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2021 Honors Thesis: Julia van Helmond


Julia van Helmond

Title of Thesis:

The Effect of Medicaid Expansion on the Accessibility of Facilities Offering Mental Health Services


Ian McCarthySara Markowitz, Dana Haugaard (Visual Arts)


Medicaid is the principal payer of behavioral health services in the U.S. and has been shown to increase healthcare utilization while decreasing the likelihood of having an unmet need for these services. Still, significant barriers remain in the provision of mental health care, including inadequate reimbursements to both primary care providers and mental health specialists, low rates of insurance acceptance by specialists, and an uneven distribution of resources. The objective of this paper is to examine the effect of the Medicaid Expansion program on state-level accessibility to facilities offering mental health services. Locational data for these facilities is obtained from the facility directories published yearly by the Substance Abuse and Mental Health Services Administration. Regression models with state fixed effects are used to estimate the treatment effect using a difference-in-difference identification strategy. Various measures of accessibility are considered, including the number of facilities in a state weighted by population estimates and the proportion of a state’s population living in a zip code with at least one facility. An initial descriptive analysis of the data supported several findings from prior research, such as the generally uneven distribution of mental health resources across the U.S. and significant disparities in accessibility according to urban status. Average accessibility scores show slightly greater increases in expansion states, especially during the first two years following enactment of the program. In general, however, results are not suggestive of any large difference between the two groups of states with regards to changes in state-level accessibility. This paper also considers several potential heterogeneities in the effect of the expansion program on mental health care accessibility according to certain facility characteristics. The average accessibility of facilities offering services in an outpatient setting increases more in expansion states, which may be in part due to the increasing role of primary care physicians in the provision of mental health services. Results suggest several policy interventions, including more widespread adoption of integrative and collaborative care models, as well as targeted reimbursement policies that encourage Medicaid acceptance and allow for growth of the mental health care system across various service settings.

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