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Updated 2025 Tax Year

Johnson County
Property Tax Guide

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

10 Official Sources
8 min read
Quick Facts
Tax Rate
0.339276% base rate for 2025 levy year, varies by district with overlays
Exemptions
5+ Available
Section 1

How Property Tax Works

Johnson County, Illinois operates under the state's property tax system, which funds essential local services including schools, county government, townships, and various special districts. Property taxes in Johnson County are based on assessed values that are equalized by the Illinois Department of Revenue, with the county serving as the local assessment authority. The effective tax rates in Johnson County tend to be lower than the state average, with the county's base rate at 0.339276% for the 2025 levy year.

Actual property tax rates vary significantly by location within Johnson County due to the overlay of different special taxing districts, including school districts, municipalities, fire protection districts, and other local government entities. Property owners may see rates ranging from approximately 1.5% to 4% of assessed value depending on their specific location and the combination of taxing districts that serve their property. The Illinois Property Tax Extension Limitation Law (PTELL) helps control tax levy increases in most jurisdictions within the county.

Section 2

What Makes Up Your Tax Bill

ComponentRateDescription
Johnson County0.339276%Base county operations, sheriff, courts, roads
School DistrictsVaries by districtElementary and high school districts (rates vary significantly)
TownshipsVaries by townshipTownship road maintenance, general assistance
MunicipalitiesVaries by city/villageCity services for incorporated areas only
Fire Protection0.050000% (FMLR)Fire protection services where applicable
Library DistrictsVaries by districtPublic library services where established
Other Special DistrictsVariesCemetery, park, drainage, or other special purpose districts

Note: These rates apply to the 2025 levy year. The Forest Management and Land Resources (FMLR) district shows a rate of 0.050000%. Total effective rates typically range from 2.0% to 4.5% depending on your specific combination of taxing districts. Contact the Johnson County Clerk's office for your exact rate calculation.

Section 3

When Are Property Taxes Due?

For the 2025/2026 tax year in Johnson 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 Johnson County are additional property tax bills issued when there are changes to property ownership, new construction, or improvements that increase the assessed value mid-year. These taxes are calculated based on the difference between the old and new assessed values, multiplied by the applicable tax rate, and prorated for the portion of the tax year remaining after the change occurred.

Common triggers include new home construction, major renovations, additions, change of ownership that removes exemptions, or subdivision of property. For example, if you complete a $50,000 home addition in January and your total tax rate is 3.5%, you would receive a supplemental bill for approximately $1,750 ($50,000 × 3.5%) prorated for the remaining months in the tax year. Supplemental tax bills are typically issued within 60-90 days of the assessment change and have their own due dates separate from regular property tax installments.

Example Calculation

Example 1: $300,000 Home

  • Assessed Value (33.33%): $99,990
  • Less: Homeowner Exemption: -$10,000
  • Net Taxable Value: $89,990
  • Tax Rate (estimated): 3.2%
  • Annual Tax: $2,880
  • Monthly Escrow: $240

Example 2: $600,000 Home

  • Assessed Value (33.33%): $199,980
  • Less: Homeowner Exemption: -$10,000
  • Net Taxable Value: $189,980
  • Tax Rate (estimated): 3.4%
  • Annual Tax: $6,459
  • Monthly Escrow: $538

Example 3: $1,000,000 Home

  • Assessed Value (33.33%): $333,300
  • Less: Homeowner Exemption: -$10,000
  • Net Taxable Value: $323,300
  • Tax Rate (estimated): 3.6%
  • Annual Tax: $11,639
  • Monthly Escrow: $970

Note: Homeowner exemption requires annual application and reduces equalized assessed value by up to $10,000. Tax rates vary by specific taxing district combination. Examples use estimated composite rates for illustration.

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Section 5

Escrow & Property Taxes

Most mortgage lenders in Johnson County require property tax escrow accounts for borrowers with less than 20% down payment, though some lenders may require escrow regardless of down payment amount. Your lender collects monthly escrow payments along with your mortgage payment, typically 1/12th of the annual tax bill plus a small cushion. The escrow account pays your property taxes directly to the Johnson County Collector when bills are due.

Property taxes in Johnson County are due on May 10th and November 10th each year. If these dates fall on weekends or holidays, payment is due the next business day. Your lender typically pays these installments from your escrow account and provides an annual escrow analysis showing all deposits and payments. You should verify that payments are made on time, as you remain ultimately responsible for the taxes even when using escrow. If your tax bill changes significantly due to reassessment or exemption changes, your lender will adjust your monthly escrow payment accordingly.

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 Johnson County for the current fiscal year? A: Property taxes are due May 10th and November 10th annually. If these dates fall on weekends or holidays, payment is due the next business day.

Q: What tax credits are available and do I need to apply? A: The primary tax credit is the Homeowner Exemption, which reduces your equalized assessed value by up to $10,000 annually. This requires an application to be filed with the Johnson County Supervisor of Assessments office and is not automatic.

Q: How does the Homestead Exemption work? A: Illinois's Homestead Exemption (also called Homeowner Exemption) reduces your property's equalized assessed value by up to $10,000, not the market value. You must apply annually, and it only applies to your primary residence.

Q: Are there special exemptions for seniors or veterans? A: Yes, veterans with disabilities may qualify for additional exemptions under the Standard Homestead Exemption for Veterans with Disabilities. Senior citizens may qualify for the Senior Citizens Homestead Exemption. Both require separate applications with specific deadlines.

Q: When does the county reassess properties? A: Illinois law requires properties to be reassessed at least every four years. Johnson County follows the state's assessment cycle, with the Supervisor of Assessments determining the specific schedule for different areas.

Q: How do I appeal my property assessment? A: File an appeal with the Johnson County Board of Review during their designated hearing period, typically in summer. If unsatisfied, you can further appeal to the Illinois Property Tax Appeal Board (PTAB).

Q: What are the penalties for late payment? A: Late payments incur penalties and interest charges. The first installment penalty is typically 1.5% per month, while second installment penalties may be higher. Contact the Johnson County Collector for specific penalty rates.

Q: Can I pay my property taxes online? A: Contact the Johnson County Collector's office to inquire about online payment options, as availability varies by county in Illinois.

Q: Why did my taxes increase when property values in my area decreased? A: Property taxes depend on both assessed values and tax rates. Even if your property value decreases, taxes can increase if local government budgets (and therefore tax rates) increase, or if your property decreased less than the average in your taxing districts.

Q: What additional taxes might I see for special districts? A: Depending on your location, you may pay for fire protection districts, library districts, park districts, or other special purpose districts. The fire protection levy (FMLR) rate is 0.050000% where applicable.

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