The U.S. Census Bureau’s American Community Survey (ACS), launched in 2005, was designed to keep pace with the nation’s increasing demand for timely and relevant data about the U.S. population and housing characteristics.

Today, the release of the 2015-2019 ACS 5-year estimates marks an important milestone. We now have three sets of 5-year estimates (2005-2009, 2010-2014, and 2015-2019) that do not overlap, which provide even more data for examining trends at the local level.

This is another step in fulfilling the vision for the ACS to provide government, businesses and the general public with more frequent data than the once-a-decade decennial census.

The ACS is an annual survey of about 3.5 million addresses that provides the United States and Puerto Rico with critical information on a wide range of over 40 topics every year.

The ACS data cover social, economic, housing and demographic characteristics. They allow federal and state government, businesses, researchers, communities and others to understand changes in specific geographies and population groups.

That, in turn, helps them plan for the future using current, reliable, and comparable data.

On their own, each set of ACS 5-year estimates is a valuable tool for comparing differences between geographies and population groups.

Comparing 5-year estimates over time is a little trickier. Consecutive 5-year estimates contain four years of overlapping coverage, so data users may not see much change between them. For example, 2014-2018 and 2015-2019 ACS 5-year estimates share sample data from 2015 through 2018.

Data users are encouraged to compare 5-year ACS data over time based on nonoverlapping estimates. Today’s release expands the nonoverlapping data available for analyzing trends for smaller geographies and population groups.

Users can now explore trends and analyze patterns with new data visualizations that highlight race and Hispanic origin data at the county level over the nonoverlapping 5-year ACS releases. They focus on three topics: education, poverty and income.

Over the next five years, it will be possible to compare three sets of nonoverlapping data each year.

Next year, for example, data users will be able to compare the 5-year estimates from 2006-2010, 2011-2015, and 2016-2020. The following year, they will be able to compare 2007-2011, 2012-2016, and 2017-2021, and so on.

This will continue until the ACS is able to release four nonoverlapping 5-year periods in 2025. The ability to analyze data clearly over time is particularly helpful for researchers examining trends.

To learn more about the ACS and connect with other ACS data users, join the ACS Data Users Group and online community. You can share messages, materials and announcements related to the ACS.  Membership is free and open to all interested ACS data users.

Nicole Scanniello is the assistant division chief for program management and communications in the U.S. Census Bureau's American Community Survey Office.