Date of Award


Document Type

Campus Access Dissertation

Degree Name

Doctor of Philosophy (PhD)


Public Policy

First Advisor

Michael P. Johnson

Second Advisor

Frank W. Porell

Third Advisor

Dominic Hodgkin


Medicaid has assisted the poor by paying for health care since 1965. In 2014, the Affordable Care Act (ACA) replaced states’ varying existing income eligibility thresholds with a uniform standard, 138 % of the Federal Poverty Line, applied to all states that chose to expand access to Medicaid. Furthermore, low-income, nonelderly childless adults in these ‘expansion states’ were newly eligible for Medicaid while they were not eligible in most states regardless of income level.

Andersen’s Health Behavioral Model provides the theoretical framework to analyze the role of Medicaid expansion on individual access and health outcomes. This dissertation answers two questions: ‘What is the effect of the ACA Medicaid expansion on insurance status, access to care, and health outcomes for nonelderly low-income adults and a subset of these population without children?’ and second, ‘Does the ACA Medicaid expansion reduce disparities in these outcomes among racial/ethnic subgroups?’ I estimated difference in differences models on the National Health Interview Survey data (2010-2016) using multiple outcome measures. My estimates of the effects of the ACA Medicaid expansion on racial/ethnic disparities used the Institute of Medicine and the Residual Direct Effect definitions of health care disparities.

This dissertation adds new findings on racial/ethnic health care disparities to the existing ACA literature. I identify significant decreases in uninsured rates and increases in Medicaid coverage among all racial/ethnic subgroups. Moreover, I find evidence that the ACA Medicaid expansion has more favorable impacts on racial/ethnic minorities for unmet needs of care due to cost but not for visiting doctors and health status. The findings suggest that policymakers should consider financial and other aspects together since financial resources such as Medicaid directly help to access to care, there still remain other individual-and contextual-level contributors to access to care and health outcomes.


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