Background: Buprenorphine is a life-saving medication for people with opioid use disorder (OUD). U.S. federal law allows advanced practice clinicians (APCs), such as nurse practitioners (NPs) and physician assistants (PAs), to obtain a federal waiver to prescribe buprenorphine in office-based practices. However, states regulate APCs' scope of practice (SOP) variously, including requirements for physician supervision. States may also have laws entirely banning NP/PA buprenorphine prescribing or requiring that supervising physicians have a federal waiver to prescribe buprenorphine. We sought to identify prevalence of state laws other than SOP laws that either 1) prohibit NP/PA buprenorphine prescribing entirely, or 2) require supervision by a federally waivered physician. Methods: We searched for state statutes and regulations in all 50 states and Washington D.C. regulating prescribing of buprenorphine for OUD by APCs during summer 2021. We excluded general scope of practice laws, laws only applicable to Medicaid-funded clinicians, laws not applicable to substance use disorder (SUD) treatment, and laws only applicable to NPs/PAs serving licensed SUD treatment facilities. We then conducted content analysis. Results: One state prohibits all APCs from prescribing buprenorphine for OUD, even though the state's general SOP laws permit APC buprenorphine prescribing. Five states require PA supervision by a federally waivered physician. Three states require NP supervision by a federally waivered physician. Conclusions: Aside from general scope of practice laws, several states have created laws explicitly regulating buprenorphine prescribing by APCs outside of licensed state SUD facilities.