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.