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 firstname.lastname@example.org and title your message “ACS Summary File Feedback.” We appreciate hearing about what you like or what we can improve.
The 2021 data release is the final release of the original Sequence-Based Format; it is available for years 2005 through 2021. More information, including data, instructions and example programs are located on the ACS Summary File Sequence-Based Format page. Starting with the 2022 data release, the Table-Based Format will be the only format available.
The Table-Based ACS Summary File contains three file types:
Table Labels - Description of each line item in a table for 1-year or 5-year data release
Example File Name: ACS20211YR_Table_Shells.txt or ACS20215YR_Table_Shells.txt
Example: B01001_003 = “SEX BY AGE - Total Males Under 5 Years”
Geography Labels - All geography labels for 1-year or 5-year data release
Example File Name: Geos20211YR.txt or Geos20215YR.txt
Example: 0400000US06 = “California”
Data Files - Data (including estimates, margins of error, and geographies) organized by table ID for 1-year or 5-year release
Folder: 1YRData, 5YRData
Example: The file acsdt1y2021-b01001.dat, variable B01001_E003 for 0400000US06 = 1,129,355
There are a variety of resources available for understanding and using the table-based format. Linked below are webinars related to the table-based format, link to the FTP site to access data and documentation, instructions using geography files with the summary file, and links to the ACS Summary File GitHub page offering further guidance on the table-based format as well as examples for using SAS and Python.
2021-Present: select the Data folder to find table-based format. 2018-2020: select the Prototype folder to find table-based format.
Visit the ACS Summary File GitHub wiki page for notes on data, geography, variable changes, example code, and other important general information about the table-based format.
Visit the ACS Summary File GitHub repository for examples using SAS and Python. Additionally, there are instructions for using the ACS Summary File with Excel.