The 60-second version
The Board of Review appeal window for Oak Park Township opened August 3, 2026 and closes September 1, 2026. Appeals are filed township by township in Cook County, so this window applies to every Oak Park parcel. Miss it and the next chance is the following venue or the following year. Check your parcel now (free lookup) or see every township's current dates.
What the Board of Review window means for Oak Park homeowners
Cook County property owners get two cracks at an assessment each year: first at the Assessor, then at the Board of Review. The two are independent — a loss (or a pass) at one does not prevent filing at the other, and the Board decides tens of thousands of residential appeals every cycle. Oak Park sits in Cook County's south triad; in a reassessment year the whole township's values move at once, which is when uniformity appeals matter most.
What Oak Park appeals actually did, year by year
These are county-published outcomes for ALL residential (Class 2) appeals filed in Oak Park Township — every appellant, represented or not, not this firm's results:
| Tax year | Venue | Appeals decided | Received a reduction | Avg. cut (of AV, winners) |
|---|---|---|---|---|
| 2026 | Assessor | 9,662 | 2,487 (26%) | 9.0% |
| 2025 | Board of Review | 4,083 | 1,568 (38%) | 7.1% |
| 2025 | Assessor | 2,595 | 364 (14%) | 7.8% |
| 2024 | Board of Review | 4,719 | 2,262 (48%) | 7.1% |
| 2024 | Assessor | 3,154 | 400 (13%) | 7.9% |
| 2023 | Board of Review | 8,148 | 3,841 (47%) | 7.4% |
| 2023 | Assessor | 9,486 | 3,533 (37%) | 10.2% |
| 2022 | Board of Review | 3,266 | 984 (30%) | 6.9% |
| 2022 | Assessor | 1,932 | 242 (13%) | 12.1% |
| 2021 | Board of Review | 4,568 | 1,771 (39%) | 7.5% |
| 2021 | Assessor | 3,521 | 694 (20%) | 20.5% |
| 2020 | Board of Review | 8,384 | 3,149 (38%) | 7.6% |
| 2019 | Board of Review | 3,842 | 1,654 (43%) | 9.0% |
| 2018 | Board of Review | 4,092 | 2,618 (64%) | 10.0% |
| 2017 | Board of Review | 8,261 | 6,358 (77%) | 10.4% |
| 2016 | Board of Review | 2,396 | 1,315 (55%) | 9.6% |
| 2015 | Board of Review | 3,785 | 2,532 (67%) | 9.9% |
| 2014 | Board of Review | 5,869 | 4,504 (77%) | 9.7% |
| 2013 | Board of Review | 3,727 | 2,634 (71%) | 11.1% |
| 2012 | Board of Review | 3,782 | 3,050 (81%) | 10.3% |
| 2011 | Board of Review | 5,482 | 3,758 (69%) | 9.3% |
| 2010 | Board of Review | 1,823 | 1,169 (64%) | 13.9% |
| 2004 | Assessor | 507 | 225 (44%) | 10.8% |
| 2003 | Assessor | 515 | 159 (31%) | 9.3% |
| 2002 | Assessor | 2,906 | 950 (33%) | 6.7% |
| 2001 | Assessor | 328 | 128 (39%) | 15.4% |
Read these within their year: reassessment years pull win rates and cut sizes around for the whole township, so the fair comparison is same-year, same-class, same-venue.
Oak Park's tax math: why the window is worth 15 minutes
The median Oak Park residential assessment is about $45,000 of assessed value. At the state equalizer (3.03) and Oak Park's average local rate (~11.21%), that assessment produces roughly $15,285 of gross tax before exemptions. Among last cycle's successful Oak Park appeals, the average reduction was about 7.1% of assessed value — on the median home, arithmetic of roughly $1,085 per year. Your parcel's numbers are what matter: run them in the calculator.
How to appeal your Oak Park assessment before September 1, 2026
- Look up your property and compare its assessment per square foot against comparable Oak Park homes — uniformity is the argument the county's own process is built around.
- Confirm the window on the deadlines page — dates are per township and per venue.
- File before September 1, 2026. Evidence can usually be supplemented after filing within the venue's posted evidence period.
Fees are contingency-only (no upfront cost); see the appeal FAQs for how the process runs end to end.
What happens after you file
The Board of Review reviews the complaint against its own records and the comparables submitted. Most residential appeals are decided on the papers — no hearing, no visit, and in practice a residential appeal results in either a reduction or no change. Decisions typically arrive after the township closes, and a certified change flows into the second-installment bill.
If you miss this window
The two venues are sequential: an Oak Park owner who misses the Board of Review window is done for this cycle at the county level, though the following year brings both windows again. The deadlines page tracks every township's next window as the county publishes it.
