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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.

  • 2021
  • 2020
  • 2019
  • 2018
  • 2017
  • 2016
  • 2015
  • 2014
  • 2013
  • 2012
  • 2011
  • 2010
  • 2009
  • 2008
  • 2007
  • 2006
  • 2005

2021 ACS 1-year Estimates

2017-2021 ACS 5-year Estimates


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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