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.

Pursuant to Section 2-573 of the Cook County Code of Ethics, officials that hold employment outside their elected office shall disclose such employment, or any change in employment to the Ethics Director and the Board of Ethics within 30 days of engaging in such employment or change in employment. Such disclosures by officials should be posted and made publicly available on the Ethics Departments web-page.

The Parcel 2021 feature contains tax parcel polygons for the 2021 property tax assessment at the County. This feature reflects tax parcel polygons as they existed from 1/1/2021 through 12/31/2021. An ESRI Service is available at: https://hub-cookcountyil.opendata.arcgis.com/datasets/34021b4f3b834a69bf737e6c3344888e_0

As a public agency, the Office of the Chief Procurement Officer welcomes all vendors to participate in the open and competitive process. The buying plan contains hundreds of great opportunities for vendors to do business with Cook County. The buying plan includes information on numerous County projects and needs. You will find useful information on the department requesting proposals, project descriptions, value of contract, advertising date, and various Minority, Women and Veteran Business Enterprise subcontracting opportunities. OCPO encourages all potential vendors to use the information provided in the plan to assist them in future procurement efforts. Please contact Procurement staff or visit our website at https://www.cookcountyil.gov/procurement with any questions regarding procurement and contracting.

This data set contains characteristic data points used by the Cook County Assessor in the 2021 Chicago reassessment to produce initial estimates of the current market value of most Chicago homes (single-family homes, small multi-family homes, and condo units). You can use the "Filter" option to search for a property's PIN or address, and see what data the Assessor’s Office had about a home’s characteristics at the time of modeling*. To learn more about how the 2021 model used this data, read about our public Residential Automated Valuation Model here. Chicago properties not listed here are reassessed using different modeling procedures.

*Important Note: This dataset is, at the time of publication, an early snapshot of data. Data about a home might change later in the assessment process this year as Assessor’s Office staff and analysts review these properties. After this review, updated characteristics and market values are mailed to homeowners. If the data listed on the assessment notice is incorrect, an appeal can be filed to provide the correct characteristics.

As a public agency, the Office of the Chief Procurement Officer welcomes all vendors to participate in the open and competitive process. The buying plan contains hundreds of great opportunities for vendors to do business with Cook County. The buying plan includes information on numerous County projects and needs. You will find useful information on the department requesting proposals, project descriptions, value of contract, advertising date, and various Minority, Women and Veteran Business Enterprise subcontracting opportunities. OCPO encourages all potential vendors to use the information provided in the plan to assist them in future procurement efforts. Please contact Procurement staff or visit our website at https://www.cookcountyil.gov/procurement with any questions regarding procurement and contracting.

The Cook County Department of Emergency Management and Regional Security (EMRS) reminds residents to take appropriate precautions to protect themselves and their families.

Municipalities and townships across Cook County are opening warming centers for residents. Residents who do not have adequate heating in their homes are encouraged to visit a warming center to ensure they remain safe.

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.

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.

The Parcel 2020 feature contains tax parcel polygons for the 2020 property tax assessment at the County. This feature reflects tax parcel polygons as they existed from 1/1/2020 through 12/31/2020. An ESRI Service is available at: https://hub-cookcountyil.opendata.arcgis.com/datasets/577d80fcbf0441a780ecdfd9e1b6b5c2_0/explore