As the U.S. Census Bureau gears up to release the Annual Social and Economic Supplement to the Current Population Survey (CPS ASEC) September 10 and the American Community Survey (ACS) September 12, we wanted to provide an overview of key similarities and differences between their health insurance coverage measures. Health insurance stats from these surveys are available in Census Bureau reports, public data files, Health Insurance Historical Table Series, and related products.

Both the CPS ASEC and the ACS obtain information about health insurance at the time of the survey by asking respondents if they currently have coverage through several different sources. The CPS ASEC then goes further to collect detailed information about health insurance coverage and type for the previous calendar year.  These sources can be summarized into the broad categories of private, public, or none (uninsured). The broad public category is further subdivided into Medicare, Medicaid, and Department of Veterans Affairs coverage. The broad private category is subdivided into employer-based, directly purchased, and TRICARE — the health program for active duty and National Guard and Reserve service members, retirees, and family. Historical data are available for both surveys, as far back as 1987 for the CPS ASEC and 2008 for the ACS (Table 1).

The CPS ASEC and ACS differ in several ways, including timing and mode of data collection, geographic level of estimates available, and the time periods to which the resulting health insurance estimates refer (Table 1).

American Community Survey

The ACS is based on a rolling sample of households with data collected continuously throughout the year. Its question on current health insurance coverage does not refer to a specific date or period of time other than “currently.” The resulting annual coverage estimate is based on the sum of responses collected from different individuals throughout the survey year.

Current Population Survey Annual Social and Economic Supplement

The CPS ASEC is conducted February through April each year. As with the ACS, respondents answer questions about their health insurance coverage at the time of the survey. However, because of the timing of data collection, responses refer exclusively to this period. The current CPS ASEC coverage questions are essentially preparation for a deeper dive into questions about coverage during the previous calendar year. In official Census Bureau reports and tables, measures of health insurance indicate whether a person had a specific type of coverage at any time during the previous calendar year. The CPS ASEC uninsured rate represents the percentage of people who didn’t have any health insurance coverage in the previous calendar year. Publicly available data files include variables that indicate whether individuals had private, public, multiple forms of, or no coverage for all or part of the year.  

The greater detail in the CPS ASEC is related, in part, to differences in the surveys’ logistics. For example, Census Bureau field representatives or call center staff visit or call respondents to interview them for the CPS ASEC. 

The ACS was originally a self-administered survey conducted using paper forms, with nonresponse phone or in-person follow-up. Given the paper survey’s space limitations, the ACS was designed with fewer and less-detailed health insurance questions than the CPS ASEC. The ACS introduced an internet self-response mode in 2013, but the number of health insurance questions did not increase. More than half of ACS responses are now collected online.

Even with these and other differences in survey design and implementation, the surveys produce similar statistics on health insurance coverage. The main difference is the coverage period to which they refer – ACS to current and CPS ASEC to both current and previous-year coverage.

Because of its larger sample size, the ACS can be used to estimate current coverage for subnational geographies, such as states, counties, metropolitan areas, and congressional districts. This level of geographic detail is not available in the CPS ASEC or any other Census Bureau survey that collects data on health insurance.

Although the CPS ASEC does not support subnational estimates, the level of detail about insurance coverage is considerably richer than what is available in the ACS. For example, while the ACS data indicate whether someone paid a premium for coverage, the CPS ASEC goes a step farther, requesting the actual dollar amount paid in premiums.

For those with private coverage, the CPS ASEC asks whether respondents are the policyholders or received their coverage through another household member or someone living outside the household. The publicly available data files contain details on the availability of employer-sponsored coverage and reasons some eligible respondents did not take advantage of them.

Detailed CPS income data also make it possible to assess how changes in annual health insurance coverage rates may relate to changes in the nation’s overall economic well-being.

In summary, the ACS provides subnational estimates and the CPS ASEC more detailed health insurance coverage information.

For additional comparisons between the CPS ASEC and ACS, check out Guidance for Health Insurance Data Users.