Employee payroll data for all Cook County employees excluding Forest Preserves, indicating amount of base salary paid to an employee during the County fiscal quarter. Salaries are paid to employees on a bi-weekly basis.
Any pay period that extended between quarters will be reported to the quarter of the Pay Period End Date. (e.g. If a Pay Period runs 02/21-03/05, that pay period would be reported in the Q2 period, as the end of the pay period falls in March - Q2)

The county fiscal quarters are:
Q1: December - February
Q2: March - May
Q3: June - August
Q4: September - November

The Employee Unique Identifier field is a unique number assigned to each employee for the purpose of this data set, that is not their internal employee ID number, and allows an employee to be identified in the data set over time, in case of a name change or other change. This number will be consistent within the data set, but we reserve the right to regenerate this number over time across the data set.

Employee payroll data for all Cook County employees excluding Forest Preserves, indicating amount of base salary paid to an employee during the County fiscal quarter. Salaries are paid to employees on a bi-weekly basis.
Any pay period that extended between quarters will be reported to the quarter of the Pay Period End Date. (e.g. If a Pay Period runs 02/21-03/05, that pay period would be reported in the Q2 period, as the end of the pay period falls in March - Q2)

The county fiscal quarters are:
Q1: December - February
Q2: March - May
Q3: June - August
Q4: September - November

The Employee Unique Identifier field is a unique number assigned to each employee for the purpose of this data set, that is not their internal employee ID number, and allows an employee to be identified in the data set over time, in case of a name change or other change. This number will be consistent within the data set, but we reserve the right to regenerate this number over time across the data set.

KNOWN ISSUE: Several records are missing Bureau and Office information. We are working on correcting this and will update the dataset when this issue has been resolved.

For data prior to Fiscal Year 2016, see datasets at https://datacatalog.cookcountyil.gov/browse?tags=payroll

Disclaimer: This list is updated monthly on the website. If up-to-the-minute accuracy is needed, contact us at 312-603-6328. This dataset contains businesses registered for Wholesale Tobacco Dealers.

This dataset contains descriptions of unidentified remains whose cases have been processed by the Medical Examiner’s Office.

Call 312-666-0500 to speak to Deputy Chief Investigator, Earl Briggs, about matching one of these unidentified bodies to the identity of a missing person. Descriptions of cases can also be found at NAMUS.gov

Please note that images posted in this section may be graphic in nature and may not be appropriate for all users.

This dataset provides the list of vendors and contracts to be executed by the Office of the Chief Procurement Officer and is updated 3 days before award.

M/W/DBE Participation Types
MBE = Minority Business Enterprise
WBE = Women Business Enterprise
DBE = Disadvantaged Business Enterprise
Native American (4)
African American (5)
Female (7)
Asian (8)
Hispanic (9)

A complete, historic universe of Cook County parcels with attached geographic, governmental, and spatial data.

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.

Additional notes:

• Non-taxing district data is attached via spatial join (st_contains) to each parcel's centroid.


• Tax district data (school district, park district, municipality, etc.) are attached by a parcel's assigned tax code.


• Centroids are based on Cook County parcel shapefiles.


• Older properties may be missing coordinates and thus also missing attached spatial data (usually they are missing a parcel boundary in the shapefile).


• Newer properties may be missing a mailing or property address, as they need to be assigned one by the postal service.


• This dataset contains data for the current tax year, which may not yet be complete or final. Assessed values for any given year are subject to change until review and certification of values by the Cook County Board of Review, though there are a few rare circumstances where values may change for the current or past years after that.


• Rowcount for a given year is final once the Assessor has certified the assessment roll all townships.


• Data will be updated monthly.


• Depending on the time of year, some third-party and internal data will be missing for the most recent year. Assessments mailed this year represent values from last year, so this isn't an issue. By the time the Data Department models values for this year, those data will have populated.


• 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.


• Due to discrepancies between the systems used by the Assessor and Clerk's offices, tax_district_code is not currently up-to-date in this table.

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.

Situs and mailing addresses of Cook County parcels. Used by the Assessor's office to mail assessment notices.

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.

Additional notes:

• Mailing addresses can be out of date or fail to properly reflect deed transfers.


• Newer properties may be missing a mailing or property address, as they need to be assigned one by the postal service.


• This dataset contains data for the current tax year, which may not yet be complete or final. Assessed values for any given year are subject to change until review and certification of values by the Cook County Board of Review, though there are a few rare circumstances where values may change for the current or past years after that.


• Rowcount for a given year is final once the Assessor has certified the assessment roll all townships.


• Data will be updated monthly.

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.

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:

• Assessed values are available in three stages: 1) mailed, these are the initial values estimated by the Assessor's Office and mailed to taxpayers. 2) certified, these are values after the Assessor's Office closes appeals. 3) Board of Review certified, these are values after the Board of Review closes appeals.


• The values in this data are assessed values, NOT market values. Assessed values must be adjusted by their level of assessment to arrive at market value. Note that levels of assessment have changed throughout the time period covered by this data set.


• This data set will be updated roughly contemporaneously (monthly) with the Assessor's website as values are mailed and certified. However, note that there may be small discrepancies between the Assessor's site and this data set, as each pulls from a slightly different system. If you find a discrepancy, please email the Data Department using the contact link below.


• This dataset contains data for the current tax year, which may not yet be complete or final. Assessed values for any given year are subject to change until review and certification of values by the Cook County Board of Review, though there are a few rare circumstances where values may change for the current or past years after that.


• Rowcount for a given year is final once the Assessor has certified the assessment roll all townships.


• 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.

This dataset provides a cumulative record of payment and invoice details for County suppliers, vendors and other payees. Data is from December 1, 2016 to present. Payment data prior to December 1, 2016 is archived in the Cook County Check Register here: https://datacatalog.cookcountyil.gov/Finance-Administration/Cook-County-Check-Register/gywr-fjeh