This is the data set of residential sales used by the Cook County Assessor in their Computer Assisted Mass Appraisal system used to assess residential property values. This data set contains property information for every arm's-length residential sale in Cook County where class is within a specified list of classes. For disclaimers, see data set narrative at https://datacatalog.cookcountyil.gov/stories/s/p2kt-hk36 This data set was replaced by the more comprehensive data set Cook County Assessor's Sales.

Real estate sales data used by the Cook County Assessor to estimate Fair Cash Values for the purpose of property taxation. Deeds that include multiple PIN numbers are excluded from this data. This data is produced by joining sales data from the Illinois Department of Revenue against incomplete sales data from the Cook County Recorder of Deeds, parsing the resulting data to obtain data unique by deed number, and, in some cases, determining arms' length status of sales.

Assessment dataset used by the Cook County Assessor in their Computer Assisted Mass Appraisal (CAMA) system used to assess residential properties in Northern Triennial Townships. This dataset contains property information for every residential PIN in the northern triennial townships where class is within a specified list of classes. For disclaimers, see dataset narrative at https://datacatalog.cookcountyil.gov/stories/s/p2kt-hk36

As of February 14, 2020 this dataset will be considered archived information and will no longer be updated. First-pass property values as assessed by the Cook County Assessor in their Computer Assisted Mass Appraisal system used to assess residential properties. This dataset contains first pass values for 2019 and corresponds with residential PINs in the Cook County Assessor's Assessment Data. These are NOT final assessed values. For Disclaimers, see dataset narrative at https://datacatalog.cookcountyil.gov/stories/s/p2kt-hk36

Every assessed value in Cook County 2010 to 2020, and appeal indicators. Each PIN has three stages of assessments each year: CCAO Mailed, CCAO Certified, and Board of Review (BOR) Certified final values. This allows comparison in assessments across agencies.

Land, building, and total assessed values for all Cook County parcels, from 1999 to present. The Assessor's Office uses these values for reporting, evaluating assessment performance over time, and research. When working with Parcel Index Numbers (PINs) make sure to zero-pad them to 14 digits. Some datasets may lose leading zeros for PINs when downloaded. This data is parcel-level. Each row contains the assessed values for a single PIN for a single year. Important notes:,

This data displays total exempt EAV and total exemptions by tax code. Since residential exemptions reveal sensitive information about individual taxpayers and households, we have applied the p% statistical disclosure rule in suppressing fields.

Homeowner Exceptions by Town Number/Township in Tax Year 2010.

Commercial valuation data collected and maintained by the Cook County Assessor's Office, from 2021 to present. The office uses this data primarily for valuation and reporting. This dataset consolidates the individual Excel workbooks available on the Assessor's website into a single shared format. Properties are valued using similar valuation methods within each model group, per township, per year (in the year the township is reassessed). This dataset has been cleaned minimally, only enough to fit the source Excel workbooks together - because models are updated for each township in the year it is reassessed, users should expect inconsistencies within columns across time and townships. When working with Parcel Index Numbers (PINs) make sure to zero-pad them to 14 digits. Some datasets may lose leading zeros for PINs when downloaded. This data is property-level. Each 14-digit key PIN represents one commercial property. Commercial properties can and often do encompass multiple PINs. Additional notes:

Assessment Appeals by Town and Class from Tax Year 2010.