Illinois Property Tax 2026: PTELL, Senior Freeze and Cook County Appeal Schedule

Illinois has the second-highest effective property tax rate in the country, the most complicated assessment system of any state, and a set of senior exemptions that most eligible homeowners never claim. This 2026 guide covers the 33.33% equalized assessment standard (10% in Cook County), the PTELL extension cap that holds local tax districts to 2.9% revenue growth for 2026, the expanded Senior Freeze threshold, and the rolling township-by-township appeal calendar that has no single statewide deadline.

How Illinois Property Tax Works

Illinois uses a three-step calculation that layers local assessment, county equalization, and the Property Tax Extension Limitation Law (PTELL).

Step 1: Township or county assessment

Local assessors (township assessors outside Cook County, the Cook County Assessor's Office in Cook) establish fair cash value and apply the state-mandated assessment ratio. In most of Illinois this is 33.33 percent of fair cash value. In Cook County, residential property (1-6 unit buildings, condos, vacant residential land, apartment buildings) is assessed at 10 percent; commercial and industrial at 25 percent.

Step 2: State equalization ("multipliers")

The Illinois Department of Revenue issues an equalization factor ("multiplier") annually for each county to bring the overall assessment level to 33.33 percent of fair cash value. For counties that assess too low, the multiplier is greater than 1.0; for counties that assess too high, less than 1.0.

Step 3: Local tax rates + PTELL cap

Each taxing district (county, township, school district, park district, library, etc.) adopts a tax levy, subject to statutory maximums. PTELL then limits the total revenue increase for non-home-rule districts to the lesser of 5 percent or the rate of inflation. For the 2026 tax year (payable in 2027), the Illinois Department of Revenue set the PTELL inflation factor at 2.9 percent.

The Illinois Exemption Stack — What Every Homeowner Should Claim

General Homestead Exemption (GHE)

Reduces equalized assessed value (EAV) by up to $6,000 for Illinois residents who own and occupy the property as their principal residence. In Cook County, the reduction is $10,000 of EAV. Automatic on most parcels but can lapse when ownership changes — verify on your tax bill.

Senior Citizen Homestead Exemption

An additional $5,000 EAV reduction for homeowners age 65 or older who occupy the home as their principal residence. Apply with the county assessor; in Cook County the application renews automatically once filed.

Senior Freeze Exemption (Senior Citizens Assessment Freeze Homestead Exemption)

For homeowners age 65+ with total household income below the statutory threshold, the Senior Freeze fixes the EAV at the base-year level — future reassessments do not raise the taxable base. The household income limit is:

• Tax year 2025 (payable 2026): $65,000
• Tax year 2026 (payable 2027): $75,000 (raised by recent legislation)

The Senior Freeze is the single highest-value senior exemption in Illinois. In a rising-value market, the tax savings compound dramatically. Apply annually; Cook County applications for tax year 2025 open March 9, 2026.

Homestead Exemption for Persons with Disabilities

Reduces EAV by $2,000 for homeowners determined to have a qualifying disability under federal standards.

Veterans with Disabilities Exemption

Sliding scale based on VA service-connected disability rating:

• 30% to 49% disability: $2,500 EAV reduction
• 50% to 69% disability: $5,000 EAV reduction
• 70%+ disability or 100% total and permanent: full property tax exemption on the primary residence

Returning Veterans Homestead Exemption

$5,000 EAV reduction for the tax year in which a qualifying veteran returns from active duty in an armed conflict involving U.S. armed forces.

Long-Time Occupant Homestead Exemption (Cook County only)

Automatic cap on the growth of EAV for homeowners who have lived in the home for 10+ years, with income limits that vary annually.

PTELL: What It Does and Doesn't Cap

The Property Tax Extension Limitation Law (PTELL) limits how fast taxing districts can extend (collect) property tax revenue. It does not cap:

• Individual tax bills (your bill can rise substantially if your EAV grew faster than the district average)
• Individual assessed values
• Home-rule municipalities (Chicago, most large Illinois cities) — which are exempt from PTELL

What PTELL does

For covered taxing districts, the aggregate property tax extension can grow year-over-year by only the inflation factor (2.9% for 2026) plus an adjustment for new construction and annexations. Voters may approve additional levies at referendum.

Practical effect on homeowners

If your county's total assessed value grew 8 percent but PTELL limits the extension to 2.9 percent, the effective tax rate is rolled back so the total revenue stays within the cap. Individual homeowners whose property value grew faster than the county average pay more; those whose property grew slower pay less. PTELL cuts the aggregate, not individual bills.

Appealing Your Assessment

Appeal deadlines and processes differ dramatically between Cook County and the other 101 counties.

Cook County — rolling township schedule

Cook County does not have a single statewide deadline. Instead, the Cook County Assessor publishes a rolling schedule where 4 to 5 townships open for appeals each month, with each township's filing window lasting approximately 30 days. Watch the Cook County Assessor's Assessment Calendar and Deadlines page for your township's window.

After the Assessor's Office, you may appeal to the Cook County Board of Review (separate windows by township, typically opening after the Assessor's window closes). Beyond the Board of Review, appeals go to the Illinois Property Tax Appeal Board (PTAB) or Cook County Circuit Court.

Other Illinois counties — 30-day window

Most non-Cook counties open a 30-day appeal window after the assessor publishes the annual list of changes. Dates are posted in local newspapers and on county websites. File with the county Board of Review (Supervisor of Assessments in some counties). Decisions may be appealed to PTAB within 30 days.

Senior Freeze and appeals

Homeowners on the Senior Freeze Exemption cannot appeal their assessment while the freeze is in place — the EAV is frozen at the base year. If you need to contest the base-year value, you must appeal before the freeze is established.

Cook County in 2026: Kaegi Reassessments and CLR

Cook County's 2026 reassessment cycle covers the City of Chicago (Chicago is reassessed every third year; suburban Cook is split into north and south triads in the other two years). Assessor Fritz Kaegi's reassessment methodology has emphasized market-value-based residential assessments.

Residential impact

2026 Chicago residential reassessments showed significant variation by neighborhood, with some gentrifying areas up 20 to 40 percent and others flat or down. The county's median EAV was up modestly statewide.

Commercial impact

The Kaegi administration has raised commercial and industrial assessments significantly, shifting more of the tax burden from residential to commercial. This has resulted in contentious Board of Review reductions and ongoing litigation.

Cook County exemption renewal (2026)

For tax year 2026, the Cook County Assessor is continuing the automatic renewal system for most senior exemptions, eliminating the annual reapplication requirement for many homeowners. Check your 2026 property tax bill to confirm each exemption is applied — errors are common in a system of this size.

Payment Schedule

Illinois property tax is paid a year in arrears — your 2026 tax bill covers the 2025 tax year. Most counties issue bills in two installments:

• First installment: typically due May or June (in Cook County, March 1 as a statutory first installment equal to 55% of prior year)
• Second installment: typically due September, October or November (Cook County varies depending on reassessment delays)

Delinquency accrues 1.5 percent per month interest. Extended delinquency can result in the county tax sale, where unpaid taxes are purchased by tax-lien buyers; the homeowner then has a redemption period (typically 2.5 to 3 years) to repay with interest before the tax buyer can take title.

Frequently Asked Questions

What is the property tax rate in Illinois for 2026?

Illinois has no statewide property tax rate; rates are set at the local level. The statewide median effective rate is approximately 2.08 percent of market value — the second highest in the United States behind New Jersey. Cook County (Chicago) averages 2.04 percent, DuPage County 2.07 percent, Kane County 2.30 percent, with substantial variation by municipality and school district.

How do I qualify for the Illinois Senior Freeze Exemption?

Homeowners age 65 or older who own and occupy the home as their principal residence, with total household income below the statutory threshold ($65,000 for tax year 2025, $75,000 for tax year 2026). The exemption freezes the equalized assessed value at the base-year level. Apply annually with your county assessor — Cook County 2025 applications open March 9, 2026.

When is the Cook County property tax appeal deadline?

Cook County uses a rolling township-by-township calendar with no single deadline. Each township has a filing window of approximately 30 days; 4-5 townships open each month throughout the year. Check the Cook County Assessor's Assessment Calendar and Deadlines page for your specific township. After the Assessor's Office window closes, the Cook County Board of Review opens a separate appeal window.

What is PTELL in Illinois?

The Property Tax Extension Limitation Law caps the year-over-year growth of total property tax revenue for non-home-rule taxing districts at the lesser of 5 percent or the rate of inflation (2.9 percent for 2026). PTELL does not cap individual tax bills or assessments — only aggregate district revenue growth. Home-rule cities including Chicago are exempt from PTELL.

How does the 100% Disabled Veterans exemption work in Illinois?

Veterans with a 100 percent service-connected disability rating (or their surviving spouses) receive a full exemption from property tax on their primary residence. Veterans with 70-99% disability qualify for the same full exemption. Lower disability ratings produce smaller EAV reductions on a sliding scale ($2,500 for 30-49%, $5,000 for 50-69%). Apply with your county assessor providing VA disability documentation.