Cook Property Tax: Deadlines, Exemptions & Appeals (2026)

As of July 30, 2026, the next Cook County Assessor residential appeal deadline is July 31, 2026 for Cicero Township; other currently posted upcoming Assessor deadlines include Elk Grove: August 4, Stickney: August 12, and West Chicago: August 21. File first with the Cook County Assessor’s Office (CCAO) through SmartFile, or—if you cannot use the portal—by email, mail, or in person; the Cook County Board of Review (BOR) is a separate, later appeal forum that opens each township after the Assessor’s work is completed. (rpie.cookcountyassessor.com)

How assessments work in Cook

Cook County is not on one countywide appeal deadline. The county is divided into townships and a three-region triennial reassessment cycle. In 2026, the south and west suburbs are the scheduled reassessment area; the north suburbs and the City of Chicago are generally not reassessed in 2026 unless a property has a special change such as division work, permits, or other circumstances. (rpie.cookcountyassessor.com)

For a typical homeowner, the Assessor estimates the home’s fair market value from property characteristics and sales patterns for similar homes. Class 2 residential property—single-family homes, townhomes, condos, co-ops, and residential/mixed-use buildings of six units or fewer—is assessed at 10% of estimated market value. That assessed value is then multiplied by the state equalization factor to get EAV, exemptions are subtracted, and your local tax rate is applied. The Assessor sets value, not tax levies, rates, or bills. (rpie.cookcountyassessor.com)

For recent actual tax-bill math, use your own second-installment bill because rates vary widely by tax code. One official Treasurer example for Maywood tax code 31132 shows a 2024 total tax rate of 15.3858% and total 2024 tax of $9,340.73 for PIN 15-14-135-011-0000; that is an example rate, not a countywide average. (cookcountytreasurer.com)

Whether you should appeal

Appeal if the notice overstates what your home would sell for, lists the wrong square footage/class/condition, or makes your property look assessed higher than genuinely similar homes in the same assessment neighborhood. The CCAO’s own rule of thumb is practical: if the characteristics are correct and the estimated market value is within about 10% of what you think the home is worth, an appeal may not change the bill enough to matter. (rpie.cookcountyassessor.com)

Good Cook-specific evidence includes: a recent arm’s-length closing statement showing you bought for less than the Assessor’s market value; comparable homes in the same neighborhood code and class with lower assessments per square foot; photos and permits showing damage, vacancy, demolition, or condition problems; and a survey or appraisal if the county’s square footage is wrong. For CCAO residential uniformity appeals, you are not required to find your own comps—the analysts can review comparable properties—but strong, close comps can help. (rpie.cookcountyassessor.com)

Published BOR data is encouraging but not a promise. The Board’s FY 2025 / Tax Year 2024 annual report says the percentage of residential appellants receiving a reduction remained over 50%, and that over 58% of residential pro se appellants received a property assessment decrease in Tax Year 2024. (cookcountyboardofreview.com)

Step-by-step how to file

1. Find your PIN and township. Your 14-digit PIN is on Assessor and Treasurer mailings; the county portal and BOR homepage also let you search by address. Do not use a Chicago neighborhood name as your deadline—Cook deadlines are by township. (cookcountypropertyinfo.com)

2. Check the live deadline. CCAO Rule 10 says the appeal and all supporting documents must be filed by the official township closing date; the CCAO calls these “hard” deadlines. As of July 30, 2026, Cicero closes July 31, Elk Grove August 4, Stickney August 12, and West Chicago August 21. (rpie.cookcountyassessor.com)

3. File with the Cook County Assessor first. The relevant homeowner form is the Residential Appeal Form / Real Estate Assessed Valuation Appeal; supporting forms may include Residential Appeal Narrative, Attorney Representative Authorization, Documents in Support of Appeal and/or Certificate of Error Form A/B, and Field Check Request Letter. CCAO strongly prefers online filing through SmartFile. If online filing is not possible, a pro se owner may email appeal documents to assessor.onlineappeals@cookcountyil.gov with “Assessment Appeal,” the township, and lead PIN in the subject line; file in person at 118 N. Clark St., Room 320, Chicago, IL 60602; or mail the paper form to that same address. Filing is free. (rpie.cookcountyassessor.com)

4. Then consider the Board of Review. After the Assessor’s period, you get another county-level appeal at the Cook County Board of Review, a separate quasi-judicial agency independent of the Assessor. Use the Board of Review Complaint Form; attorneys use the Attorney Authorization Form 2026 Session when applicable. BOR complaints may be filed online through the BOR Appeals Portal, delivered or mailed as an original complaint, or filed in person at 118 N. Clark St., Room 601, Chicago, IL 60602. BOR Rule 8 allows online filing; otherwise complaints are filed at the Board office, and a U.S. Postal Service postmark is treated as the filing date, though the Board says it is not responsible for mailed complaints. BOR filing is free. (cookcountyboardofreview.com)

What happens after

At the CCAO level, expect a document review, not a courtroom-style hearing. If you filed in person you receive an appeal number; if you filed by mail, a receipt letter is returned. The Assessor’s Office analyzes the appeal and notifies you of results by letter. If you still disagree, you may go to the BOR for the same tax year when your township opens. (prodassets.cookcountyassessor.com)

At the BOR, a homeowner may request a hearing when filing, but a hearing is not required. Residential hearings are generally telephonic; attorneys use Microsoft Teams. The Board says analysts use the same analytical process for files with hearings and files without hearings, so request a hearing mainly when written evidence cannot explain a unique condition. If you request one, the Board notifies you of the date and time, and evidence may be submitted through the portal or clerk’s office up to five days before the hearing. (cookcountyboardofreview.com)

A BOR decision sets the final county valuation for that tax year. The second-installment bill cannot be calculated until the BOR finishes reviewing appeals for all 38 townships. After a BOR decision, further appeal options include the Illinois Property Tax Appeal Board or Cook County Circuit Court. (cookcountyboardofreview.com)

Local tips

Check exemptions before spending money on an appeal. The Homeowner Exemption reduces EAV by $10,000 and generally auto-renews. The Senior Exemption reduces EAV by $8,000 and auto-renews for eligible homeowners age 65 or older. The Low-Income Senior Freeze is for seniors with household income of $65,000 or less for the relevant income year; it freezes EAV, not the tax bill, and tax rates can still change. Cook also has exemptions for persons with disabilities, returning veterans, veterans with disabilities, long-time homeowners, and home improvements. (rpie.cookcountyassessor.com)

A realistic savings example: suppose a Maywood homeowner in tax code 31132 persuades the Assessor or BOR that a $350,000 market value should be $325,000. The $25,000 market reduction becomes a $2,500 assessed-value reduction at Cook’s 10% residential level. Using the 2024 Cook multiplier of 3.0355, that is $7,588.75 less EAV. At the actual 2024 Maywood example rate of 15.3858%, the rough annual tax savings would be about $1,167 before any interaction with exemptions or levy changes. Your result may be much lower in a lower-rate tax code, so always run the same formula with your own bill. (content.govdelivery.com)

When Are Property Taxes Due in Cook?

Tax Year 2025 First Installment Property Tax Due Date: Wednesday, April 1, 2026. The Treasurer's current official due-date page does not list a Tax Year 2025 Second Installment due date. Cook County bills property taxes in installments; the current officially posted due-date page confirms the Tax Year 2025 First Installment due date only.

This is not the same as the assessment appeal deadline above. The appeal deadline is your window to contest your assessed value; the payment due date is when the resulting tax bill must be paid. Missing one does not affect the other, but missing either has real consequences — one forfeits your right to appeal for the year, the other can trigger penalties and interest.

Source: https://www.cookcountytreasurer.com/duedates.aspx

Property Tax Exemptions in Cook

• Homeowner Exemption — Owners who occupy the property as their principal place of residence on January 1 of the tax year.. Reduces Equalized Assessed Value (EAV) by $10,000; the tax-bill savings depends on the property's local tax rate. Yes for new applicants; once applied, it auto-renews each year. Apply by Applications received after May 15, 2026 are processed as a Certificate of Error for the current tax year.. (Source: https://www.cookcountyassessoril.gov/homeowner-exemption)
• Senior Exemption — Homeowners age 65 or older who own and occupy the property as their principal place of residence.. Reduces Equalized Assessed Value (EAV) by $8,000; the tax-bill savings depends on the property's local tax rate. Yes, one-time application; it automatically renews after approval. Apply by Applications received after May 15, 2026 are processed as a Certificate of Error for the current tax year.. (Source: https://www.cookcountyassessoril.gov/senior-citizen-exemption)
• Low-Income Senior Assessment Freeze Exemption (Senior Freeze) — Senior homeowners who meet the Senior Exemption requirements and, for the 2025 tax year application, had total adjusted gross household income of no more than $65,000 for calendar year 2024.. Freezes the home's Equalized Assessed Value (EAV); it does not freeze the total tax bill because tax rates can change. Yes, renew annually. Apply by Applications received after May 15, 2026 are processed as a Certificate of Error for the current tax year.. (Source: https://www.cookcountyassessoril.gov/senior-freeze-exemption)
• Persons with Disabilities Exemption — Homeowners who are disabled or became disabled during the 2025 tax year and meet documentation and occupancy requirements.. Annual $2,000 reduction in Equalized Assessed Value (EAV). Yes for new applicants; automatically renews going forward for those who received it last year under new state legislation. Apply by Applications received after May 15, 2026 are processed as a Certificate of Error for the current tax year.. (Source: https://www.cookcountyassessoril.gov/persons-disabilities-exemption)
• Returning Veterans Exemption — Illinois resident veterans returning from active duty in an armed conflict involving the U.S. armed forces in the tax year, who own or have a legal/equitable interest in the property, use it as a principal residence, and are liable for property taxes.. $5,000 reduction in Equalized Assessed Value (EAV) for each taxable year in which the veteran returns. Yes, renew/apply annually for each eligible year. Apply by Applications received after May 15, 2026 are processed as a Certificate of Error for the current tax year.. (Source: https://www.cookcountyassessoril.gov/returning-veterans-exemption)
• Veterans with Disabilities Exemption — Veterans with at least a 30% service-connected disability certified by the U.S. Department of Veterans Affairs who own and occupy the property as their primary residence; certain non-remarried surviving spouses may also qualify.. EAV reduction depends on VA disability rating: 30–49% = $2,500; 50–69% = $5,000; 70% or greater = $250,000, which can fully exempt the home from property taxes. Yes, generally annually; veterans rated 100% disabled and classified as permanently and totally disabled by the VA automatically renew under new legislation. Apply by Applications received after May 15, 2026 are processed as a Certificate of Error for the current tax year.. (Source: https://www.cookcountyassessoril.gov/veterans-disabilities-exemption)

How to Look Up Your Property Record in Cook

You can look up your property's official record at https://www.cookcountypropertyinfo.com/Pages/Payment-Search.aspx. The official Cook County Property Tax Portal lets owners search by PIN or address and shows billed amounts and tax history, property description, township, tax rate and tax code, classification, estimated property value, assessed value, exemptions, refunds, and related document/deed/lien information.