<imgsrc=”” border=”0″ align=”left” alt=”image”>When taken as prescribed, buprenorphine is effective in reducing opioid withdrawal, cravings, and use and preventing fatal overdose among people living with opioid use disorder (OUD). Despite the well-documented potential of buprenorphine provision to curb the opioid and overdose crises, this medication is severely underutilized in the treatment of OUD, particularly among low-income Medicaid beneficiaries who represent a sizable portion of the U.S. population living with OUD. This commentary focuses on a critical yet under-studied barrier to buprenorphine access – Medicaid prescription caps that limit the number of prescriptions an individual can fill in a given month. Here, we describe the persistence of monthly Medicaid prescription caps across the U.S.; discuss how these caps could present barriers to medication access and optimal health among diverse populations; describe the state of research on Medicaid prescription caps and buprenorphine use; and call for empirical research to document the impact of Medicaid prescription caps on OUD treatment and overdose outcomes to inform future policy changes aimed at improving access to buprenorphine as a means of combating the opioid and overdose crises.