Below is more information about the Assessor's Office changes to property assessments, appeals, and operations, as well as ways Cook County is responding to COVID-19. Read more about:

Which property types are receiving a COVID-19 adjustment.

Whether your property value will go down compared to a previous year.

When property owners will be notified of their property’s COVID-adjusted value.

Why the Office determined adjustments were necessary.

2020 assessments affect 2021 property tax bills.

Data the Office used to make changes to residential values.

Data the Office used to make changes to commercial values.

Decreases in assessed value don't necessarily produce decreases in property tax bills.

Ways Cook County is providing property tax relief.

Summary of the Office's changes to operations since the onset of COVID-19.


Is everyone getting a COVID19 adjustment to their property’s value?

Our plan is that all homes in Cook County will receive COVID19 adjustments to property values, based on our Data Science team’s estimates of local changes in unemployment. Areas with larger increases in unemployment will see larger adjustments. 

Commercial properties will receive adjustments based on estimated effects on property use types, which range from no effect (for example, grocery stores) to large effects (hotels). Values of vacant land will not be adjusted for COVID19 effects.

Our first report describes adjustments in the south and west suburbs, which were scheduled for a 2020 reassessment (last reassessed in 2017). 

Our second report describes adjustments in Chicago and the North Suburbs.


I’m in the south and west suburbs. Does this guarantee my property’s assessment will go down compared to my last reassessment?

Not necessarily. Our estimate of your property’s value in 2020 also depends on your local real estate market. In the south and west suburbs, since the last 2017 reassessment, property values have changed.

Reassessments in 2020 will factor in changes in property values from 2017 to the end of 2019, and a COVID19 Adjustment for economic impacts of COVID through April 2020. 

Pre-COVID market values, and a COVID adjustment, are combined to produce 2020 fair market values.

In places like Berwyn, sale prices of homes have increased. Therefore an individual home’s value estimated by the CCAO in 2020 will reflect those upward sales trends, and a decrease from a COVID19 adjustment.

In other places, sale prices of homes have not increased. The values of these homes will reflect those flat sales trends, and a decrease from a COVID19 adjustment.

We are committed to transparency and have released township reports for reassessments in the south and west suburbs that detail changes in the real estate market as well as COVID19 Adjustments. See


When will I know my property’s COVID-adjusted value?

The CCAO has certified its reassessment work in the south and west suburbs, and incorporated applicable COVID-19 adjustments to assessed values throughout Cook County.

CCAO certified-final values for 2020 include any applicable COVID adjustment. After certification, these final values were published on the CCAO website, and a letter was mailed to the property’s owner.

To view a property’s Assessor-finalized value online:

1. Find property by PIN or address at
2. The “Assessed Valuation” section contains the CCAO Certified Final 2020 Valuation. It incorporates any reductions resulting from any appeal and COVID Adjustment.


Why did the Office determine adjustments were necessary?

Economic and market effects that have corresponding effects on real property values, including, but not limited to:

  • A record-breaking number of unemployment claims in Illinois
  • Significant downturns in some (but not all) commercial sectors
  • Widespread loss of rental income, both commercial and residential
  • Disaster declarations encompassing Cook County were issued at the federal, state, and county levels 

To not account for these changes in the south and west suburban reassessment, and depend solely on appeals, would create an inequitable result, shifting the tax burden to those who do not appeal. To examine their effects in the South Suburbs, but not the North and Chicago, would similarly shift the overall county burden onto those areas creating another form of inequity.


Will this affect my tax bill this year?

No. 2020 changes to property values will impact tax bills issued in summer of 2021.

What data did the Office use to make changes to residential values?

We estimated neighborhood increases in unemployment. These local increases in unemployment were used to determine COVID19 Adjustments (the median adjustment was 10%). Neighborhoods with larger increases in unemployment had larger adjustments.

This analysis of the economic effects of COVID-19 included sources like the Urban Institute, Case-Shiller housing indices, Real Estate Investment Trusts (REITs), and census workforce data. You can see samples of this data at

All of the data and code used to come up with these values is publicly available online here. We will also have township-level reports for residential and commercial values for each of the South Suburban townships. 


What data did the Office use to make changes to commercial values?

In addition to examining commercial REITs (see the full report for additional data), we saw data that indicated more stringent real estate lending standards will limit real estate values overall. Additional factors that called for an adjustment to values including the following:

  • Apartment rent collections are expected to be lower for April and May than historical levels.  
  • Retail rent collections for March, April, and May will be significantly lower than historical levels. 
  • Hotel occupancy rates will collapse, hitting convention hotels especially hard. 
  • Restaurants and public entertainment venues will be under pressure for an extended period of time.

Pages 11-13 of our report provide further detail on the above.


If my property’s assessed value decreases, will my property tax bill decrease?

Not necessarily. The assessed value of your property is only one factor in determining your property taxes. Your total tax levy, set by local taxing bodies like schools, is an important factor in setting your tax rate. 

Your property’s assessed value, tax rate, and exemptions will be used to calculate the second installment of the property tax bill you receive the following year. Property tax bills are sent by the Cook County Treasurer.


What are the ways Cook County is providing property tax relief?

The County’s property tax offices recently announced the deferral of late fees and penalties until October 1st. While taxes from the 2020 second installment tax bill (which reflect 2019 assessments) are due August 3rd, no late fees or penalties will be assessed until October 1st. Read more about this here.

The Cook County Treasurer postponed the County’s annual tax sale indefinitely. Read more about that announcement here. Furthermore, a new law provides additional time extensions: taxpayers now have 13 months (extended from nine months) to pay delinquent Cook County property taxes before their properties are offered to investors on a tax sale.


Summary of the Office's changes to operations since the onset of COVID-19.

Please note the following recent changes to office operations and appeals:

  • Online appeals can be filed for all property types.
  • Online filings for Certificates of Error for Exemptions are available for tax year 2016, 2017, and 2018. 
  • Taxpayers have 35 days to file an appeal. (A decrease from 40 days earlier in 2020.) 
  • The process of re-review has also been suspended. 
  • Practitioners filing appeals must file online.
  • The Office’s field staff are still out in the community to confirm physical details of properties when necessary. (Note: Assessor’s Office staff will never ask to enter your home unplanned).


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