Walsh, Elliot
Hest, Robert
Stewart, Andrea

Survey Data Season Essentials: ACS vs CPS: What Is the Difference Between These Two Federal Surveys?

This post is a part of our Survey Data Season series where we examine data from various surveys that are released annually from the summer through early fall. Find all of the Survey Data Season series posts on our Survey Data Season 2024 page here.

Each year, SHADAC covers the data releases of multiple federal surveys from a variety of agencies, beginning with the National Health Interview Survey (NHIS) in June continuing through the release of Current Population Survey Annual Social and Economic Supplement (CPS ASEC) and American Community Survey (ACS) data products in September through January.

Recently, survey data from both the 2024 Current Population Survey Annual Social and Economic Supplement and the 2023 American Community Survey were released. While these two surveys overlap in a number of topics and similarities, they are also distinct in what they measure and how. 

In this blog, we will discuss the similarities and differences between two of the biggest federal survey resources available: the ACS and the CPS ASEC.

Which Federal Agencies Conduct the CPS and the ACS?

The United States Census Bureau has conducted the Current Population Survey Annual Social and Economic Supplement (CPS ASEC) since 1947 and the current iteration of the American Community Survey (ACS) since 2005 (though Census has conducted similar, prototype ACS surveys since 2000).

The Current Population Survey is jointly sponsored by the Census Bureau and the U.S. Bureau of Labor Statistics (BLS).

When Are CPS and ACS Data Released?

Single-year data from the two surveys is released annually in the second week of September, with supplemental materials for the ACS - such as the Public Use Microdata Sample or “PUMS” files, and the 5-year combined estimates - released later in the year. 

Find the survey data release schedules for these and other survey data resources on our Survey Data Season page. 

Can You Combine or Compare Multiple Years of ACS or CPS Data?

Yes - you can combine and/or compare multiple years of ACS data*. Along with 1-year ACS data files released in September, the Census Bureau has also released 5-year ACS data files annually in December since 2009.

Yes - you can generally combine and/or compare multiple years of CPS data. Care should be taken in combining or comparing across CPS data years, as the survey methodology has been revised numerous times throughout its history. Additionally, because some of the same individuals are surveyed across two CPS data years, researchers should think carefully about how to treat those repeated observations.

On SHADAC’s online data tool, State Health Compare, multiple measures utilize ACS or CPS data that allow users to compare years, trends, and more. We will go over some specific examples of how we use ACS and CPS data later in this blog.

*Except 2020 data, for which the COVID-19 pandemic majorly impacted data collection and distribution efforts. These data are considered “experimental only” and should not be compared to or combined with other years of data. However, the Census Bureau notes that the 5-year files that have the 2020 data year within them are okay for normal use.

Design Differences Between the CPS and the ACS

While both of these surveys are conducted by the Census Bureau, they differ in design, methods, measures, and more. The table below provides an overview of some of the most major differences.

*Geographic level available for data breakdowns - i.e., CPS data is available for the U.S., by region (Midwest, South, Northeast, West) and for states. 

^In-person (ACS & CPS) and mailing activities (ACS) were halted in March 2020. Both resumed in limited capacity in July 2020, and in-person activities resumed fully in September 2020 while mailing activities resumed fully in April 2021.

✝ 2020 data are experimental release only and should not be compared to other years of data.

What Do the ACS vs CPS Measure?

Both the ACS and the CPS gather information on a wide variety of measures.

According to its page on the Census Bureau website, the Current Population Survey, “[provides] information on many of the things that define us as individuals and as a society – our work, our earnings, and our education. In addition to being the primary source of monthly labor force statistics, the CPS is used to collect data for a variety of other studies that keep the nation informed of the economic and social well-being of its people.” 

Specifically, the CPS collects data on measures like:

• Health insurance coverage
• Unemployment
• Labor force participation rate
• Employment data (occupation, industry, class of worker)
• Employment-population ratio
• Child support
• School enrollment
• Demographic data collection (age, race, sex, gender, etc.)

According to its page on the Census Bureau website, the American Community Survey, “helps local officials, community leaders, and businesses understand the changes taking place in their communities. It is the premier source for detailed population and housing information about our nation.”

Specifically, the ACS collects data on measures like:

• Health insurance coverage
• Jobs and occupations
• Educational attainment
• Information on veterans
• Whether people own or rent their homes
• Employment status 
• Disability information
• Housing costs 
• Demographic data collection (age, race, sex, gender, etc.)

You can learn more about the specific questions & measures on the American Community Survey, and why they are asked, on the “Why We Ask Each Question” page on the Census Bureau website.

As you can see, both surveys collect data on similar topics: housing, income, insurance coverage, demographic information, employment, education, and more. A key difference between these two sources is that the ACS provides us with both national and state-level data and estimates for these measures (in addition to lower levels of geography), while the CPS mainly focuses on national-level data.

ACS vs CPS: Guidance on When to Use Each Source 

Knowing what survey data to use depends on what you’re looking at, what measures you’re interested in, the years you’re looking at, and more. The table below guides you through common uses of ACS and CPS survey data, and when to use which source.
 

* While the ACS began in 2005, health insurance coverage questions were not added until 2008.
✝ Except 2020 data, which were “experimental” and should not be compared to other data years.

How Does SHADAC Use ACS and CPS data?

One of the main ways that SHADAC uses the data from these surveys is for our health insurance coverage estimates. These two sources are essential for how SHADAC estimates uninsurance, public insurance, and private insurance coverage rates, including providing information on health insurance coverage nationally, by state, and by demographic categories like race and ethnicity, income, age, and more.

Using the latest 2023 data released in September 2024 from each of these two surveys, SHADAC researchers created two resources explaining overall health insurance coverage estimates. Some of our main findings from these data sources this year include:

• a stable national uninsurance rate for the total U.S. population in 2023 
  • at 7.9% according to the ACS (compared to 8.0% in 2022) 
  • at 8.0% according to the CPS (compared to 7.9% in 2022)
• the rate of uninsurance among children (age 0-18) rose significantly 
  • to 5.8% in 2023 from 5.4% in 2022 according to CPS data
  • to 5.4% in 2023 from 5.1% in 2022 according to ACS data

Read the details on our findings from these two surveys at the links below:

CPS ASEC: 2023 National Health Insurance Coverage Estimates Remain Steady for Adults but Rise for Children

2023 ACS: After Two Years of Decline, Uninsured Rates Increased for Children; Public and Private Coverage Rates See Variations Across the States

SHADAC also uses the wide variety of measures and data available from these surveys on our State Health Compare tool. This online and interactive data tool allows users to create customized data sets and visualizations of state-level health estimates for a number of measures under many categories, including measures on:

• Health Insurance Coverage
• Access to Care
• Cost of Care
• And more

Take a look at the measures available on our State Health Compare (SHC) site that use data from the ACS and CPS!

Measures that Use ACS Data on SHC

Click on any of these measures to explore the data on State Health Compare.

Health Insurance Coverage Type

Percent of adults with fair or poor health status

Percent of households with a broadband internet subscription

Percent of children considered to be poor (<100% FPG)

Income inequality (Gini Coefficient)

Percent of cost-burdened rental households

Measures That Use CPS Data on SHC

Click on any of these measures to explore the data on State Health Compare.

Health Insurance Coverage Type

Percent of people with a high medical cost burden

Median Medical Out-of-Pocket Spending

Percent of adults with fair or poor health status

Have you used State Health Compare to explore data and delve into health care topics? Share your work and tag us on LinkedIn - we love to see how people use SHC to make connections, identify gaps, and work towards making health care accessible & affordable for all people. You can also e-mail us at shadac@umn.edu - we would love to connect!

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