ZIP Code Tabulation Areas (ZCTAs) are statistical entities developed by the
United States Census Bureau
The United States Census Bureau (USCB), officially the Bureau of the Census, is a principal agency of the U.S. Federal Statistical System, responsible for producing data about the American people and economy. The Census Bureau is part of th ...
for tabulating summary statistics. These were introduced with the
Census 2000 and continued with the 2010 Census and 5 year
American Community Survey data sets. This new entity was developed to overcome the difficulties in precisely defining the land area covered by each
ZIP code. Defining the extent of an area is necessary in order to tabulate census data for that area.
ZCTAs are generalized area representations of the
United States Postal Service
The United States Postal Service (USPS), also known as the Post Office, U.S. Mail, or Postal Service, is an independent agency of the executive branch of the United States federal government responsible for providing postal service in the ...
(USPS) ZIP code service areas, but are not the same as ZIP codes. Individual USPS ZIP codes can cross
state, place,
county
A county is a geographic region of a country used for administrative or other purposes Chambers Dictionary, L. Brookes (ed.), 2005, Chambers Harrap Publishers Ltd, Edinburgh in certain modern nations. The term is derived from the Old French ...
,
census tract,
census block group and
census block boundaries, so the Census Bureau asserts that "there is no correlation between ZIP codes and Census Bureau geography". Moreover, the USPS frequently realigns, merges, or splits ZIP codes to meet changing needs. These changes are usually not reflected in the annual
TIGER
The tiger (''Panthera tigris'') is the largest living Felidae, cat species and a member of the genus ''Panthera''. It is most recognisable for its dark vertical stripes on orange fur with a white underside. An apex predator, it primarily pr ...
releases. Each ZCTA is constructed by aggregating the
Census 2010 blocks whose
addresses use a given ZIP code. In assembling census statistical units to create ZCTAs, the Census Bureau took the ZIP code used by the majority of addresses in each census unit at the time the data was compiled. As a result, some addresses end up with a ZCTA code that is different from their ZIP code. ZCTAs are not developed for ZIP codes that comprise only a small number of addresses. Several ZCTAs represent ZIPs that no longer exist due to realignment by the USPS.
There are approximately 42,000 ZIP Codes and 32,000 ZCTAs. The reason that there is not one ZCTA for every ZIP Code is that only populated ''areas'' are included in the Census data, and thus ZIP Codes that only serve
PO Boxes have no corresponding ZCTA.
See also
*
Census-designated place
A census-designated place (CDP) is a concentration of population defined by the United States Census Bureau for statistical purposes only.
CDPs have been used in each decennial census since 1980 as the counterparts of incorporated places, suc ...
*
ZIP Code
References
External links
United States Census Bureau ZIP Code Tabulation Areas (ZCTAs)
{{ZIP Code
United States Census Bureau geography
ZIP code