Update, November 13, 2026: Jefferson Township’s 2026 Assessor appeal window has closed; the last file date was November 12, 2026 (Assessor calendar, last updated November 6, 2026). The Board of Review is the next step, but its 2026 schedule still lists only Groups 1–4, which do not include Jefferson, so no Board of Review dates are posted yet. In Chicago, North Chicago (November 24) and South Chicago (December 15) are still open at the Assessor.
Owners of property in Chicago’s Jefferson Township could file a free 2026 property tax appeal with the Cook County Assessor’s Office until Thursday, November 12, 2026, the last file date on the Assessor’s 2026 Assessment & Appeal Calendar (last updated October 28, 2026).
Facts checked October 30, 2026 · Chicago First Time Home Buyer editorial team
What is the Jefferson Township property tax appeal deadline in 2026?
The Assessor’s calendar lists Jefferson Township with a notice date of September 29, 2026 and a last file date of November 12, 2026. The appeal window was open as of October 30, 2026 and closed after November 12. The exact last date for your property is also printed on your notice.
| Item (Jefferson Township, City of Chicago, 2026 assessment) | Date or amount | Source |
|---|---|---|
| Assessor notice date | Sept. 29, 2026 | Cook County Assessor calendar, updated Oct. 28, 2026 [1] |
| Assessor last file date | Nov. 12, 2026 (closed) | Cook County Assessor calendar, updated Oct. 28, 2026 [1] |
| Fee to file an Assessor appeal | $0 (free) | Cook County Assessor, How Appeals Work [2] |
| Board of Review filing window | Not yet announced (2026 schedule lists Groups 1–3 only, which do not include Jefferson) | Cook County Board of Review 2026 dates and deadlines [6] |
How does Jefferson compare with other Chicago townships this year?
All dates below are the Assessor’s 2026 last file dates for City of Chicago townships, from the same calendar (last updated October 28, 2026), with status as of October 30, 2026.
| Chicago township | Assessor notice date | Assessor last file date (2026) | Status Oct. 30, 2026 |
|---|---|---|---|
| Rogers Park | Apr. 17 | June 1 | Closed |
| Lakeview | May 28 | July 13 | Closed |
| West Chicago | July 10 | Aug. 21 | Closed at the Assessor (Board of Review open Oct. 8 – Nov. 6, 2026) |
| Hyde Park | Aug. 26 | Oct. 8 | Closed |
| Lake | Sept. 16 | Oct. 29 | Closed |
| Jefferson | Sept. 29 | Nov. 12 | Open |
| North Chicago | Oct. 9 | Nov. 24 | Open (see North Chicago Township appeals close Nov. 24) |
| South Chicago | Oct. 30 | Dec. 15 | Open (dates added to the Assessor’s calendar Oct. 30, 2026; see South Chicago Township appeals close Dec. 15) |
For the full calendar and how the two appeal steps fit together, see Chicago property tax appeal deadlines, fall 2026 and our guide to how to appeal your property tax assessment in Chicago. Earlier township posts cover Lake and West Chicago.
Where is Jefferson Township in Chicago?
Jefferson Township covers much of Chicago’s Northwest Side. The Assessor’s Office describes its boundaries this way (August 20, 2021 release):
- East: Western Avenue.
- South: North Avenue.
- West: Harlem Avenue north to the Des Plaines River, then north to Higgins.
- North: largely Higgins and Devon avenues, extending as far as Touhy Avenue.
If your home is close to one of these streets, confirm your township with the Assessor’s Office before relying on the November 12 date.
Is Jefferson Township being reassessed in 2026?
No. The Assessor’s 2026 calendar says the south and west suburbs are being reassessed in 2026, while properties in the City of Chicago and the north suburbs are reassessed only if an individual property has significant changes, such as division work. Cook County reassesses each township once every three years.
Jefferson Township was last reassessed in 2024. In its October 2, 2024 release, the Assessor reported that total assessed value in Jefferson Township grew 24% in that reassessment, and that the median sale price of single-family homes in the township in 2023 was $393,000, compared with the Assessor’s median estimated market value of $366,000 for the same class of homes. An appeal this year is a chance to correct a value that has been in place since that reassessment.
Is a Jefferson Township property tax appeal worth filing?
The Assessor’s Office suggests considering an appeal in two situations:
- The property characteristics on your notice are wrong (for example, square footage).
- The estimated market value is well above what you think the property would sell for.
If the characteristics are correct and the estimated value is within about 10% of your own estimate, the Assessor says an appeal is unlikely to change the assessed value enough to matter.
Evidence has to be filed with the appeal, not later. For an overvaluation appeal, the Assessor’s residential appeals page points to recent closing statements and the purchase prices of similar homes. For wrong characteristics, it lists dated photos, a property deed or other documents. Appraisals must be USPAP compliant. You do not need to list comparable properties for a uniformity appeal; the Assessor’s analysts review comparables themselves.
How do you file, and do you need to hire anyone?
Filing is free and can be done online in as little as 20 minutes, according to the Assessor’s Office, which says you do not need to hire anyone to file for you. Paper forms are available if you cannot file online. Mailings from private tax firms offering to appeal for a fee do not come from the Assessor’s Office.
What does this mean if you just bought, or are buying, in Jefferson Township?
- If you bought recently: your closing statement is the kind of evidence the Assessor names for an overvaluation appeal. Also make sure you have applied for the Cook County homeowner exemption, which new owners must apply for.
- If you are still shopping: use the current assessment and recent tax bills to estimate your Chicago property tax bill before you make an offer, rather than relying on a listing’s tax figure.
- If you miss November 12: the Assessor says you may appeal in a following year when your township is open for appeals, and the Board of Review is a separate second step once it announces Jefferson’s window.
More on owning a home here: After you buy a home in Chicago.
Common questions
When is the Jefferson Township property tax appeal deadline in 2026?
The Cook County Assessor’s last file date for Jefferson Township is Thursday, November 12, 2026, according to the Assessor’s 2026 calendar last updated October 28, 2026.
Does it cost anything to appeal my property taxes in Cook County?
No. Filing an appeal with the Cook County Assessor’s Office is free, and the office says you do not need to hire anyone to file it.
Is Chicago being reassessed in 2026?
No. The Assessor’s 2026 calendar says the south and west suburbs are reassessed in 2026; City of Chicago properties are reassessed only if an individual property has significant changes. Jefferson Township was last reassessed in 2024.
Can Jefferson Township owners appeal to the Board of Review in 2026?
The Board of Review had not announced a 2026 window for Jefferson Township as of October 30, 2026; its published 2026 schedule lists only Groups 1–3, which do not include Jefferson.
Sources
- Cook County Assessor’s Office, Assessment & Appeal Calendar (last updated Oct. 28, 2026; read Oct. 30, 2026).
- Cook County Assessor’s Office, Overview of How Appeals Work (read Oct. 30, 2026).
- Cook County Assessor’s Office, Residential Appeals (read Oct. 30, 2026).
- Cook County Assessor’s Office, Property reassessments released for Jefferson Township (Aug. 20, 2021; township boundaries).
- Cook County Assessor’s Office, Property Values for Jefferson Township Released (Oct. 2, 2024; 2024 reassessment figures).
- Cook County Board of Review, Dates and Deadlines, 2026 Session (PDF; read Oct. 30, 2026).