The Cook County Assessor's 2026 reassessment of the south and west suburbs is landing, and the numbers are large. Comparing each home's new 2026 assessment with its final 2025 assessment, the median residential increase is 27% in Lemont, 25% in Lyons, 24% in Palos and Berwyn, 22% in Worth, 21% in Stickney, 20% in Cicero, Bremen and Orland, and 19% in Proviso. In every one of those townships more than 88% of homes went up. Calumet is the outlier at 9%, with a third of homes unchanged or lower.
2026 reassessment by township
Residential (Class 2) parcels only. "2025" is the final Board of Review value for 2025; "2026" is the value on this year's reassessment notice. Source: Cook County Assessor assessment files as loaded through September 27, 2026.
| Township | Homes compared | Median change | Homes that went up | Median 2026 assessed value | Assessor window |
|---|---|---|---|---|---|
| Lemont | 8,589 | +27.1% | 98.6% | $57,001 | August 17 – September 29, 2026 |
| Lyons | 38,177 | +25.1% | 96.9% | $35,001 | July 23 – September 3, 2026 |
| Palos | 20,493 | +24.2% | 97.5% | $33,000 | June 3 – July 17, 2026 |
| Berwyn | 14,107 | +24.1% | 94.8% | $31,000 | May 20 – July 6, 2026 |
| Worth | 57,017 | +22.2% | 96.9% | $25,000 | September 1 – October 15, 2026 |
| Stickney | 13,175 | +21.1% | 98.7% | $27,000 | June 29 – August 12, 2026 |
| Cicero | 14,520 | +20.2% | 97.1% | $26,000 | June 17 – July 31, 2026 |
| Bremen | 40,996 | +20.0% | 88.0% | $21,000 | August 12 – September 24, 2026 |
| Orland | 37,567 | +19.9% | 98.8% | $38,000 | September 24 – November 6, 2026 |
| Proviso | 47,544 | +19.0% | 89.0% | $28,000 | September 14 – October 27, 2026 |
| Calumet | 5,269 | +9.1% | 66.2% | $13,000 | August 20 – October 2, 2026 |
Townships reassessed in earlier years moved less than 1% this year, as expected: Leyden, Elk Grove, Maine, New Trier, Northfield and Barrington in the north, and Lake View, West and Hyde Park in the city, all show a median change of 0.0%.
What a 22% assessment increase does to a bill
Assessed value is 10% of the Assessor's opinion of market value, so a median Worth home assessed at $25,000 is being valued at about $250,000. The bill is that assessed value, times the state equalizer (3.03 for 2025), times the local tax rate, minus exemptions. Rates are set later by the taxing bodies' levies, so a township-wide increase does not raise everyone's bill by the same percentage. What it does change is your share: if your home went up 30% while the township median went up 22%, you will carry more of the levy than last year. That gap is exactly what an appeal tests.
Reassessment year is when uniformity appeals work
In a reassessment year the whole township is revalued at once from a mass-appraisal model, and the model gets individual homes wrong in both directions. The argument that wins is uniformity: your home is assessed higher per square foot than comparable homes on similar lots in the same neighborhood code. The Assessor's own 2025 results in these townships show what happens when owners make that argument at the Board of Review: 37% of Worth's residential Board appeals received a reduction, 36% in Lyons and Bremen, 41% in Berwyn, 50% in Cicero, with average cuts of 7–9% of assessed value. The Assessor's first-pass appeal reduced 10–15% of appellants in the same townships.
What to do this month
- Read the notice. Check the characteristics the Assessor is using: square footage, bedrooms, basement finish, garage, exterior. A wrong characteristic is the simplest appeal there is.
- Compare, do not just complain. Pull five to eight comparable homes and compare assessed value per square foot. Our free property check does this from the county's own data in under a minute.
- File in the right window. The last Assessor windows of the south and west suburban cycle are Worth (to October 15), Proviso (to October 27) and Orland (to November 6); see the Worth, Proviso and Orland numbers. For the other townships the next step is the Board of Review, which opens each township after the Assessor certifies it; the dates are on the deadlines page as the county publishes them.
- Check your exemptions on the second-installment bill due October 1. A missing Homeowner or Senior exemption is fixed with a Certificate of Error, not an appeal.
Our fee is 25% of the first year's savings and nothing if there is no reduction. Start with your address to see where your home stands against the homes around it.
