Monthly: $1,156

Example 3: $1,000,000 Home with Homeowner Exemption

  • Market Value: $1,000,000
  • Assessment Ratio (33.33%): $333,300
  • Less Homeowner Exemption: -$10,000
  • Net Taxable EAV: $323,300
  • Tax Rate (8.0% example): × 0.08
  • Annual Tax: $25,864 | Monthly: $2,155

Note: All exemptions require annual application and are not automatic. Tax rates vary by location within Mason County.

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Section 5

Escrow & Property Taxes

Most mortgage lenders in Mason County require borrowers to maintain an escrow account for property taxes, collecting monthly payments along with principal and interest. Since Mason County property taxes are due in two installments (June 1 and August 1), your lender will accumulate funds throughout the year and pay the bills on your behalf when due.

Lenders typically conduct an annual escrow analysis to ensure adequate funds are collected, which may result in payment adjustments if taxes increase or decrease. You can verify your property tax amounts by accessing the Mason County Property Tax Search system or contacting the County Clerk's office. If you pay taxes directly without escrow, remember that the second installment due date is August 1, and mailed payments for the first installment are due within 30 days of the bill date if received late.

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 Mason County? A: Property taxes for fiscal year 2025 are due in two installments: June 1 and August 1. If the first installment bill is mailed late, it's due 30 days after the bill date.

Q: What tax credits are available and do I need to apply? A: Yes, ALL tax credits require annual application. Available credits include the Homeowner Exemption (reduces EAV by up to $10,000) and Senior Citizen Exemption ($5,000 EAV reduction for owners 65+ using form PTAX-324). Applications must be filed with the township assessor.

Q: How does the Homestead exemption work? A: The Homeowner Exemption reduces your property's equalized assessed value (EAV) by up to $10,000, not your market value. This is NOT automatic - you must apply annually with your township assessor to receive this benefit.

Q: When can I appeal my property assessment? A: The Board of Review appeal deadline for 2025 assessments is November 24, 2025. You can appeal if you believe your assessment is incorrect or inequitable compared to similar properties.

Q: What are the penalties for late payment? A: Late payments incur interest and penalties. Contact the County Collector's office for current penalty rates, as they can compound monthly and lead to tax sale procedures if left unpaid.

Q: Can I pay property taxes online? A: Check with the Mason County Clerk's office for current online payment options and accepted payment methods for property tax bills.

Q: Why do tax rates vary within Mason County? A: Different areas are served by different combinations of school districts, municipalities, fire districts, library districts, and other special taxing districts, each with their own tax rates that combine to create your total rate.

Q: How often are properties reassessed in Mason County? A: Mason County operates on a four-year reassessment cycle. Properties are reassessed by township assessors and the Supervisor of Assessments to reflect current market values and ensure equitable taxation across the county.

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