Did the Medicaid Expansion Crowd Out Other Payment Sources for Medications for Opioid Use Disorder? Evidence from Rhode Island
Using information from the all-payer claims database for Rhode Island covering more than three-quarters of health insurance enrollees in the state from April 2011 through May 2019, this paper offers new measures of the association between the Medicaid expansion and the rate of receipt of buprenorphine and methadone for opioid use disorder (OUD). These robust measures adjust for the extent to which new Medicaid payments for these medications that started in 2014 crowded out payments from either non-Medicaid insurance or from non-insurance subsidies for the treatment of opioid abuse. The authors find that crowding out was nontrivial but incomplete for either buprenorphine or methadone, such that the Medicaid expansion in Rhode Island appears to have enabled many patients to access medications for OUD for the first time. These findings offer support for the expansion of Medicaid in states that have not already done so.