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ACS Summary File Sequence-Based Format
ACS Summary File Sequence-Based Format (2005-2021)
The American Community Survey (ACS) Summary File Sequence-Based Format is a set of comma-delimited text files that contain all of the Detailed Tables for the ACS data releases. Summary File data in the sequence-based format are only available for data years 2005-2021. The sequence-based format is divided into three file types: estimates, margin of error, and geography files for each release.
In the sequence-based format, Detailed Tables are stored in a series of files with only the data from the tables and without such information as the table title, description of the rows, or geographic identifiers. That information is located in other files that the user must merge with the data files to reproduce complete tables.
The handbook, Using the ACS Summary File: What Data Users Need to Know, provides an overview and more about working with the sequence-based format. Data, instructions, guides, and example SAS programs are provided below for each year.
2020 ACS 1-year Estimates (Not Available in Summary File)
Due to the impact of the COVID-19 pandemic, the Census Bureau changed the 2020 ACS release. Instead of providing the standard 1-year data products, the Census Bureau released 2020 ACS 1-year experimental estimates. There is no 2020 ACS 1-year Summary File.
2016-2020 ACS 5-year Estimates
The 2016-2020 ACS 5-year data products that report data related to Congressional Districts are based on the 116th Congress. The Census Bureau does not collect congressional district boundaries from the states during the congressional session that aligns with the decennial census (e.g., 117th). Additional explanation can be found in our geographic user note.
Templates
Includes description of variables in each column for all sequence files and for the comma delimited version (.csv) of the geography file.
Technical Documentation
The Summary File Core Technical Document is now available as What ACS Summary File Data Users Need to Know.
Appendices include the sequence number and restrictions for all tables, as well as summary levels available for each release.
Summary File User Tools
Table Shells
Contains table ID, line number, unique ID (table ID + Line Number), stub, and data release
Sequence Number/Table Number Lookup File
Contains information on the relationship between the sequences and the tables
Simplified Geography Files
Contains basic geography information, including LOGRECNO, GEOID, and name, in an Excel file with tabs for the US, as well as each state or state equivalent. Compared to the standard geography files in .csv and .txt format, these simplified files contain only the geography variables needed to read the ACS Summary File into Excel.
SAS Programs
Contains SAS programs for each sequence per state, which can be used to convert each estimate and margin of error into SAS datasets with table stubs
Detailed example SAS program containing SAS macros which access the geography, estimate and margin of error data. It creates one table for all geographies from the ACS Summary File. Segments of the SAS codes can be used to convert geography files into SAS datasets.
Page Last Revised - September 7, 2022
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