Independent service. Not affiliated with Cook County, the Cook County Assessor or the Board of Review. Filing with the county is free.
Lemont property tax appeal 2026
All of Lemont's homes in our data are in Lemont Township, so Lemont homeowners follow Lemont Township's 2026 appeal dates. Appeals go to the Cook County Assessor and the Board of Review, not to the city. Lemont also reaches into a neighboring county; this page covers its Cook County part.
Lemont appeal deadlines 2026 by township
| Township | Assessor | Board of Review |
|---|---|---|
| Lemont Township100% of Lemont's parcels | closed Sep 29 | not announced yet |
Dates: Assessor's calendar and Board of Review dates, checked on October 9, 2026.
Lemont homes at a glance
- 7,030 residential (class 2) parcels, of them 5,336 houses and 232 condominium units.
- Main ZIP codes: 60439.
Property tax on a typical Lemont house
Our estimate for the median house in Lemont: about $9,900 a year (median 2025 assessed value $47,192). An appeal lowers the assessed value, which is one part of that bill; exemptions, the state equalizer and local tax rates are the others.
Our calculation from Cook County open data, not official figures and not your bill: 2025 final assessed value × the 2025 state equalizer × the 2025 tax rate of the home's tax code, minus the homeowner exemption, for 5,253 houses (classes 202–209, 234, 278).
Lemont homeowners at the Board of Review last year
For tax year 2025, 415 Lemont homeowners filed on their own at the Board of Review for a house, and 215 of them got a lower value.
Private houses, appeals filed without an attorney. Source: Cook County Board of Review open data (Appeal Decision History), our analysis, not official figures. Results for every township.
How to appeal in Lemont
- Find your township. It is on your assessment notice; the free check below shows it from your address.
- File with the Cook County Assessor while your township's window is open. Filing is free and online; you don't need to hire anyone.
- Board of Review is a second chance. When the Board opens your township, you can file there too, also free.
Step by step: how to appeal · choosing comparables · Assessor or Board of Review.
Questions
Which township is Lemont in?
Lemont is in Lemont Township.
What is the Lemont property tax appeal deadline in 2026?
It depends on the township. Lemont Township: Assessor last file date September 29, 2026.
Do I appeal to the City of Lemont?
No. Assessment appeals in Cook County go to the Cook County Assessor and then the Board of Review. Filing with either is free.
How much property tax does a typical Lemont house pay?
Our estimate for the median house is about $9,900 a year, from 2025 assessed values and tax rates in county open data. It is not an official figure; your bill shows your own amount.
About Cook Tax Check
Cook Tax Check is an independent service run by Virix Ltd. We are not the county and not a law firm. Our check of your home against similar homes is free. If it looks worth appealing, our document packet costs $49. Savings Guarantee: no savings? Your next appeal is on us. If the Assessor says no, we prepare your Board of Review appeal for free, and if neither office lowers your value, your appeal package for next tax year is on us (terms). You file yourself, for free, on the county's website — we don't file or represent anyone. See a sample packet.
Nearby
Sources
- Cook County Assessor — assessment calendar and deadlines
- Board of Review — dates and deadlines
- Cook County open data — Parcel Universe
- Cook County open data — Assessed Values
- Cook County Assessor — residential appeals
Dates last checked against the Assessor's calendar and the Board of Review's published dates on October 9, 2026. If anything here differs from the county's own pages, the county's pages win.