American Community Survey (ACS)

ACS-Summary File (SF) Technical Documentation

Below is the ACS-SF initial specification, which provides an overview of the concepts used in the development of the initial prototype of the ACS-SF.

ACS Initial Summary File Specification [PDF 53k]

Below is a 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", is a guide to the ACS-SF and the documentation. New users should review this chapter before using the ACS-SF. All documentation should be reviewed before accessing the files on the FTP site.

ACS 2007 Summary File: Technical Documentation (Production) [PDF 1167k]
ACS 2006 Summary File: Technical Documentation (Production) [PDF 1168k]
ACS 2005 Summary File: Technical Documentation (Prototype) [PDF 775k]

Below is an example of how to access an estimate and its corresponding margin of error for a specific geographic area.

ACS 2007 SF Worked Example (Production) [PDF 29k]
ACS 2006 SF Worked Example (Production) [PDF 34k]
ACS 2005 SF Worked Example [PDF 16k]

We encourage data users to assist us in improving the design and future implementation of the ACS-SF. Please send comments and/or questions on this production version and the documentation via email to: nicholas.m.spanos@census.gov.

Throughout 2008-2009 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.

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