State Funding For Substance Use Disorder Treatment Declined In The Wake Of Medicaid Expansion.

The US continues to grapple with an escalating epidemic of opioid-related overdose and mortality. State funds, which are the second-largest source of public funding for substance use disorder (SUD) treatment and prevention, play a critically important role in responding to this crisis. Despite their importance, little is known about how these funds are allocated and how they have changed over time, particularly within the context of Medicaid expansion. In this study we assessed trends in state funds during the period 2010-19, using difference-in-differences regression and event history models. Our findings reveal dramatic variation in state funding across states, from a low of $0.61 per capita in Arizona to a high of $51.11 per capita in Wyoming in 2019. Moreover, state funding declined during the period after Medicaid expansion by an average of $9.95 million in expansion states (relative to nonexpansion states), especially in states that expanded eligibility under Republican-controlled legislatures, where it declined by an average of $15.94 million. Medicaid substitution strategies, which, in effect, shift some of the financial burden for financing SUD treatment from the state to the federal level, may erode resources for broader system-level efforts that are urgently needed in the midst of the opioid epidemic.