In tax year 2026, 646 Cook County parcels in the main business incentive classes are in their step-up years. 379 are at 15% of market value in year 11. 267 are at 20% in year 12, the last year before the full 25% commercial and industrial level.
Most parcels that reach year 12 do not come back to 10%. Of 540 year-12 parcels in tax years 2023 through 2025, 473 (87.6%) were in an ordinary commercial or industrial class the next year. 54 (10.0%) were back at the 10% level, which is what a renewal looks like in the record.
A lapse is expensive. On a $2 million industrial building in a typical 6b tax code, the bill goes from about $62,000 a year at 10% to about $155,100 at 25%, using tax year 2024 rates.
Quick Answer
Classes 6b, 7a, 7b and 8 assess qualifying property at 10% of market value for ten years, 15% in year 11 and 20% in year 12, then 25%. They can be renewed for another ten years, any number of times, if the owner files a renewal application with a new municipal resolution between the last 10% year and the end of year 12. Miss that window and the assessment level steps to 25%, two and a half times the incentive level. Since June 1, 2026, new commercial applicants file as 7b regardless of project cost.
The classes and their levels
| Class | Use | Level and term | Renewal |
|---|---|---|---|
| 6b | Industrial: new, rehabbed or reoccupied | 10% for 10 years, 15% year 11, 20% year 12 | Unlimited 10-year renewals |
| 6b (SER or CEERM programs) | Industrial retention | 10% for 12 years | Not renewable |
| 7a | Commercial, under $2 million in costs | 10% for 10 years, 15%, 20% | Existing grants renew in years 10 to 12; closed to new applicants after June 1, 2026 |
| 7b | Commercial in areas needing development | 10% for 10 years, 15%, 20% | Unlimited 10-year renewals |
| 7c (CURE) | Commercial urban relief | 10% for 3 years, 15% year 4, 20% year 5 | One renewal, from year 3 to the end of year 5 |
| 7d | Grocery stores in food deserts | 10% for 10 years, then 15%, 20% | One 10-year renewal |
| 8 | Commercial or industrial in areas needing revitalization | 10% for 10 years, 15%, 20% | Unlimited 10-year renewals |
| C | Remediated contaminated sites | 10% for 10 years, 15%, 20% | Industrial renewable; commercial not |
| L | Landmarks | 10% for 10 years, 15%, 20% | Renewable if first classed 3, 4 or 5b |
| 9 | Affordable rental housing | 10% for 10 years | 10-year renewals; apply 12 months before expiry |
Without an incentive, commercial and industrial property is assessed at 25%. Apartments of seven or more units are assessed at 10%, the same level as Class 9, so a Class 9 lapse does not change the level the way a 6b or 8 lapse does. The Assessor's class list has no Class 10.
What renewal takes for 6b, 7b and 8
- The window. It opens in the last year at 10% and closes when the incentive expires at the end of year 12.
- Tell the Assessor first. Notify the Assessor's Office of the intent to renew when asking the municipality for a resolution.
- The resolution. The municipality, or the County Board for unincorporated land, must adopt a resolution supporting the renewal and finding that the property's use is necessary and beneficial to the local economy.
- The filing. File the renewal application and a certified copy of the resolution with the Assessor. The Assessor's form lists a filing fee.
- County notice. The Assessor forwards the request to the County Board.
Municipal councils meet on their own calendars. Start step 3 early in year 10, not late in year 12.
Three dates to watch
June 1, 2026: ordinance changes. The County Board approved an amendment to the classification ordinance on April 16, 2026, effective June 1, 2026. New commercial projects now apply as 7b whatever their cost. Resolutions supporting an incentive must now state that the applicant filed a prevailing wage affidavit and whether a redevelopment agreement exists.
Assessment year 2027: affidavits return. The County has waived the triennial incentive affidavits since 2017. The amended ordinance extends the waiver through 2026 and lifts it at the start of the 2027 assessment year. The Assessor's bulletins say it mails affidavits at each property's triennial reassessment and that a recipient who misses the three-week return deadline loses the incentive. The City of Chicago is reassessed in tax year 2027.
December 31, 2027: the sunset clause. The ordinance says its incentive provisions for 6b, C, 7a, 7b and 8 expire on that date unless the County acts. Grants made on or before December 31, 2025 keep the terms in effect before 2026. Watch the County Board's 2027 agenda before filing renewals that fall near that date.
What a missed renewal costs
A Cook tax bill is assessed value times the state multiplier times the local tax rate. Illustration: a $2,000,000 industrial building, the tax year 2024 multiplier of 3.0355 (bills paid in 2025), and a 10.219% tax rate, the median for class 6 parcels that year. Value, multiplier and rate are held flat.
| Year | Level | Assessed value | Taxable value | Tax |
|---|---|---|---|---|
| 1 to 10 | 10% | $200,000 | $607,100 | $62,040 |
| 11 | 15% | $300,000 | $910,650 | $93,059 |
| 12 | 20% | $400,000 | $1,214,200 | $124,079 |
| 13 on | 25% | $500,000 | $1,517,750 | $155,099 |
A renewal filed in year 10 keeps the bill near $62,040 for another ten years. Without it, the client pays $31,020 more in year 11, $62,040 more in year 12 and $93,059 more each year after. Over the ten years a renewal would have covered, that is about $837,500.
Class 8 parcels sit in higher-rate tax codes. Their median rate in tax year 2024 was 20.147%, so the same building would pay about $183,500 more a year at 25%.
The record
| Tax year 2026 parcels | Year 11 (15%) | Year 12 (20%) | |
|---|---|---|---|
| Class 6 | 2,308 | 238 | 161 |
| Class 7 | 362 | 34 | 63 |
| Class 8 | 1,906 | 107 | 43 |
| Total | 4,576 | 379 | 267 |
Class 9 had 896 parcels in tax year 2026, with no step-up years.
What happened to year-12 parcels the next year:
- 2023 to 2024: 95 parcels; 79 to ordinary classes, 14 back at 10%.
- 2024 to 2025: 215 parcels; 189 to ordinary classes, 20 back at 10%.
- 2025 to 2026: 230 parcels; 205 to ordinary classes, 20 back at 10%.
Paperwork also stops incentives before they start. In tax years 2023 through 2025, the Assessor closed 692 PIN appeals with no change because the documents needed to apply an incentive were missing.
So what. Some lapses are a choice: the use changed, or the owner sold. But a firm with incentive clients should know which ones are in years 10 to 12 and whether the resolution is on a council agenda.
Where Censum fits
Docket does not track incentive renewal dates. Its research view gives a first read on any Cook PIN, and its portfolio scan scores a whole client book at once. Censum does not file appeals or renewals, is not a law firm and never takes a share of legal fees. The attorney makes every legal judgment.
The numbers behind this article
Parcel counts come from the Cook County Assessor's Parcel Universe (open data, nj4t-kc8j), tax years 2023 to 2026, major classes 6 to 9, accessed November 11, 2026. The parcel universe adds an A or B to the class code in the two step-up years; in the class histories we checked, parcels ran from a base code to A, then B, then a class 5 code, and assessed values rose by about the 15/10, 20/15 and 25/20 ratios. "Back at 10%" means a year-12 (B) parcel carried a base incentive code the next year; "ordinary classes" means a class 5 code. The 692 appeals are PIN-level Assessor Appeals rows (y282-6ig3), tax years 2023 to 2025, with reason code 44A in any reason field. The multiplier and median tax code rates come from PTAXSIM, the Cook County Assessor's Office research database (tax year 2024, the latest it holds); the Assessor says PTAXSIM results are not official. Medians are across class 6 and class 8 PINs, using each PIN's composite tax code rate.
FAQ
When can a 6b, 7b or 8 incentive be renewed?
From the last year at 10% through the end of year 12, with a renewal application and a new municipal or County Board resolution.
Can an existing 7a still renew?
Yes. The 2026 amendment lets existing 7a grants renew from year 10 to the end of year 12. New commercial applicants now file as 7b.
What happens if the renewal is late?
The level steps to 15% in year 11 and 20% in year 12, then the parcel returns to its ordinary class at 25%.
Are triennial affidavits back?
The ordinance lifts the waiver at the start of the 2027 assessment year. Watch for the Assessor's mailing at each reassessment.
Does the 2027 sunset end existing incentives?
The ordinance says the 6b, C, 7a, 7b and 8 provisions expire December 31, 2027 unless the County acts, and that earlier grants keep their prior terms. Follow County Board action.
Does Censum file renewals?
No. Censum LLC is a data and software company. The attorney files and makes every legal judgment.
Sources
- Cook County Assessor: Incentives and Special Properties
- Assessor eligibility bulletins: 6b, 7a, 7b, 7c, 7d, 8, 9, C, L
- Assessor Class 6b/7/8 Renewal Application
- Assessor definitions for the classifications of real property (revised December 16, 2024)
- Cook County Board ordinance amendment 26-0936, full text, approved April 16, 2026, effective June 1, 2026 (Cook County Code Secs. 74-63, 74-68, 74-75)
- Cook County property tax incentives
- CMAP and UIC, Cook County incentive classification report, December 2025
- Cook County Assessor: How Commercial Properties are Valued
- Cook County Assessor Parcel Universe and Assessor Appeals, Cook County open data
- PTAXSIM, Cook County Assessor's Office
Sources accessed November 11, 2026.
Next step
Pull every incentive-class PIN in your book, mark its year in the term, and start with a first read in Docket. See Censum Docket
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.