The Illinois property tax rate averages about 1.83% of a home’s market value, the highest effective rate of any state in the country.1Tax Foundation. 2026 Illinois Tax Rates and Rankings That statewide figure hides a lot. What you actually pay depends on the county you live in, how your assessor values your home, the state multiplier applied to your county, the mix of school, municipal, and special districts that overlap your parcel, and which exemptions you have on file. Two homes a mile apart can end up with meaningfully different bills.
Illinois leans so heavily on property taxes because it funds schools, fire protection, libraries, and most other local services this way rather than through state revenue. The rate on your bill is not set in Springfield. It is built up locally, one taxing district at a time.
How Your Assessed Value Is Set
Every bill starts with the county or township assessor. Outside Cook County, the assessor determines fair cash value and then applies the statutory assessment level of 33⅓% of that value.2Illinois General Assembly. Illinois Compiled Statutes 35 ILCS 200/9-145 – Statutory Level of Assessment A home worth $300,000 carries an assessed value of $100,000.
Cook County does it differently. Property there is classified by use. Single-family homes and other residential property are assessed at 10% of market value; most commercial property is assessed at 25%.3Cook County Assessor. Glossary That same $300,000 home in Cook County starts with an assessed value of just $30,000, before the state equalization factor pushes it back up.
The State Equalization Factor and EAV
Because 102 county assessors don’t value property identically, the Illinois Department of Revenue applies an equalization factor, often called the multiplier, to each county. The department compares actual sale prices to assessed values over a three-year period. Counties running below the one-third requirement get a multiplier above 1.0 that lifts assessments up; counties running high get pulled down.4Illinois Department of Revenue. Cook County Final Multiplier for 2024 Because Cook County assesses residential property at 10% rather than 33⅓%, its multiplier tends to run much higher than other counties to compensate.
The assessed value multiplied by the equalization factor gives you Equalized Assessed Value, or EAV. This is the number that drives your bill. Exemptions come off EAV. Tax rates get applied to EAV. When someone asks what your property tax rate works out to in dollars, the math runs through EAV, not market value.
How Local Tax Rates Are Built
There is no single Illinois property tax rate because the rate on your bill is the sum of several separate rates. School districts, park districts, library boards, fire protection districts, municipalities, community colleges, and other local bodies each submit an annual budget request called a levy. The county clerk divides each district’s levy by the total EAV of all taxable property within that district to produce the rate for that district.5Illinois General Assembly. Illinois Compiled Statutes 35 ILCS 200 – Property Tax Code
A typical Illinois homeowner sits inside six to ten overlapping districts at once. Each district calculates its rate independently, and those rates add together to form the aggregate rate printed on your bill. Multiply that aggregate rate by your EAV after exemptions, and you have your tax. Because different neighborhoods fall under different combinations of districts, your neighbors across a district boundary may pay a visibly different rate on an identical home.
What PTELL Does to Rate Increases
The Property Tax Extension Limitation Law, usually called PTELL or simply “tax caps,” is the main constraint on growth. Most non-home-rule taxing districts cannot increase their total levy by more than 5% or the percentage change in the Consumer Price Index, whichever is less.6Illinois General Assembly. Illinois Compiled Statutes 35 ILCS 200/18-185 – Property Tax Extension Limitation Law In low-inflation years that can hold growth well below 5%.
PTELL originally covered only Cook County and the collar counties, but it has since been extended to non-home-rule districts across the state. One detail catches homeowners off guard: PTELL caps the total dollar amount a district can collect, not your individual bill. New construction added to the tax base lets a district collect more than the cap would otherwise allow. And if your home’s EAV goes up faster than average in your district, your share of a capped total still grows. The ceiling is on the levy, not on you.
Why Rates Vary So Much Across the State
The gap between the highest-taxed and lowest-taxed counties is wide. In recent years, the average annual property tax bill in Lake County topped $8,600, while in Pulaski County at the state’s southern tip it ran below $700. Those numbers reflect very different property values, very different numbers of taxing districts, and very different local budget demands rather than one uniform rate applied unevenly.
Communities with high property values can fund their services at a lower nominal rate because the base is large. Communities with lower property values have to charge a higher rate to raise the same revenue for comparable services. Cook County’s classification system shifts some of the load off residential owners and onto commercial property, but the higher multiplier the state applies to Cook County claws some of that difference back.
The 1.83% statewide average is a middle point in a wide distribution.1Tax Foundation. 2026 Illinois Tax Rates and Rankings Your real effective rate could land well above or well below it depending on where in the state you own.
Exemptions That Lower What You Pay
Exemptions reduce your EAV before the rate is applied, which is why they matter even when you cannot do anything about the rate itself. None of these are automatic. Each requires an application to your county assessor, and missing a filing generally means paying more than you owe without a retroactive fix.
General Homestead Exemption
Any owner-occupied principal residence qualifies. The maximum EAV reduction is $10,000 in Cook County, $8,000 in the collar counties, and $6,000 elsewhere in the state.7Illinois General Assembly. Illinois Compiled Statutes 35 ILCS 200/15-175 – General Homestead Exemption Most long-time owners receive the full maximum because the exemption is calculated against appreciation above a 1977 base value, and decades of growth easily hit the cap.
Senior Citizens Homestead Exemption
Homeowners 65 or older who occupy the home as their principal residence receive an additional EAV reduction of up to $8,000 in Cook County and the collar counties, or $5,000 elsewhere.8Illinois General Assembly. Illinois Compiled Statutes 35 ILCS 200/15-170 – Senior Citizens Homestead Exemption It stacks on the general homestead exemption, so a qualifying senior in Cook County can see up to $18,000 in combined EAV reduction.
Senior Citizens Assessment Freeze
Separately, the Low-Income Senior Citizens Assessment Freeze locks your EAV at the level it was when you first qualified. Your EAV will not rise while you continue to qualify, though your bill can still move if rates do. For the 2026 tax year, total household income must be $75,000 or less.9Illinois Department of Revenue. Property Tax Relief – Homestead Exemptions, PTELL, and Senior Citizens Real Estate Tax Deferral Program The threshold rises to $77,000 for 2027 and $79,000 for 2028 and later. Reapplication is required every year.
Persons with Disabilities Homestead Exemption
Homeowners with a disability occupying the home as a primary residence receive a $2,000 annual EAV reduction, with documentation filed annually at the county assessor’s office.9Illinois Department of Revenue. Property Tax Relief – Homestead Exemptions, PTELL, and Senior Citizens Real Estate Tax Deferral Program
Disabled Veterans Homestead Exemption
Veterans with a service-connected disability certified by the U.S. Department of Veterans Affairs receive an EAV reduction tied to the disability rating:10Illinois General Assembly. Illinois Compiled Statutes 35 ILCS 200/15-169 – Standard Homestead Exemption for Veterans With Disabilities
- 30% to 49% disability: $2,500 EAV reduction
- 50% to 69% disability: $5,000 EAV reduction
- 70% or higher disability: the first $250,000 of EAV is exempt from taxation
- Surviving spouses receiving VA dependency and indemnity compensation also qualify for the $250,000 exemption
World War II veterans are exempt from property tax entirely regardless of disability level, for tax years from 2024 onward.10Illinois General Assembly. Illinois Compiled Statutes 35 ILCS 200/15-169 – Standard Homestead Exemption for Veterans With Disabilities
Appealing an Over-Assessment
If your property is valued too high, an appeal is the most powerful lever you have on your bill. Exemptions subtract fixed amounts; a successful appeal cuts the underlying EAV, and the correction keeps saving you money every year it holds.
Outside Cook County, the first step is a written complaint to your county’s Board of Review, which can correct any assessment that appears unjust.11DuPage County. Board of Review Strong appeals bring recent comparable sales, an independent appraisal, or evidence of defects the assessor missed. Filing deadlines are set county by county and printed on your assessment notice; the window is often only 30 days, so read the notice when it arrives.
Cook County runs on a separate track. When your township opens for reassessment you can file first with the Cook County Assessor’s Office during the published window, then appeal again to the Cook County Board of Review after the Assessor rules.12Cook County Assessor’s Office. Assessment and Appeal Calendar An appeal window is also available in years when your township is not up for reassessment.
If the Board of Review denies your appeal or grants less relief than you believe is warranted, you have 30 days from the decision notice to escalate to the Illinois Property Tax Appeal Board.11DuPage County. Board of Review PTAB conducts an independent review and can order a different assessed value. The process is more formal than the county board, but homeowners can represent themselves.
When Taxes Are Due and What Happens If You’re Late
Illinois property taxes are paid in arrears, so the bill you pay this year covers last year’s assessment. In most counties, bills go out in the spring with a first installment due around June and a second around September. Dates vary by county.
Cook County runs on its own calendar. The first installment is due in March and equals 55% of the prior year’s total tax.13Cook County Assessor’s Office. How Are My Taxes Calculated? The second installment, which reflects the current year’s assessment and any rate changes, is due in August.14Cook County Assessor’s Office. Your Assessment Notice and Tax Bill
Miss a due date and interest accrues at 1.5% per month, or any partial month, on the unpaid balance.15Illinois General Assembly. Illinois Compiled Statutes 35 ILCS 200/21-15 – Interest Penalties That annualizes to 18%, among the most expensive debt a homeowner can carry. If the delinquency continues, the county treasurer sells the taxes at an annual tax sale, and the winning bidder receives a tax lien.16Illinois General Assembly. Illinois Compiled Statutes 35 ILCS 200 – Tax Sale Procedures You then have a statutory redemption period to pay everything owed and clear the lien: two and a half years for residential property with fewer than six units, or one year for vacant non-farm land, commercial or industrial property, and buildings with seven or more residential units.17Illinois General Assembly. Illinois Compiled Statutes 35 ILCS 200/22-5 – Redemption Periods Fail to redeem and the lienholder can petition for a tax deed, and the property is lost.