Update 10/31/2023: Sales are no longer filtered out of this data set based on deed type, sale price, or recency of sale for a given PIN with the same price. If users wish to recreate the former filtering schema they should set sale_filter_same_sale_within_365, sale_filter_less_than_10k, and sale_filter_deed_type to False.

Parcel sales for real property in Cook County, from 1999 to present. The Assessor's Office uses this data in its modeling to estimate the fair market value of unsold properties.

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.

Sale document numbers correspond to those of the Cook County Clerk, and can be used on the Clerk's website to find more information about each sale.

NOTE: These sales are filtered, but likely include non-arms-length transactions - sales less than $10,000 along with quit claims, executor deeds, beneficial interests are excluded. While the Data Department will upload what it has access to monthly, sales are reported on a lag, with many records not populating until months after their official recording date.

Current property class codes, their levels of assessment, and descriptions can be found on the Assessor's website. Note that class codes details can change across time.

For more information on the sourcing of attached data and the preparation of this dataset, see the Assessor's Standard Operating Procedures for Open Data on GitHub.

Annual salaries paid to employees by the Cook County Comptroller as of September 16, 2011. Does not include deduction for furlough or closure days for employees subject to furloughs and closures. Does not include amounts paid by other governmental entities. For 2014 salaries see https://datacatalog.cookcountyil.gov/resource/hdna-35se

Public Statements issued by the Office of the Independent Inspector General regarding matters associated with the Metropolitan Water Reclamation District of Greater Chicago.

This data contains every residential Property Index Number (PIN) and corresponding Assessed Values from significant stages in the assessment process.

This data was replaced with the more comprehensive Cook County Assessor's Fair Cash Values.

The Parcel 2016 feature contains tax parcel polygons for the 2016 property tax assessment at the County. This feature reflects tax parcel polygons as they existed from 1/1/2016 through 12/31/2016. Each parcel is uniquely identified with a Property Index Number (PIN).

Tax code rates for Tax Years 2006 through 2013. Data is updated yearly. For more information on Tax codes visit the Cook County Clerk's website at: http://www.cookcountyclerk.com/tsd/Pages/default.aspx

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.

Quit Claim Deeds recorded with the Cook County Recorder of Deeds. Data covers 2013 through March 27, 2015. This dataset will be updated Quarterly. For more information see http://cookrecorder.com/ .

The Parcel 2012 feature contains tax parcel polygons for the 2012 property tax assessment at the County. This feature reflects tax parcel polygons as they existed from 1/1/2012 through 12/31/2012. Each parcel is uniquely identified with a Property Index Number (PIN).