The Longtime Homeowner Exemption in Cook County

What the exemption is

The Cook County Assessor describes the Longtime Homeowner Exemption as an expanded Homeowner Exemption with no maximum exemption amount. It comes in addition to the regular Homeowner Exemption, which reduces the equalized assessed value (EAV) of a home by $10,000.

It is rare. The Assessor says approximately 11,000 properties in Cook County qualify, fewer than 2% of homeowners, because the Illinois Property Tax Code sets strict eligibility requirements. If you want an overview of every exemption first, see Cook County property tax exemptions.

Who qualifies

For the current application, the Assessor lists three conditions:

• you owned and occupied the home from January 1, 2015, to January 1, 2025;
• your total household income was $100,000 or less for income tax year 2024;
• your property's assessment increase was large enough to exceed the maximum amounts set by the state legislature.

The third condition is the one most homes fail. The Assessor says most properties are not eligible because they have not seen a large enough increase in equalized assessed value for at least ten years. Living in the same home for a long time is not enough on its own.

The 7% or 10% test

The size of the increase you need depends on household income:

• household income of $75,000 or less: a 7% increase in equalized assessed value for each taxable year after the base year, through the current tax year;
• household income above $75,000 and up to $100,000: a 10% increase for each of those years.

Each year's increase is measured over the prior year, and the Assessor says it must occur for a period of ten years. Its FAQ adds that the increases do not have to occur in ten consecutive years.

Two terms help here. The base year is the tax year before the year you first qualify: if you first qualified in tax year 2014, your base year would be 2013. Equalized assessed value is your assessed value multiplied by the state equalizer.

How the application works

You do not start this one yourself in the usual way. The Assessor determines which properties qualify based on assessment increases and mails them an application. For tax year 2025, applications were mailed in April 2026 and were due Friday, May 15, 2026. The Assessor says applications received after May 15, 2026 will be processed as a Certificate of Error.

If you believe you qualify but did not receive an application, the Assessor asks you to call its office at 312-443-7550 so staff can double-check your qualifications, or to contact the office and request an application.

The exemption does not renew automatically: it must be filed every year. If you are eligible, the savings appear on the second installment tax bill issued later in the year. The Assessor also notes that under Illinois law, signing a fraudulent application is perjury, and anyone who receives the exemption is subject to audit.

Documents to include

The Assessor asks for a copy of a recent property tax bill and identification. The photo ID must come from its List A (an Illinois driver's license or ID card, a Matrícula Consular ID or a City of Chicago ID card). The name and property address must match the application, and the date of issue must show you occupied the property in calendar year 2025.

If the address on your photo ID does not match the property address, you provide one document from List B (photo ID that shows identity and date of birth, such as a passport), one from List C (proof of 2024 occupancy, such as a bank statement or a landline, cable or internet bill) and an Occupancy Affidavit. A notarized application is no longer required.

How it differs from the Senior Freeze

Both exemptions help owners whose values have risen, but they work differently:

• Who: the Senior Freeze is for homeowners over 65 (born in 1960 or earlier for the current application). The Longtime Homeowner Exemption has no age rule; it needs ten years in the home.
• Income: the Senior Freeze limit is a total household income of $65,000 or less for 2024. The Longtime limit is $100,000 or less.
• How it works: the Senior Freeze freezes the equalized assessed value of the home. It does not freeze the tax bill, because tax rates can change. The Longtime exemption is an expanded Homeowner Exemption with no maximum amount.
• Applying: seniors apply for the Senior Freeze every year during the spring filing period. For the Longtime exemption, the Assessor mails the application to the homes it finds eligible.

Both must be filed every year. For the two senior programs side by side, see Senior Exemption vs Senior Freeze.

Missed it? Certificates of Error

For the current year, the Assessor says Longtime applications received after May 15, 2026 are processed as a Certificate of Error, the process Illinois law provides for changing a tax bill that has already been issued. Certificate of Error applications can be denied.

The Assessor's page for missing exemptions in past tax years lists the Homeowner, Senior, Senior Freeze, Persons with Disabilities and veterans exemptions. If you think you missed the Longtime exemption in an earlier year, ask the Assessor's office directly. More on the process in Certificates of Error for a missed exemption.

Your next step

Check your latest second installment bill for the exemptions you already have. If you have lived in the home since at least 2015, your household income is within the limit and you did not receive an application, call the Assessor to check. An exemption and an appeal are separate: an exemption lowers the taxable value, while an appeal questions the assessed value itself. A free check of your home against similar homes shows whether your assessment also looks high.