Surveys are the only source of data on the uninsured rate in the United States. The idea for a certain amount of federal monitoring of insurance status through standardized Internal Revenue Service (IRS) forms was included with the introduction of the Affordable Care Act (ACA), but the potential for estimating insurance status from IRS data is still in early stages of exploration. Thus, surveys remain the only source for insurance status data and, unfortunately, they are not without measurement error.

A new paper from SHADAC Investigator Kathleen T. Call, and former SHADAC researchers Joanne Pacscale and Angela Fertig explores two of the largest federal surveys from the United States Census Bureau - the American Community Survey (ACS) and the Current Population Survey (CPS) - to compare accuracy of coverage type and uninsured estimates produced by the health insurance modules after implementation of the Affordable Care Act. The sample was classified by coverage type - including two types of public coverage (Medicaid and a state-sponsored program) and three types of private coverage (employer-sponsored, non-group, and marketplace plans). Consistent with previous studies, this paper finds that accurate reporting of private coverage is higher than public coverage and in general, misreporting the wrong type of coverage is more likely than incorrectly reporting no coverage; the CPS module overestimated the uninsured by 1.9 and the ACS module by 3.5 percentage points. Other differences in accuracy metrics between the CPS and ACS are relatively small, suggesting that reporting accuracy does not necessarily need to factor in decisions about which source of survey data to use. Results also indicate that the Medicaid undercount has been substantially reduced with the redesigned CPS.