Association for Public Policy Analysis & Management

Nationally, between 2006 and 2013 rates of emergency department visits by individuals age 15 and older involving mental and substance abuse disorders increased steadily. As the largest payer of behavioral health services in the U.S., Medicaid faced an urgent challenge as spending for those with a behavioral health diagnosis is nearly four times higher than for those without. This was a particularly salient issues for states expanding Medicaid in 2014, in accordance with the ACA. At inception, the federal government provided 100% of funding for expanded enrollment, but beginning in 2020 states would be required to fund 10% of the costs, in addition to the 25-50% they allocate for pre-ACA Medicaid populations. Using U.S. Healthcare Cost and Utilization Project (HCUP) data from 2013-2015 we employ a differences in differences methodology to compare key measures of behavioral health-related use of the emergency departments (percentage of total visits, weekend usage, and severity of visit) for states that did and did not expand Medicaid coverage. While we do not find significant reduction in the percentage of total visits following expansion of coverage, we do observe meaningful differences when examined by demographic characteristics. These findings support calls for integrating greater care coordination for those with serious behavioral health diagnoses into future coverage expansion proposals as a means to provide more comprehensive care and mitigate rising associated costs.