What are the Public Use Microdata Areas (PUMAs) in the American Community Survey (ACS) Public Use Microdata Sample (PUMS) data?

Public Use Microdata Areas (PUMAs) are non-overlapping areas that partition each state into areas containing about 100,000 residents. PUMAs were developed to be the most detailed geographic area available in the Public Use Microdata Sample (PUMS). Because the State Data Centers (SDCs) and their partner organizations help define these areas for the Census Bureau, they should be meaningful to many data users. PUMA boundaries are updated with each decennial census in cooperation with the SDCs. For more information, visit the Public Use Microdata Areas page.

Detailed maps of state PUMA boundaries are available on the Reference Maps page.