Association for Public Policy Analysis & Management

Medicaid expansion has increased access to opioid use disorder (OUD) medication treatment for low income Americans. To the extent that OUD treatment providers treat both Medicaid and Medicare patients and have capacity to treat additional patients, we expect positive spillovers to Medicare Part D beneficiaries. Using data from Medicare Part D (2010-2017), we found that Medicaid expansion increased the probability of a county having a buprenorphine (p<0.05) or injectable naltrexone OUD treatment provider (p<.01). Following expansion, the number of buprenorphine providers in expansion states increased by 6.3% (p<.05) and the number of injectable naltrexone providers increased by 3.2% (p<.01). Medicaid expansion states are better equipped to address the opioid crisis, not only in terms of the direct benefits to Medicaid beneficiaries but also in terms of the accessibility of OUD medications for Part D beneficiaries. However, additional efforts are likely needed to close the OUD treatment gap for Medicare beneficiaries.