Cook County's Longtime Homeowner Exemption limits how fast a long-time owner's taxed value can grow: 7% a year for household incomes of $75,000 or less, and 10% a year up to $100,000. The Assessor's page says about 11,000 homes qualified, fewer than 2% of homeowners.
Qualifying is not the same as saving more. State law gives you whichever is larger: the regular $10,000 homeowner exemption, or the amount your value has grown past the capped line. In tax year 2024, 593 homes got more than the regular $10,000 from it, a median of about $1,663 extra for the year.
That is why timing matters. A reassessment is when values jump past the line. The south and west suburbs were reassessed for tax year 2026, and Chicago is next, for tax year 2027.
Quick Answer
The Longtime Homeowner Exemption is for Cook County owners who have lived in the same home for at least 10 years in a row (5 years if a government or nonprofit housing program helped them buy it) and have household income of $100,000 or less. It limits growth in the home's taxed value to 7% a year for household incomes of $75,000 or less, or 10% a year for incomes from $75,001 to $100,000, counted from a base year. It replaces the regular homeowner exemption and is never worth less than it, but it only adds savings in years when your value has grown more than $10,000 past the capped line. You cannot have it and the Senior Freeze at the same time. It is not automatic: each spring the Assessor mails an application to the homes it calculates may qualify, and you have to return it by the date printed on it.
Who qualifies
The Assessor's page and the state law set four tests.
- Ten years in the same home. You must have lived there as your main home for at least 10 years in a row as of January 1 of the tax year. For tax year 2025, the Assessor's test was owning and living in the home from January 1, 2015, through January 1, 2025.
- Five years if you had help buying. The law shortens this to 5 years if you bought the home with help from a government or nonprofit housing program.
- Household income of $100,000 or less. The Assessor checks the calendar year before the tax year. For tax year 2025, that was 2024 income. "Household income" uses the same definition as the Senior Freeze.
- A big enough rise in value. The Assessor says the home's assessment increase must exceed the yearly limits written into state law. This is the test most long-time owners fail.
The income limits are fixed dollar amounts in state law, not adjusted for inflation, and there is no test tied to local median income. The Assessor's page has listed the same $100,000 cap since at least 2020. The one recent change is on the Assessor's side: the application no longer has to be notarized. State law offers the exemption only in counties that opted into an alternative homestead system, and the Assessor runs it in Cook.
How the cap works, with arithmetic
The exemption looks at the home's equalized assessed value (EAV), the number your tax rate is applied to.
- It sets a starting point in the base year, which is the tax year before you first qualify. The starting point is that year's EAV minus the regular $10,000 homeowner exemption.
- It lets that starting point grow 7% or 10% a year, compounding, depending on your income.
- Everything above that line is exempt. If the line works out to less than $10,000 of savings, you get the regular $10,000 instead.
An illustrative example. A home's EAV was $30,000 in the base year, so the starting point is $20,000. Ten years later, at 7% a year, the line has grown to $39,343. The tax rate is 8.5%, close to the median rate on Cook County homes with the homeowner exemption in tax year 2024 (8.52%).
| Today's EAV | Income tier | Longtime exemption | Regular exemption | Extra EAV exempt | Extra savings at 8.5% |
|---|---|---|---|---|---|
| $60,000 | 7% cap | $20,657 | $10,000 | $10,657 | about $906 a year |
| $45,000 | 7% cap | $10,000 | $10,000 | $0 | $0 |
| $60,000 | 10% cap | $10,000 | $10,000 | $0 | $0 |
In the second row, the value grew, but not faster than 7% a year. In the third row, the 10% line has reached $51,875, so the same $60,000 home gets nothing extra. That is why so few qualifying homes save more than the regular $10,000. Two more rules: if the EAV ever falls below the starting point, the starting point resets lower, and an addition raises it.
What the record shows
Homes that got more than the regular $10,000 from the Longtime exemption, from the county's bill records:
| Tax year | Homes | In Chicago | Median extra savings |
|---|---|---|---|
| 2021 | 713 | 703 | $1,571 |
| 2022 | 840 | 818 | $1,436 |
| 2023 | 582 | 581 | $1,698 |
| 2024 | 593 | 522 | $1,663 |
In tax year 2024, a quarter of these homes saved less than $705 extra and a quarter saved more than $3,091. Most were in Chicago: 522 of 593 in tax year 2024, and all but one in 2023.
The Assessor's page puts the number of qualifying homes at about 11,000. Both numbers can be right. A qualifying home whose value has not grown more than $10,000 past its capped line gets the same $10,000 it would get anyway, and nothing extra. The extra shows up only after a big jump in value, which is why reassessment years matter.
How it fits with your other exemptions
- Regular homeowner exemption: the Longtime exemption replaces it. You never get less than the $10,000 it would have given you.
- Senior exemption: you can have both. In tax year 2024, 249 of the 593 homes also had the senior exemption.
- Senior Freeze: the law does not allow both. The Freeze holds the value at its base year. The Longtime cap lets it grow 7% or 10% a year.
- Selling or passing on the home: if the home goes to a spouse, or between a parent and child, the exemption stays if the new owner's household income is $100,000 or less. After any other sale, it stays for the rest of that tax year.
Applying, and why reassessment years matter
The Assessor decides which homes may qualify from their assessment history and mails those owners an application. For tax year 2025, whose bills are paid in 2026, applications went out in April 2026 and were due May 15, 2026. Expect the same rhythm each year: a spring mailing for the tax year before.
The application asks for a recent tax bill and a photo ID showing the property address; other documents work if your ID shows a different address. It is signed under penalty of perjury, and recipients can be audited. Savings show up on the second-installment bill. If you think you qualify and no application arrived, call the Assessor at 312-443-7550.
A reassessment is when values are most likely to outrun the line. If your 2026 notice in the south or west suburbs, or your 2027 notice in Chicago, shows a steep jump and your household income is $100,000 or less, watch the mail the following spring. The exemption does not change the Assessor's value, so if the value is wrong, appeal it too. Our guides to the 2026 south and west reassessment and Chicago's 2027 reassessment cover the notices.
Where Censum fits
Censum's free exemption check shows which exemptions are on your home's record: homeowner, senior, Senior Freeze, veteran and disability. It does not decide Longtime eligibility; the Assessor does that from its own records. If the check finds an exemption you missed in past years, Censum can prepare the Assessor's refund filing. County exemption forms are free.
The numbers behind this article
Counts and savings are Censum's tabulation of PIN-level exemption amounts in PTAXSIM, the Cook County Assessor's Office research database built from Clerk and Treasurer records, tax years 2021 through 2024; the Assessor describes its results as not official. A home counts when its Longtime amount is above zero. For 2021 through 2023 the record lists the full Longtime amount, so the extra is that amount minus $10,000; for 2024 it lists the regular $10,000 plus a separate Longtime amount, which is the extra. Savings are the extra EAV times the home's total tax-code rate that year. "In Chicago" means the city's eight assessment townships. The 1,005,437 homeowner exemptions and the 8.52% median rate (tax year 2024) are from the same database. The 11,000 figure and the tax year 2025 dates are from the Assessor's page, which has shown the same 11,000 figure since at least 2020. The rule that the exemption is the larger of the regular $10,000 or the growth past the capped line is in the state law (35 ILCS 200/15-177(d)). The worked example is illustrative and follows the formula in state law.
FAQ
Do I have to apply every year?
Yes. The exemption does not renew on its own. Each spring the Assessor mails an application to the homes it calculates may qualify, and you return it by the date printed on it.
Can I have it with the Senior Freeze or the senior exemption?
Not with the Senior Freeze; state law allows one or the other. With the senior exemption, yes.
I have lived here 20 years and my assessment went up a lot. Why don't I qualify?
The Assessor says most homes fail because their value has not grown faster than the 7% or 10% yearly line over the years. Income over $100,000 also rules a home out.
The Assessor says about 11,000 homes qualify. Why did only 593 save extra in 2024?
Because the exemption pays whichever is larger: the regular $10,000, or the growth in value past the capped line. Most qualifying homes had not grown far enough past the line, so they got the regular $10,000 and nothing more.
Does it lower my assessment?
No. It removes part of the taxed value before the bill is figured. The Assessor's value stays the same, and you can still appeal it.
Sources
- Cook County Assessor, Longtime Homeowner Exemption
- Cook County Assessor, Property Tax Exemptions
- Cook County Assessor, Senior Freeze Exemption
- Cook County Assessor, The Cook County Property Tax System (reassessment years)
- Illinois Property Tax Code, 35 ILCS 200/15-177 (long-time occupant homestead exemption)
- Censum tabulation of PIN-level exemption amounts and tax code rates, tax years 2021-2024, from PTAXSIM (Cook County Assessor's Office), run November 11, 2026.
Sources accessed November 11, 2026.
Next step
See which exemptions are on your home's record before the next notice arrives. Check my exemptions
Censum LLC is a data and analytics company, not a law firm and not a tax advisor. Censum is independent and is not affiliated with Cook County or any government agency.