Understanding Cook County Property Assessment Notices

What is an assessment notice?

Your assessment notice will look something like the above image.

It contains your home’s Property Index Number (PIN), characteristics, updated fair market value, and updated assessed value. It also contains a list of exemptions applied to this property in the past few years.

How often is my property reassessed?

Cook County is reassessed triennially, which means one-third of the county is reassessed each year. This year, the south suburbs will be reassessed. The City of Chicago will be reassessed in 2021. The northern suburbs will be reassessed in 2022. Your property may also be reassessed if there are significant changes due to a permit application, property division, demolition, or other special application.

What is the difference between my assessment notice and my tax bill?

Your assessment notice usually arrives once every three years after your township has been reassessed. Our schedule of reassessment mailing dates can be found here along with corresponding appeal dates. It does not require any action on your part though you may appeal if you believe the assessment is too high (see below).

Your annual tax bill comes from the County Treasurer’s office in two installments: one is due in February and the other is due in August. 

Your reassessment will affect the second installment tax bill the following year. So if your assessment notice arrives in 2020, the tax bill reflecting this assessment will arrive in July of 2021. Any appeals of your assessment will be reflected in the second installment tax bill the following year.

How does the Assessor's Office value property?

We have explanations of our residential valuation and commercial valuation posted on our website. 

If I believe the information on this notice is incorrect, how do I appeal?

If the characteristics listed for your home are wrong, if you think your home is worth less than the fair market value on this notice, or if you think there is information about your home that was not taken into account, you can file an appeal of your assessment.

Appeals can be filed with our office or with the Board of Review. Please see our Appeals section for information on how and when to file an appeal with our office. Visit cookcountyboardofreview.com for information and deadlines about appeals with their office.

If my assessment increases, does that mean that my tax bill will increase?

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 tax rate, assessment, and exemptions together determine your total tax bill.

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.

We have more information available on how our property tax system works here. To learn more about and apply for exemptions that can reduce your tax bill, visit our Exemptions section.