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Oak Park Township: 2026 appeal windows have closed

Places with the most homes in Oak Park Township: Oak Park.

Closed for 2026

Both 2026 windows have closed (Board of Review: September 1, 2026).

What is still possible: an appeal to the Property Tax Appeal Board (state level) after the Board of Review decision (how PTAB works), claiming a missed exemption for past years (Certificate of Error), and preparing for next year's window.

Oak Park Township 2026 dates

Assessor notices mailed	May 6, 2026
Assessor appeals open	May 6, 2026
Assessor last file date	June 18, 2026
Board of Review open	August 3, 2026
Board of Review close	September 1, 2026
Board of Review evidence due	September 11, 2026

Sources: Assessor's assessment calendar, Board of Review 2026 open/close dates (PDF). Checked on October 2, 2026.

Was Oak Park Township reassessed in 2026?

Yes. Oak Park is in the south and west suburbs, which the Assessor reassesses in 2026. Cook County reassesses each area once every three years, so every owner here gets a Reassessment Notice with the property's characteristics and an updated estimated market value.

How values moved here: for the typical house, the first-pass 2026 assessed value is +23.4% compared with the final 2025 value (median of 11,338 houses with both values). Our calculation from Cook County open data (Assessed Values), not an official figure. Your own home can differ a lot from the typical one.

The Assessor publishes residential valuation reports for each township it reassesses: Assessor's valuation page for Oak Park. A higher value does not mean the bill goes up by the same amount: your bill depends on your share of the total value, exemptions and local levies.

Source: Assessor's calendar.

Oak Park Township at a glance

17,063 residential (class 2) parcels, including 5,356 condominium units.
Cities and villages with the most homes: Oak Park (17,025).
Main ZIP codes: 60302, 60304, 60301.

Our calculation from Cook County open data (Assessor Parcel Universe), October 5, 2026. Townships, cities and ZIP codes overlap, so the address check is the reliable way to confirm yours.

Appeals in Oak Park Township last year

For tax year 2025, 4,083 residential property appeals from Oak Park Township were filed at the Board of Review, and 2,596 at the Assessor. Appealing is a routine step for many owners here.

Our count from Cook County open data (Board of Review Appeal Decision History, Assessor Appeals), counted by property, not official figures.

How to file in Oak Park Township

Confirm your PIN and township. Use the Assessor's address search or our free check below.
Check the notice. The Assessor's rule of thumb: if the characteristics on your notice are correct and the estimated market value is within 10% of what you think your home is worth, an appeal is unlikely to change much. Wrong square footage, rooms or other characteristics are a reason to appeal.
File online with the Assessor. On the county's online appeal site choose the residential appeal (or "Residential with Comparable Grid" if you argue lack of uniformity). The Assessor says filing is free and can take as little as 20 minutes, and that you don't need to hire anyone.
Comparables are optional. Assessor analysts review similar homes themselves. You may attach up to 6 comparable PINs from your neighborhood that resemble your home in size and style.
Board of Review is a second chance. When the Board opens Oak Park, you can file there too (online, free). Individual owners may represent themselves; the Board's decision sets the final county value for the year.

More detail: how to appeal step by step · Assessor or Board of Review · choosing comparables.

What our packet adds

Filing is free and you can do it without us. If our free check says your home is assessed above similar homes, you can buy a document packet for $49: the comparable homes, the value to ask for, suggested text and step-by-step filing instructions for Oak Park Township.

One-time $49. No subscription and no share of your savings.
Refund: if you file using the packet and the county does not lower your assessed value, send us the decision within 30 days and we refund the full price (terms).
You file yourself on the county's site. We don't file or represent anyone, and no result is guaranteed.

See a sample packet

Questions

What is the Oak Park Township appeal deadline in 2026?

The Assessor's last file date for Oak Park Township is June 18, 2026. The Board of Review window is August 3, 2026 to September 1, 2026.

I missed the Assessor deadline. What now?

Both 2026 windows have closed. You can still look at a Property Tax Appeal Board appeal after a Board of Review decision, claim missed exemptions for past years, and appeal next year.

Should I appeal to the Assessor or the Board of Review?

You can do both. The Assessor's window comes first; the Board of Review is a separate agency and its decision sets the final county value for the year.

Was Oak Park Township reassessed in 2026?

Yes. The south and west suburbs, including Oak Park, are reassessed in 2026, so owners get a Reassessment Notice with an updated estimated market value.

Can appealing raise my assessment?

Under Illinois law (35 ILCS 200/16-95) the Board of Review may not increase an assessment unless the owner is first notified in writing and given a chance to be heard.

I think I missed an exemption. Can I get it back?

Missed homeowner and other exemptions for past years can be requested from the Assessor through a Certificate of Error. The Assessor's page currently lists tax years 2021 to 2025 for the homeowner exemption.

Nearby townships

All 38 Cook County townships and deadlines

Sources

Dates last checked against the Assessor's calendar and the Board of Review's published dates on October 2, 2026. If anything here differs from the county's own pages, the county's pages win.