If you just opened a higher Cook County property tax bill, you are not alone. Cook County property tax bills rose again for at least the 32nd straight year, and most of the new weight landed on homeowners. The good news is that you hold real levers.
At Ownwell, we help homeowners cut what they owe through appeals and exemptions. Below, we break down how much bills rose, why it happened, and what you can do about it.
Key Takeaways
Bills rose for at least the 32nd straight year, with local governments seeking $743.8 million more, bringing the total to more than $19.9 billion.
Countywide, the median homeowner bill rose 4.4%, while the median business bill rose 2.6%.
Homeowners now cover about 80% of the new tax load, the fifth year in a row.
Where you live matters: the north and northwest suburbs saw the sharpest jump after their 2025 reassessment.
You can fight back by appealing your assessed value and claiming every exemption you qualify for.
How much did Cook County property tax bills rise this year?
Bills went up again across all three regions of the county. The Cook County Treasurer's Tax Year 2025 bill analysis shows local governments asked for $743.8 million more in taxes, bringing the total above $19.9 billion. That is an increase of about 3.9%, above 2025's 3.1% inflation rate.
Countywide, the median homeowner bill rose 4.4%. The median business bill rose 2.6%. More than 1.3 million homeowners saw higher bills, while about 226,000 saw a decrease, according to the Treasurer.
By region: city, north suburbs, south suburbs
Your increase depends on where you live and when your area was last valued. Cook County's triennial reassessment schedule reviews one-third of the county each year on a three-year cycle. Here is how the median homeowner bill moved by region.
Region | Median homeowner bill | Change |
|---|---|---|
City of Chicago | $4,597 | +3.2% |
North and northwest suburbs | $8,007 | +6.7% |
South and southwest suburbs | $6,468 | +3.4% |
In the north and northwest suburbs, where every property was reassessed in 2025, the median homeowner bill jumped 6.7% to $8,007. In that same region, the median commercial bill fell 3.5%. The south and southwest suburbs are being reassessed for 2026, and Chicago follows in 2027.
How Much Are You Over Paying?
Why Did My Cook County Property Tax Bill Go Up? The Real Drivers
Your bill climbed mainly because local governments asked for more money, and because value shifted from businesses onto homes. Three forces did most of the work.
1. Rising Government Levies
A levy is the total dollar amount a taxing body, such as a school district, requests each year. Most agencies asked for more in 2025. Of the county's 750 active taxing agencies, 641, or 85.5%, sought more taxes.
School districts drove the biggest dollar increase. They sought $474.9 million more, a 4.6% jump that outpaced inflation. Because schools make up the largest slice of most bills, that pushed many homeowners higher.
2. The Triennial Reassessment
Your assessed value is the figure Cook County uses to tax your home. In Cook County, it equals 10% of your home's fair market value, which is what your home would sell for today. Every three years, the Assessor sets a fresh value for your area.
When values rise at reassessment, bills often follow. The north and northwest suburbs were reassessed in 2025, which is why that region saw the steepest climb. Your township's turn drives much of your year-to-year swing.
Falling Commercial Values (And Why That Matters to You)
A property tax bill works like a pie. When one group's share shrinks, everyone else's slice grows to cover the same levy. Office buildings lost value, so their share dropped, and homeowners absorbed the difference.
The Treasurer's analysis, citing Crain's Chicago Business, reported that 28% of Chicago office space was unoccupied and more than 33% of suburban office space was vacant in 2025. Lower office values mean a smaller share for businesses and a larger share for homeowners.
Why Are Homeowners Paying More Than Businesses?
Homeowners pay more because the tax burden shifted onto them again. Homeowners shoulder about 80% of the increase, paying $593.4 million of the $743.8 million in new taxes, the fifth year in a row.
Appeals widened the gap. The Cook County Board of Review granted $1.3 billion in commercial reductions versus $397 million residential. When businesses win larger cuts, more of the levy lands on homes.
How a Cook County Property Tax Bill Is Actually Calculated
Your bill follows a clear chain: fair market value, assessed value, equalized assessed value, then the tax rate. Equalized assessed value (EAV) is your assessed value multiplied by a state equalization factor that keeps counties consistent.
The full formula runs like this:
Fair market value × 10% = assessed value. Assessed value × state equalization factor = EAV. EAV × local tax rate = your tax bill.
The numbers below are illustrative, not current rates, and they show what a successful appeal can do. This example uses a Chicago-area home, a sample equalization factor of 3.0, and a sample 7% tax rate.
Step | Before appeal | After appeal |
|---|---|---|
Fair market value | $300,000 | $270,000 |
Assessed value (10%) | $30,000 | $27,000 |
Equalized assessed value (EAV) | $90,000 | $81,000 |
Local tax rate | 7% | 7% |
Annual tax bill | $6,300 | $5,670 |
Annual savings | n/a | $630 |
A lower value at any step carries straight through to a smaller bill. That is why checking your assessed value is worth your time.
Is Your Higher Bill a Mistake? How to Check
Sometimes a higher bill is an error you can fix, so it's worth reviewing the details. Start with three quick checks before you pay.
Confirm your exemptions are applied, since a dropped exemption can spike your bill overnight.
Check your property record for incorrect square footage, bedroom counts, or features you don't have.
Compare your assessed value to recent sales of similar homes nearby.
If the county overcharged you in a prior year, you may qualify for a Certificate of Error refund. This process corrects a mistake on past bills and can return money you already paid.
How To Lower Your Cook County Property Tax Bill
You have two main levers you control: your assessed value and your exemptions. Used together, they can trim your bill before the next cycle.
Appeal Your Assessed Value
You can file a Cook County property tax appeal to challenge the county's value of your home. The Cook County two-appeal rule gives you two chances each year, first at the Assessor and again at the Board of Review.
Appeal windows open by township and close fast, so confirm your window with the Cook County Assessor. Appeals add up: our Cook County appeal analysis found homeowners have generated $2.8 billion in collective tax reductions through appeals.
Claim Every Exemption You Qualify For
Exemptions lower your taxable value, which lowers your bill. Most homeowners qualify for the Chicago homeowners exemption, and seniors may add more savings through the senior assessment freeze. Many owners simply never apply, so review and claim every exemption you qualify for.
Skipping relief is common. In our 2026 National Homeowner Survey, 74% of U.S. homeowners had never appealed their property tax bill; of those, 57% didn't know they could.
Unsure Which Exemptions You Qualify For?
If You Can’t Pay by the Due Date
Many homeowners pay property taxes through a mortgage escrow account. If you have no mortgage or escrow, you pay the county directly by the due date. The second installment of 2025 bills was due Thursday, October 1, 2026.
Those bills arrived about two months later than the usual early-August schedule, after a technology overhaul of the county's tax system delayed them, officials said. Late payments accrue interest, so pay what you can on time even while you appeal. Statewide relief remains uncertain, as the Cook County millionaire surcharge referendum shows.
How Ownwell can help Illinoisans
At Ownwell, we manage the full process, from filing your appeal and gathering evidence to handling paperwork and hearings. There are no upfront costs, and you only pay if you save. We also find and file the exemptions you may be missing.
Our results speak for themselves. Ownwell maintains an 88% success rate, saves customers an average of $774 a year, and holds a 4.7 rating across 3,000+ Google reviews.
Start your Cook County appeal with zero upfront cost.
Frequently Asked Questions
Why did my Cook County property tax bill go up in 2026?
Local governments levied $743.8 million more in taxes, and falling commercial values shifted a larger share onto homes. If your township was reassessed in 2025, your increase was likely sharper.
How much did Cook County property tax bills rise this year?
Countywide, the median homeowner bill rose 4.4% and the median business bill rose 2.6%. In the north and northwest suburbs, the median homeowner bill rose 6.7% to $8,007.
Why are homeowners paying more than businesses?
Homeowners paid $593.4 million of the $743.8 million increase, about 80% of all new taxes, for the fifth year in a row. The Board of Review also granted far larger reductions to businesses than to homes.
When were second-installment 2025 bills due?
Second-installment 2025 bills were due Thursday, October 1, 2026, later than the usual August 1 date. Late payments accrue interest.
How can I lower my Cook County property tax bill?
Appeal your assessed value and claim every exemption you qualify for, and confirm your township's appeal window with the Cook County Assessor. We can handle both for you with no upfront cost.
