The American Community Survey (ACS) is a new nationwide survey designed to provide communities a fresh look at how they are changing. It is a critical element in the Census Bureau's reengineered decennial census program. The ACS collects information such as age, race, income, commute time to work, home value, veteran status, and other important data.

In 2009 two types of estimates are available from the American Community Survey: 1-year estimates, which Is based on data collected in a single year (between January 2007 and December 2007) and 3-year estimates based on data collected in three consecutive years (between January 2005 and December 2007).

In 2008, the Census Bureau released its first 3-year estimates based on ACS data collected from 2005 through 2007 available annually for geographic areas with a population of 20,000 or more, including the nation, all states and the District of Columbia, all congressional districts, approximately 1,800 counties, and 900 metropolitan and micropolitan statistical areas, among others. The 2005-2007 ACS three-year estimates represent the average characteristics Over the 3-year period of time, have larger sample size than the 1-year estimates, and are less current than the 1-year estimates.

The ACS collects and produces population and housing information every year instead of every ten years. Collecting data every year provides more up-to-date information throughout the decade about the U.S. population at the local community level. About three million housing unit addresses are selected annually, from across every county in the nation.