The effect of Medicaid expansion on use of opioid agonist treatment and the role of provider capacity constraints.

Gains in health coverage may not be sufficient to increase OUD treatment, even in the context of high treatment need. Provider capacity likely limited Medicaid expansion's effect on buprenorphine dispensed. Policies to increase buprenorphine providers, such as ending the waiver requirement, may be needed to ensure coverage gains translate to treatment access.