Population surveys are the only source of estimates of the number of uninsured people in the United States and of those who are potentially eligible for public programs but who are not enrolled. The term “Medicaid undercount” refers to surveys that undercount the number of Medicaid enrollees. Those who study health insurance coverage report that Medicaid enrollees often misreport their health insurance status. The authors’ goal in this paper is to report how often and why enrollees misreport their status. The study surveyed known public program enrollees in Florida, Pennsylvania and California to learn how they responded to health insurance questions. The results showed that:
- Known nonelderly Medicaid recipients were fairly accurate reporters of their insurance status.
- Many enrollees also accurately reported the type of insurance coverage.
- Some respondents did not report Medicaid coverage at all.
- Full benefit enrollees were more likely to accurately report their insurance status than partial benefit enrollees.
These findings suggest that policy-makers should have confidence in using survey data to monitor health insurance coverage, eligibility for coverage and characteristics of the uninsured.