Cook County's 2026 assessment roll lists 374 parcels in the cooperative class, which the Assessor numbers 2-13. In a co-op, the corporation owns the building and its PIN. The county sends one tax bill to the co-op. Each shareholder pays a share of it through monthly charges.
181 of those parcels are in Chicago, clustered in lakefront neighborhoods: the Near North Side has 32, Hyde Park 26, Lincoln Park 17 and Lake View 13. Evanston has 33. The biggest group in the county is in Hometown, with 96. A building can have more than one PIN, so parcels are not the same as buildings.
Shareholders can still get the homeowner, senior and other exemptions. But the paperwork, the savings and any appeal all run through the co-op. Here is how each piece works, and what to ask your board.
Quick Answer
In a Cook County co-op, the co-op files one homeowner exemption application with the Assessor for each building PIN. It counts the units where a member lived as their main home on January 1, and the building's exemption is $10,000 of equalized assessed value (EAV) for each of those units. Senior shareholders apply for the senior exemption themselves, with a stock certificate or occupancy agreement. Illinois law requires the co-op to pass each exemption's savings to the shareholder who qualified for it. Only the co-op can appeal the building's assessment, and at the Board of Review it must use an attorney. Ask your board what it filed, how many units it counted, how the savings are credited, and whether it appealed.
What the county record shows
On the tax year 2024 record (bills paid in 2025):
- Bills: 373 co-op parcels were billed $42.2 million in total. The median co-op parcel's bill was $15,659.
- Homeowner exemption: 360 of the 373 parcels carried it. Together they took $82.9 million off EAV, the same as about 8,300 full $10,000 exemptions.
- Senior exemption: 289 parcels and $31.3 million of EAV, about 3,900 full $8,000 exemptions.
- Senior Freeze: 158 parcels.
Exemptions on a building can also thin out. On the tax year 2023 record, only 238 co-op parcels carried a homeowner exemption, down from 309 in 2022. In 2024 the count was back to 360. The record doesn't say why. But when an exemption is missing from the building's bill, the shareholders who qualified for it pay more.
How co-op exemptions work
The co-op files the homeowner exemption. Co-op owners can't use the Assessor's regular online filing system. Instead, an officer or authorized agent of the co-op completes the Assessor's cooperative application, one per building PIN. It lists:
- the total units in the co-op,
- the total shares, with an itemized list of shares for each unit, and
- how many units were members' principal residences on January 1, seniors included.
The co-op emails or mails it to the Assessor. The Assessor publishes the form for each tax year, and it asks for the January 1 count for that year.
The building's exemption is a per-unit amount times qualifying units. State law sets co-op exemptions this way: the maximum amount, multiplied by the number of units occupied by shareholders who qualify. In Cook County that is $10,000 of EAV per unit for the homeowner exemption and $8,000 per unit for the senior exemption. The Senior Freeze and the disability exemption are also counted unit by unit.
Seniors file in their own names. The Assessor asks co-op owners applying for the senior exemption to include a stock certificate, occupancy agreement or trust agreement with the application.
The savings belong to the shareholder who qualified. Illinois law says the co-op or its management must credit each exemption's savings only to the tax share of the owner who qualified. It can't spread them across the building. Under the same law, refusing on purpose to pass the savings along is a misdemeanor.
What that is worth. On tax year 2024 bills, nearly all Chicago co-op parcels had a tax rate of about 6.62%. At that rate:
| Exemption | EAV removed per qualifying unit | Yearly savings at 6.62% |
|---|---|---|
| Homeowner | $10,000 | about $662 |
| Senior | $8,000 | about $530 |
| Both | $18,000 | about $1,191 |
Your building's own rate is printed on its second-installment bill.
Who can appeal the building's assessment
The co-op, not the shareholder. The building has one owner of record: the co-op corporation. The Board of Review's rules let individuals represent only property titled in their own names. Corporations, associations and other entities must be represented by an attorney. Co-op units don't have their own PINs; they are listed under the building's. So a Board appeal comes from the co-op, through its lawyer.
The Assessor's office says you don't need to hire anyone to appeal there, and filing is free. Anyone filing for an owner needs the Assessor's authorization form.
The record matches the rules. From tax year 2019 through 2025, the Board issued 1,077 decisions on co-op parcels. All but 3 were filed by attorneys. The Board reduced 264 of them, or 24.5%.
- Tax year 2024, Chicago's last reassessment year: 180 Board decisions and 45 reductions. At the Assessor's stage that year, 83 of the 125 co-op parcels appealed got a change.
- Tax year 2025: 142 Board decisions and 16 reductions. Of the 126 no-change decisions, 84 were "administrative" no-changes. A filer asks for one to move the case on to the state Property Tax Appeal Board or to court.
When the Board explains a co-op decision, its reason codes describe a "condominium/cooperative analysis" of sales, occupancy, appraisals and, where it fits, income and expenses. That is the evidence the co-op's counsel will need.
Watch the calendar. Chicago is reassessed next in 2027, the year city co-op values reset. Each township's appeal windows are on the Assessor's and Board's own calendars. See what Chicago owners can do before 2027.
What to ask your board
- Did the co-op file the Assessor's cooperative homeowner exemption application for the current tax year? How many units did it count as members' main homes on January 1?
- Does the building's latest second-installment bill show a homeowner exemption, and senior lines if seniors live here? How do they compare with last year's?
- How are exemption savings credited to me? Which line on my statement shows it?
- Have senior shareholders been told to file their own senior exemption, and the Senior Freeze if they qualify?
- If an exemption was missed in a past year, will the board use the Assessor's refund process (it calls it a Certificate of Error) to recover it?
- Did the co-op appeal the building's assessment at the Assessor and the Board this cycle? Who is our counsel, and what happened?
- What is the plan for our township's next reassessment, which for Chicago is 2027?
Where Censum fits
At /exemptions you can enter a PIN and see, for free, which exemptions are on its record. For a co-op, that means the building's PIN. A co-op building's Board appeal has to come from the co-op's attorney, so for a shareholder the useful steps are the record check and the questions above. If you also own a condo or house in Cook County, /win shows that home's appeal odds and its open window.
The numbers behind this article
- Parcel counts: Censum's tabulation of the Assessor's Parcel Universe dataset, class 2-13, assessment year 2026 (373 parcels in 2024 and 372 in 2025). These count parcels, not buildings.
- Bills, exemptions and rates: Censum's tabulation of PTAXSIM, the Cook County Assessor's Office research database, class 2-13, tax years 2022 through 2024. The Assessor describes PTAXSIM results as not official. "Full exemption equivalents" divide total exemption EAV by $10,000 or $8,000; many parcels carry partial amounts, so they are not unit counts. The 6.62% rate is the median tax code rate on Chicago co-op parcels in tax year 2024.
- Appeals: Censum's tabulation of the Board of Review Appeal Decision History dataset (tax years 2019 through 2025) and the Assessor's Appeals dataset (tax year 2024), PIN-level, class 2-13. "Attorney-filed" uses the Board dataset's attorney code; administrative no-changes are its no-change reason 8.
FAQ
Can I apply for the homeowner exemption on my co-op unit myself?
Not through the regular online system. The co-op's officer or agent files one cooperative application per building PIN, counting every qualifying unit.
Do seniors apply on their own?
Yes, for the senior exemption. The Assessor asks co-op owners to include a stock certificate, occupancy agreement or trust agreement with the application.
How do I know the savings reached me?
Ask the board which line on your statement shows it. State law requires the co-op to credit each exemption's savings only to the shareholder who qualified.
Can I appeal my unit's assessment?
No. Co-op units are listed under the building's PIN, and the building has one owner of record. The co-op files the appeal, and at the Board of Review it must use an attorney.
Is a co-op taxed like a condo?
No. Each condo unit has its own PIN and bill, and the owner applies for exemptions directly. A co-op gets one bill for the building. For condo buildings, see condo association appeals.
Do county exemption forms cost anything?
No. The Assessor's exemption applications and appeals are free to file.
Sources
- Cook County Assessor, Homeowner Exemption (including "Cooperative Properties: How to Apply")
- Cook County Assessor, 2025 Homeowner Exemption Application, Cooperative Apartment Buildings (PDF)
- Cook County Assessor, Senior Exemption
- Cook County Assessor, Definitions for the Classification of Real Property, revised 12/16/24 (PDF)
- Cook County Assessor, Overview of How Appeals Work
- Cook County Board of Review Official Rules, Rule 1, last updated July 27, 2026
- Cook County Board of Review, decision reason codes (BOR Form 195, PDF)
- Illinois Property Tax Code, 35 ILCS 200/15-175 (general homestead exemption; cooperative paragraph and subsection (g))
- 35 ILCS 200/15-170 (senior citizens homestead exemption; subsection (b) on cooperatives)
- 35 ILCS 200/15-172 (Senior Citizens Assessment Freeze; cooperatives)
- 35 ILCS 200/15-168 (homestead exemption for persons with disabilities; subsection (c) on cooperatives)
- Censum tabulation of the Assessor Parcel Universe (Historical) dataset (Cook County open data), class 2-13.
- Censum tabulation of PTAXSIM (Cook County Assessor's Office), tax years 2022-2024, class 2-13.
- Censum tabulation of the Board of Review Appeal Decision History dataset and the Assessor Appeals dataset (Cook County open data), class 2-13.
Sources accessed November 11, 2026.
Next step
Check your building's exemption lines before the next board meeting. Check exemptions on a PIN
Censum LLC is a data and analytics company, not a law firm and not a tax advisor. Censum is independent and is not affiliated with Cook County or any government agency.