This dataset contains address points for addresses in Cook County. An ESRI Service is available at: https://hub-cookcountyil.opendata.arcgis.com/datasets/5ec856ded93e4f85b3f6e1bc027a2472_0/ Data is updated and maintained by Cook County GIS.

About this itemThanks for your interest in our public access GIS hub site. This site brings many of our most popular mapping resources together in one place for easy access. Users can quickly find the content they need and discover other areas of interest by exploring a series of Map Galleries. For those seeking GIS data, an open data portal with a growing collection of local datasets is just a click or tap away. Author/ContributorKyle ObergOrganizationCook CountyOrg Websiteco.cook.mn.us

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.

Read about the Assessor's 2025 Open Data Refresh.

KML file of public schools located in Cook County. To view or use these files, special GIS software such as Google Earth is required.

Parcels with property tax-exempt status across all of Cook County per tax year, from Tax Year 2022 on, with geographic coordinates and addresses.

As of 2017 owner names in this dataset are no longer being regularly updated. We are trying to figure out a solution to this problem.

Properties of religious, charitable, and educational organizations, as well as units of federal, state and local governments, can be eligible for exemption from property taxes. The Illinois Department of Revenue (IDOR) ultimately grants qualified organizations with property tax exempt status, with additional administration by the Board of Review and/or Assessor. Learn more here, and see the Assessor's guidance for religious organizations here.

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:

• Parcel entroids are based on Cook County parcel shapefiles.
• Newer properties may be missing a mailing or property address, as they need to be assigned one by the postal service.
• Exempt status for parcels changes regularly depending on the use and owner of a given parcel. Please contact Assessor.Exempt@cookcountyil.gov if you need additional information about parcels excluded from this dataset.
• Data will be updated monthly.
• This dataset contains data for the current tax year, which may not yet be complete or final. Assessed values and property tax-exempt status 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.

Read about the Assessor's 2025 Open Data Refresh.

Cook County GIS Dept map of Cook County Facilities in PDF format. The map shows all public Cook County Facilities, municipalities, Cook County highway jurisdiction, Cook County Commissioner Districts, major streets, highways, and water bodies.

The purpose of this dataset is to indicate the boundary of each park in Cook County, Illinois.

Forest Preserve District of Cook County boundaries. To view or use these shapefiles, compression software and special GIS software, such as ESRI ArcGIS, is required.

Land, building, and total assessed values, pre and post-appeal with the Cook County Assessor’s office, 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 Identification 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 pre and post-appeal. Important notes:This dataset includes appeal cases that are currently open. Data for these cases is not final and is subject to change. Each row includes two stages: 1) mailed, these are the initial assessed values (AVs) estimated by the Assessor's Office and mailed to taxpayers. The columns mailed_bldg, mailed_land, and mailed_tot are the AVs for the building, land, and total, at the mailed stage. 2) certified, these are values after the Assessor's Office closes appeals. The columns certified_bldg, certified_land, and certified_tot are the AVs for the building, land, and total, after the Assessor has completed appeal decisions. Values in this dataset are not final assessed values for a given year as they are still subject to change if a taxpayer appeals to the Cook County Board of Review. At present, this dataset does not contain appeal decisions from this final third stage. However, the final stage AVs and appeal decisions can be downloaded from the Board of Review Appeal Decision History dataset. Due to the current transition from the county's legacy system to a modern system of record, appeal data is sparse prior to 2021. Values and change/no change decisions are available, but the reason, agent, and type fields will only be complete once the new system has been successfully batch updated with complete historical data. 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 monthly regardless of the Assessor's mailing and certification schedule. 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 preparation of this dataset, see the Assessor's Standard Operating Procedures for Open Data on GitHub. <a href="https://datacatalog.cookcountyil.gov/stor

Public schools located in Cook County. To view or use these shapefiles, compression software and special GIS software, such as ESRI ArcGIS, is required.

Cook County GIS Dept map of Cook County Facilities in PDF format. The map shows all public Cook County Facilities, municipalities, Cook County highway jurisdiction, Cook County Commissioner Districts, major streets, highways, and water bodies.

Municipalities around Cook County open warming centers for area residents as temperatures start to drop. Residents who need to seek shelter should contact the center first to verify it is open.

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.

Read about the Assessor's 2025 Open Data Refresh.

Cook County Department of Public Health Suburban Cook County District boundaries. This dataset contains municipal and township boundaries for Suburban Cook County with attributes designating what CCDPH district the area is in. The names in the "DISTRICT" field can be used to join with other Public Health Open Datasets on this portal. The "CCDPHJURIS" field states whether the area is part of CCDPH Jurisdiction.

Cook County 10-digit parcels with attached distances to various spatial features.

When working with 10-digit Parcel Index Numbers (PINs) make sure to zero-pad them to 10 digits. Some datasets may lose leading zeros for PINs when downloaded. 10-digit PINs do not identify individual condominium units.

Additional notes:

• 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).
• Attached spatial data does NOT all go back to 2000. It is only available for more recent years, primarily those after 2012.
• 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 annually as new parcel shapefiles are made available.

Read about the Assessor's 2025 Open Data Refresh.

This data is compiled by the Cook County Department of Public Health using data from the Illinois Department of Public Health Vital Statistics. It includes the annual number of deaths, crude and age-adjusted death rates by selected causes of death. Further analysis is available by age group, race/ethnicity, gender and decedent's place of residence in suburban Cook County at the time of their death. Note: Counts suppressed for events between 1 and 4, Rates not calculated for events less than 20

Municipalities around Cook County have opened cooling centers for area residents as temperatures start to rise. Residents who need to seek shelter should contact the center first to verify it is open. This dataset will be no longer updated on May 1, 2019. Please refer to this link for future updates: https://datacatalog.cookcountyil.gov/dataset/Cook-County-Cooling-Centers-Map/dnn9-esge

The Public Land Survey System (PLSS) is the way land in the United States is subdivided, it forms the foundation of Cook County's cadastral system for identifying and locating land records. Tax parcels are identified using township and section notation, in a modified format. The PLSS serves as a way for users to navigate the parcel geodatabase. This PLSS feature data set is intended to correspond to tax pages on the Cook County Tax Maps. They should not be used for measurement or surveyor purposes. In addition, the parcel attributes PINA (area/township) and PINSA (subarea/section) do not necessarily correspond to the PLSS township and section polygon in which a given parcel resides. The PLSS data is modeled as a single composite network coverage that encompasses townships (area), sections (subarea), quarter sections, and half quarter section. Tax map pages, which typically correspond to half quarter sections (in an east-west split), are modeled as a region subclass in the LANDFABRIC layer. If an indigenous people's reserve was present on the tax map, it was digitized to create subpolygons of the half-quarter section, and those polygons were attributed with the name of the reserve. Within this PLSS data set, a half-quarter section is the smallest polygon unit, except in cases where an Indigenous People's Reserve line is present. The cadastral data for Cook County have previously not been digital nor automated. This project is the initial automation for this information. This database was designed to represent a continuous, non-overlapping spatial database accounting for all land area in Cook County.The PLSS is updated as needed.

The Public Land Survey System (PLSS) is the way land in the United States is subdivided, it forms the foundation of Cook County's cadastral system for identifying and locating land records. Tax parcels are identified using township and section notation, in a modified format. The PLSS serves as a way for users to navigate the parcel geodatabase. This PLSS feature data set is intended to correspond to tax pages on the Cook County Tax Maps. They should not be used for measurement or surveyor purposes. In addition, the parcel attributes PINA (area/township) and PINSA (subarea/section) do not necessarily correspond to the PLSS township and section polygon in which a given parcel resides. The PLSS data is modeled as a single composite network coverage that encompasses townships (area), sections (subarea), quarter sections, and half quarter section. Tax map pages, which typically correspond to half quarter sections (in an east-west split), are modeled as a region subclass in the LANDFABRIC layer. If an indigenous people's reserve was present on the tax map, it was digitized to create subpolygons of the half-quarter section, and those polygons were attributed with the name of the reserve. Within this PLSS data set, a half-quarter section is the smallest polygon unit, except in cases where an Indigenous People's Reserve line is present. The cadastral data for Cook County have previously not been digital nor automated. This project is the initial automation for this information. This database was designed to represent a continuous, non-overlapping spatial database accounting for all land area in Cook County.The PLSS is updated as needed.

Description of Open Data available from the Cook County Assessor's Office, with assets newly published in 2025.