Prior authorization (PA) requirements for buprenorphine are associated with lower provision of the medication for the treatment of opioid use disorder (OUD). While Medicare plans have eliminated PA requirements for buprenorphine, many Medicaid plans continue to require them. To describe and classify buprenorphine coverage requirements based on thematic analysis of state Medicaid PA forms. This qualitative study used a thematic analysis of 50 states' Medicaid PA forms for buprenorphine between November 2020 and March 2021. Forms were obtained from the jurisdiction's Medicaid websites and assessed for features suggesting barriers to buprenorphine access. A coding tool was developed based on a review of a sample of forms, including fields for behavioral health treatment recommendations or mandates, drug screening requirements, and dosage limitations. Outcomes included PA requirements for different buprenorphine formulations. Additionally, PA forms were evaluated for various criteria such as behavioral health, drug screenings, dose-related recommendations or mandates or patient education. Among the total of 50 US states in the analysis, most states' Medicaid plans required PA for at least 1 formulation of buprenorphine. However, the majority did not require a PA for buprenorphine-naloxone. Four key themes of coverage requirements were identified: restrictive surveillance (eg, requirements for urine drug screenings, random drug screenings, pill counts), behavioral health treatment recommendations or mandates (eg, mandatory counseling or 12-step meeting attendance), interfering with or restricting medical decision-making (eg, maximum daily dosages of 16 mg, requiring additional steps for dosages higher than 16 mg), and patient education (eg, information about adverse effects and interactions with other medications). Eleven states (22%) required urine drug screenings, 6 states (12%) required random urine drug screenings, and 4 states (8%) required pill counts. Fourteen states' forms (28%) recommended therapy, and 7 (14%) required therapy, counseling, or participation in group sessions. Eighteen states (36%) specified dosage maximums; among them, 11 (22%) required additional steps for a daily dosage higher than 16 mg. In this qualitative study of state Medicaid PA requirements for buprenorphine, themes were identified that included patient surveillance with drug screenings and pill counts, behavioral health treatment recommendations or mandates, patient education, and dosing guidance. These results suggest that state Medicaid plans' buprenorphine PA requirements for OUD are in conflict with existing evidence and may negatively affect states' efforts to address the opioid overdose crisis.