University of Illinois Urbana‑Champaign

Geographic Region: ZIP codes

A ZIP Code Tabulation Area (ZCTA) is a geographic area used by the U.S. Census Bureau. ZCTAs change every 10 years.

ZCTAs are artificial areas created by the Census Bureau using census blocks. ZCTAs are roughly similar to the geographic areas of postal ZIP codes, which are based on delivery routes, not geographic areas.

Data available on IECAM

IECAM presents early care and education site-based data (PFA, Head Start, child care) and demographic data (population, poverty) by ZCTAs. A new set of ZCTA boundaries are released by the Census Bureau every 10 years. On the IECAM database, data for 2010 through 2020 are based on the 2010 ZCTAs. Data for 2021 and later are based on the 2020 ZCTAs. Source of definition: U.S. Census Bureau, Geography Division. Geographic Terms and Concepts – ZIP Code Tabulation Areas

Non-site-based service data (e.g., home visiting, early intervention) are not presented by ZIP code.

Change in available ZIP code data

Until August 2024, IECAM provided data by both postal ZIP code and ZCTAs. However, providing two types of ZIP codes was often confusing to users, and at times searches for service data would come up with different results for the same ZIP code (postal and ZCTA). Because of this, IECAM stopped providing data by postal ZIP codes.

ZIP Codes ZCTA (post-2020 Census)