What actually happens to property tax appeals in Cook County

Not our estimate. The Assessor publishes every appeal decision — the case, the township, the value before and after, and whether anything changed. This page counts them. 1,807,534 decisions, 2021–2026.

16.7%of appeals won a reduction 16.5%–16.8% at 95%

429,298appeals decided 18,020 still open

6.8%typical cut, when one was won median over 69,116 reductions

You will see higher numbers advertised. Appeal services routinely quote success rates upward of 80%. Those are the vendor's own figures for the cases they chose to take, and there is no way to check them. This is the county counting every appeal filed with it, including the ones that lost.

Does hiring someone help?

Whether an agent helps is not settled here: the advantage has changed sides between years, ahead in 2 and behind in 4. A single combined figure would report whichever side the window happened to favour.

2021: +8.02022: -1.22023: -2.32024: +0.42025: -2.82026: -6.0

Each year: how many percentage points better an agent did than an owner filing alone. Negative means the owner did better.

Firms that file on your behalf commonly take a third of the first year's saving. This is the county's own record of how the two groups actually did.

By township

Where a property sits changes its odds substantially. Townships with fewer than 30 decided appeals show no rate, because a percentage from a handful of cases is not a rate.

River Forest 29.2% of 3,320 decided Barrington 25.3% of 3,501 decided Leyden 25.1% of 11,013 decided New Trier 24.8% of 21,741 decided Riverside 24.3% of 3,228 decided Calumet 24.2% of 388 decided Oak Park 24.0% of 12,850 decided Niles 24.0% of 19,680 decided Berwyn 21.6% of 6,904 decided Northfield 21.3% of 21,568 decided Evanston 19.4% of 15,373 decided Hyde Park 19.4% of 4,962 decided Maine 19.3% of 33,373 decided Cicero 18.9% of 4,634 decided Palos 17.9% of 10,940 decided Lyons 17.6% of 6,735 decided West Chicago 17.6% of 16,649 decided Lemont 17.5% of 1,508 decided Lake 17.3% of 5,725 decided Palatine 16.4% of 22,798 decided Thornton 15.4% of 4,587 decided Norwood Park 15.3% of 4,976 decided Wheeling 14.8% of 31,208 decided Jefferson 14.8% of 15,889 decided Bloom 13.7% of 2,266 decided Worth 13.1% of 5,391 decided Hanover 13.0% of 11,437 decided Proviso 12.7% of 4,565 decided Schaumburg 12.6% of 22,649 decided Bremen 12.2% of 3,722 decided Elk Grove 12.2% of 19,039 decided Lake View 11.9% of 22,428 decided Rogers Park 11.7% of 3,715 decided Rich 11.5% of 2,557 decided Stickney 11.5% of 1,787 decided North Chicago 10.2% of 23,738 decided Orland 10.1% of 3,842 decided South Chicago 4.4% of 18,612 decided

Source. Cook County Assessor, published appeal decisions (dataset y282-6ig3), refreshed from the county's open data API. Every figure on this page is a count of those records. Nothing is estimated, modelled or written by a language model. Undecided appeals are excluded from rates rather than counted as losses. Rates carry a 95% Wilson interval, and none is shown below 30 decided appeals.