Volume 54 | Number S1 | February 2019

Abstract List

Tyler N. A. Winkelman MD, MSc, Joel E. Segel, Matthew M. Davis


To examine the person‐level impact of Medicaid enrollment on costs, utilization, access, and health across previously uninsured racial/ethnic groups.

Data Source

Medical Expenditure Panel Survey, 2008‐2014.

Study Design

We pooled multiple 2‐year waves of data to examine the direct impact of Medicaid enrollment among uninsured Americans. We compared changes in outcomes among nonpregnant, uninsured individuals who gained Medicaid (N = 963) to those who remained uninsured (N = 9784) using a difference‐in‐differences analysis.

Principal Findings

Medicaid enrollment was associated with significant increases in total health care costs and total prescription drug costs and a significant decrease in out‐of‐pocket costs. Among those who gained Medicaid, prescription drug use increased significantly relative to those who remained uninsured. Medicaid enrollment was also associated with a significant increase in reporting a usual source of care, a decrease in foregone care, and significant improvements in severe psychological distress. Changes in total prescription drug costs and total prescription drug fills differed significantly across each racial/ethnic group.


Among a national sample of uninsured individuals, Medicaid enrollment was associated with substantial favorable changes in out‐of‐pocket costs, prescription drug use, and access to care. Our findings suggest Medicaid is an important tool to reduce insurance‐related disparities among Americans.