Availability and Receipt of Substance Use Disorder Treatment after Medicaid Expansion

Background and Objectives: The Affordable Care Act has shown great promise to increase the availability of substance use disorder (SUD) treatment by increasing eligibility for Medicaid through the program’s expansion. Since the start of expansion in 2014, an estimated 20-25 million previously uninsured Americans gained access to heatlh insurance. Of that number, an estimated 3.8 million have a substance use disorder requiring treatment. In this study, we assess the effects of Medicaid expansion on the availability and receipt of SUD treatment.

Methods: Study data were taken from two waves of the National Drug Abuse Treatment System Survey, collected through ninety-minute, internet-based survey of directors and clinical supervisors at 695 programs in 2014 and 657 programs in 2017. The response rate was 85% in each wave. We use a difference-in-difference models to assess change over time across four outcomes: program acceptance of Medicaid enrollees; the proportion of total clients insured by Medicaid; the proportion of clients who are uninsured; and the total number of past-year treatment admissions. We explore differences from 2013 to 2017 among programs in expansion and non-expansion states, accounting for variation in SUD treatment benefits across state Medicaid programs. Survey weights were used to adjust for selection into the sample.

Results: In states that expanded Medicaid, the proportion of treatment programs accepting Medicaid as a form of payment increased by ten percentage points (60% to 70%, p < 0.01). Programs in expansion states also reported a substantial increase in the proportion of clients with Medicaid (30% to 37%, p < 0.01), and a decrease in proportion of clients who were uninsured (35% to 22%, p < 0.01). No differences were observed across any of these domains in states that that did not expand Medicaid. Moreover, Medicaid expansion did not result in an increase in total past-year admissions to treatment; no differences were observed among programs in states that did and did not expand Medicaid.

Conclusions and Implications: Significant changes in substance use disorder treatment financing occurred between 2013 and 2017.  There was a substantial drop in the proportion of uninsured clients. Given a substantial increase in clients entering treatment insured by Medicaid, it is likely that the program’s expansion has been a major driver in driving down the number of uninsured. However, we found no evidence, as of yet, that these changes in financing resulted in an overall increase in treatment admissions in expansion states. It is possible that it may be too early to observe changes in admissions, given that capacity expansions take time to mount and implement. It is also possible that treatment programs are wary to the assume the financial risk involved in such an expansion, given the numerous legal challenges to the Affordable Care Act and ongoing political uncertainty regarding the future of the law.