American Community Survey (ACS)

The American Community Survey (ACS) Public Use Microdata Sample (PUMS) files are a set of untabulated records about individual people or housing units. The Census Bureau produces the PUMS files so that data users can create custom tables that are not available through pretabulated (or summary) ACS data products.

The confidentiality of ACS respondents is protected through a variety of means, ensuring that it is impossible to identify individuals who provide any response, yet making sure the results are still useful. The PUMS records do not contain names, addresses, or any information that can identify a specific housing unit, group quarter, or person.

PUMS files are perfect for people, such as students, who are looking for greater accessibility to inexpensive data for research projects. Social scientists often use the PUMS for regression analysis and modeling applications.

The Census Bureau produces ACS 1-year and 5-year PUMS files. The 5-year PUMS files are multiyear combinations of the 1-year PUMS file with appropriate adjustments to the weights and inflation adjustment factors. The PUMS files are accessible via American FactFinder, the Census Bureau's FTP site, and DataFerrett. Statistical software is needed to use the PUMS files from American FactFinder and the FTP site.

Learn more about PUMS in the Compass Products What PUMS Data Users Need to Know handbook and Introduction to the PUMS training presentation. You can also learn more about creating ACS custom tables using DataFerrett by viewing Part 1 and Part 2 of our new videos.

The PUMS Technical Documentation includes the PUMS ReadMe, Subjects in the PUMS, PUMS Data Dictionary, Code Lists, PUMS Top and Bottom Coded Values, Accuracy of the PUMS, and PUMS Estimates for User Verification.

Region, Division, State, and Public Use Microdata Areas (PUMAs) are the only geographic areas identified in the ACS PUMS. Of these, Public Use Microdata Areas (PUMAs) are the most detailed geographic areas available.