The Maryland Current Population Survey Medicaid Undercount Study

Abstract

In an effort to better understand the source of the discrepancy, the Maryland Department of Health and Mental Hygiene (DHMH), the state agency responsible for the Medicaid program, retained the Center for Health Program Development and Management (Center) at the University of Maryland, Baltimore County to conduct a survey to evaluate the completeness of the CPS data on reported Medicaid-eligible individuals in Maryland. Through the administration of a survey modeled after the CPS questionnaire, the Center found that: • Three-quarters of respondent households (selected from Medicaid enrollment files) indicated that at least one member of the household had been enrolled in Medicaid, HealthChoice, or the Maryland Children’s Health Program. ii • An additional 12.5 percent indicated enrollment when we added a question not contained in the CPS instrument, which identified Medicaid by the name “Medical Assistance.” The findings from this study indicate that the discrepancy between the CPS estimate of Medicaid enrollment in the state and Maryland’s administrative data estimates results primarily from an undercount on the part of the CPS that could be significantly corrected if Medical Assistance was included in the CPS survey instrument as an alternate name for the Maryland Medicaid program. We estimate that the inclusion of the Medical Assistance option in the CPS questionnaire would have resulted in an estimated undercount of between 22 and 27 percent for 2003, a considerable improvement over the current 34 to 38 percent.