State Prior Authorization Prohibitions and Buprenorphine Retention Among Privately Insured Patients.

Importance: Buprenorphine is the most commonly prescribed medication for opioid use disorder, but rates of retention in treatment remain low. Prior authorization (PA) has been identified as a barrier to the administration of buprenorphine, and patients may need multiple PAs to continue treatment; thus, many states have passed laws to prohibit the use of PA for buprenorphine in private insurance. Objective: To examine the association between PA prohibitions and buprenorphine treatment retention overall and by branded vs generic drug status. Design, Setting, and Participants: This cross-sectional study used a difference-in-differences design and private insurance claims data from 49 states and the District of Columbia with no PA prohibition for buprenorphine as of January 1, 2015. Patients aged 18 to 64 years who started a new buprenorphine treatment between January 1, 2015, and June 1, 2022, were included in the study. Data were analyzed from June 3, 2024, to December 31, 2025. Exposure: Prior authorization prohibitions, defined as state laws barring private insurers from using PA for any buprenorphine product. Main Outcomes and Measures: The main outcome was buprenorphine treatment retention, measured by a dichotomous variable indicating whether the buprenorphine treatment episode lasted 180 days or longer. Results: The sample included 22 946 patients (67.7% male) who started buprenorphine treatment; 54.3% started buprenorphine treatment with generic buprenorphine. A total of 30.4% of patients reached the 180-day treatment retention threshold. Adopting PA prohibitions was not associated with significant changes in buprenorphine treatment retention (effect estimate, 0.007; 95% CI, -0.044 to 0.059; P = .78). Stratified analysis by branded vs generic status of buprenorphine at the start of the treatment episode showed no significant association between PA prohibitions and treatment retention among patients receiving either branded (effect estimate, -0.018; 95% CI, -0.075 to 0.040; P = .55) or generic (effect estimate, 0.041; 95% CI, -0.036 to 0.118; P = .30) buprenorphine. Conclusions and Relevance: This cross-sectional study found that state laws prohibiting PA for buprenorphine were not associated with significant changes in buprenorphine treatment retention among privately insured patients. Prior authorization prohibition alone may not be effective in improving buprenorphine treatment retention. Additional interventions appear to be needed to address gaps in opioid use disorder treatment for privately insured patients.