Cook County 2021 Property Tax Parcel Boundaries and Assessment Data

Cook County tax parcel polygons for the 2021 property tax assessment year. This dataset contains parcel boundaries and associated administrative data as recorded by the Cook County government from January 1, 2021, through December 31, 2021. It is published by datacatalog.cookcountyil.gov.

Use Cases

• Analyze spatial distribution of AssessorBLDGclass across ChicagoWard boundaries to identify zoning patterns.
• Join parcel data with external datasets using CensusTract_GEOID or PIN10 for socioeconomic studies.
• Model property tax code (TAXCODE) based on geographic features like PoliticalTownship and CommissionerDistrict.
• Map school district funding sources by aggregating parcels within UnitSchlTaxDist, HighSchlTaxDist, and ElemSchlTaxDist.

Strengths

• Parcel data covers a full calendar year (1/1/2021 to 12/31/2021).
• Includes 25 distinct columns for administrative and geographic attributes.
• Geospatial data (the_geom) provided alongside tabular attributes.

Limitations

• Unknown row count prevents assessment of sample size and granularity.
• Data is specific to 2021 and may not reflect current parcel configurations.
• No sample data available to verify data quality or null value prevalence.

Provenance

Source

datacatalog.cookcountyil.gov

Time Range

2021-01-01 to 2021-12-31

Freshness

Dataset metadata last updated January 27, 2026, but underlying data covers 2021.

Geography

Cook County, Illinois, USA