Importance: Expanding treatment for opioid addiction has been recognized as an essential component of a comprehensive national response to the opioid epidemic. The Drug Addiction Treatment Act and its amendments attempted to improve access to treatment by involving office-based physicians in the provision of buprenorphine treatment.

Objectives: To estimate the association of availability of buprenorphine-waivered physicians with buprenorphine treatment use and, secondarily, with prescription opioid use among Medicaid enrollees.

Design, Setting, and Participants: This economic evaluation study used state-level panel data analysis to estimate the association between the number of buprenorphine-waivered physicians and the Medicaid-covered buprenorphine prescribing rate and opioid prescribing rate among Medicaid fee-for-service and managed care enrollees throughout the United States between January 1, 2011, and December 31, 2016.

Main Outcomes and Measures: Buprenorphine prescribing rate and opioid prescribing rate, measured as the number of buprenorphine prescriptions and opioid prescriptions covered by Medicaid on a quarterly basis per 1000 enrollees.

Results: The sample included 1059 quarterly observations. Two additional 100-patient-waivered physicians per 1 000 000 residents (approximately a 10% increase) were associated with an increase in the quarterly number of Medicaid-covered buprenorphine prescriptions of 0.46 (95% CI, 0.24-0.67) per 1000 enrollees and a reduction in the quarterly number of opioid prescriptions of 1.01 (95% CI, -1.87 to -0.15) per 1000 enrollees. Furthermore, 5 additional 30-patient-waivered physicians per 1 000 000 residents (approximately a 10% increase) were associated with an increase in the quarterly number of Medicaid-covered buprenorphine prescriptions of 0.37 (95% CI, 0.22-0.52) per 1000 enrollees and a reduction in the quarterly number of opioid prescriptions of 0.96 (95% CI, -1.85 to -0.07) per 1000 enrollees. A 10% increase in the number of buprenorphine-waivered physicians was associated with an approximately 10% increase in the Medicaid-covered buprenorphine prescribing rate and a 1.2% reduction in the opioid prescribing rate.

Conclusions and Relevance: Expanding capacity for buprenorphine treatment holds the potential to improve access to opioid addiction treatment, which may further reduce prescription opioid use and slow the ongoing opioid epidemic in the United States.