The American Community Survey (ACS) Summary File is a unique data product that includes all estimates and margins of error (MOE) from the Detailed Tables for all geographies published for the ACS. The ACS Summary File allows data users to download statistics for a large number of tables and geographic areas. Currently, there are two methods for downloading the summary file: the new Table-Based Format and original Sequence-Based Format.

For the 2018 data release, the Census Bureau tested a new, Table-Based Format for the ACS Summary File. This format groups the estimates and MOE by table ID, removing the need to merge these files. That is, a file is posted for each table containing both the estimates and MOE for all available geographies. Data users only need to merge in geography labels to create complete tables.

The Table-Based Format is the recommended format for the 2021 data release, and it will be the only format starting with the 2022 data release. Check out the Getting Started and data year tabs below for information and resources. The resources include instructions for merging the geography labels with each table via Excel or programs like SAS and Python. 

To share feedback on the Table-Based Format, please send your comments to acso.users.support@census.gov and title your message “ACS Summary File Feedback.” We appreciate hearing about what you like or what we can improve.