Volume 56 | Number 1 | February 2021

Abstract List

Steven C. Hill Ph.D., Salam Abdus PhD


To quantify the impact of Medicaid enrollment on access to care and adherence to recommended preventive services.

Data Source

2005‐2015 Medical Expenditure Panel Survey Household Component.

Study Design

We examined several access measures and utilization of several preventive services within the past year and within the time frame recommended by the United States Preventive Services Task Force, if more than a year. We estimated local average treatment effects of Medicaid enrollment using a new, two‐stage regression model developed by Nguimkeu, Denteh, and Tchernis. This model accounts for both endogenous and underreported Medicaid enrollment by using a partial observability bivariate probit regression as the first stage. We identify the model with an exogenous measure of Medicaid eligibility, the simulated Medicaid eligibility rate by state, year, and parents vs childless adults. A wide range of changes in Medicaid eligibility occurred during the time period studied.

Data Collection/Extraction methods

Sample of low‐income, nonelderly adults not receiving disability benefits.

Principal Findings

Medicaid enrollment decreased the probability of having unmet needs for medical care by 7.5 percentage points and the probability of experiencing delays getting prescription drugs by 7.7 percentage points. Medicaid enrollment increased the probability of having a usual source of care by 16.5 percentage points, the probability of having a routine checkup by 17.1 percentage points, and the probability of having a flu shot in past year by 12.6 percentage points.


Medicaid enrollment increased access to care and use of some preventive services. Additional research is needed on impacts for subgroups, such as parents, childless adults, and the smaller and generally older populations for whom screening tests are recommended.