American Community Survey (ACS)

ACS-Summary File (SF) Technical Documentation

Here is the ACS-SF initial specification, which gives data users an overview of the concepts used in the development of the initial prototype of the ACS-SF.

ACS Initial Summary File Specification [PDF 53k]

Here is the complete set of technical documentation, which provides detailed information and reference materials on how to use the ACS-SF. Chapter 2 of this document, "How to Use the ACS Summary File", can be used as a guide for data users to the ACS-SF and the documentation. New users should review this chapter before using the ACS-SF. It is suggested that ACS-SF users first review all of the documentation before accessing the files on the FTP site.

ACS 2006 Summary File: Technical Documentation (Production) [PDF 1168k]
ACS 2005 Summary File: Technical Documentation (Prototype) [PDF 775k]

Here is an example of how to access one estimate and Margin or Error from one table for one area from the ACS summary file.

ACS 2006 SF Worked Example (Production) [PDF 34k]
ACS 2005 SF Worked Example [PDF 16k]

We encourage data users to provide comments or questions on this production version and the documentation to help us further improve the design and future implementations of the ACS-SF. Please send any comments or questions that you have via email to: nicholas.m.spanos@census.gov. Throughout 2008 we may issue updates and corrections to this production version of the ACS-SF. We will keep users aware of these updates via the ACS Alert from the ACS website and on the ACS errata page located on: http://www.census.gov/acs/www/UseData/Errata.htm.

[PDF] or denotes a file in Adobe’s Portable Document Format. To view the file, you will need the Adobe® Acrobat® Reader available free from Adobe. This symbol indicates a link to a non-government web site. Our linking to these sites does not constitute an endorsement of any products, services or the information found on them. Once you link to another site you are subject to the policies of the new site.