Guide
Is a ZIP Code the Same as a ZCTA?
Not quite. A ZIP code is a Postal Service routing code for a set of delivery addresses; a ZIP Code Tabulation Area (ZCTA) is the area the Census Bureau draws around the census blocks whose addresses mostly use that code. There are 33,774 ZCTAs (2020) in the 50 states, D.C. and Puerto Rico (33,791 with the island areas' 17), against 41,706 ZIP codes in the PlainZIP index.
Published October 9, 2026 by PlainZIP · written with AI tools from PlainZIP's database · figures passed the automated checks on October 9, 2026 · method
Why the difference matters
Every Census figure "by ZIP code" (population, income, home values) is published for ZCTAs. A ZIP code that has no residential addresses (PO boxes, a single organization) has no ZCTA and no Census figures. A ZCTA's edges follow census blocks, so they can differ slightly from the routes a carrier walks, and the Bureau redraws ZCTAs each decade: only 19,304 of the 2020 ZCTAs keep at least 90% of the land of the 2010 area with the same code.
PlainZIP shows each residential ZIP code's figures for its ZCTA, and compares the 2015-2019 and 2020-2024 surveys only where the area held.
Source: U.S. Census Bureau, 2020 ZCTAs and the 2010-2020 ZCTA relationship file.