The US opioid overdose death epidemic has continued for over 20 years. Nonmetropolitan or rural areas with low capabilities of opioid use disorder (OUD) treatment are associated with significantly elevated rates of opioid overdose deaths. Many countries have increased OUD treatment access to reduce opioid morbidity by allowing community pharmacy dispensing of methadone for methadone maintenance treatment (MMT). MMT has been the most studied and longest utilized OUD treatment for about 55+ years. Federal regulations require MMT to be provided through one of about 1,860 SAMHSA certified opioid treatment programs (OTPs). MMT is considered less expensive (more affordable) and has higher treatment retention rates than buprenorphine treatment for OUD. Thus, MMT is a preferred treatment option for many individuals with OUD. However, the limited number of OPTs, limited capabilities of existing OTPs, and a long travel distance to an OTP are major barriers to accessing MMT, especially for persons with OUD in rural and suburban areas. Pharmacists are among the most trusted healthcare professionals. About 90% of Americans live within 5 miles of a community pharmacy. Federal regulations allow OTPs to obtain approvals to establish methadone medication units (MUs) at pharmacies (pharmacy MUs) to allow pharmacy administration and dispensing of methadone for MMT to expand treatment. MUs are managed by OTP directors of the parent OTP who have oversight of patient care at both the main OTP and MU location. MUs have been infrequently utilized in the US. Given the serious shortage of OUD providers in the US to address the escalating opioid overdose death epidemic, there is an urgent need to identify useful strategies of establishing MUs and to disseminate useful strategies of establishing MUs nationally to OTP directors and community pharmacists in the US. Built on the successful experience of the PI’s (Dr. Wu) research on developing physician-community pharmacist collaborative care models to engage community pharmacists in providing buprenorphine treatment care to patients with OUD (Wu et al., 2021a) and administration and dispensing of methadone for MMT (Wu et al., 2021b), we will conduct a survey of OTP directors (n=586) and community pharmacists (n=586) to identify OTP and community pharmacy facility/practice, individual, and contextual factors that are related to intentions to establish a MU. Guided by a mixed methods explanatory sequential design, we will also conduct follow-up qualitative interviews of a subsample of participants from each survey to further obtain in-depth data on MU implementation barriers and facilitators in the US. Due to the serious shortage of OUD providers and escalating rates of opioid deaths, this study is time-sensitive. This study will be the first effort in the US to identify MU implementation barriers and facilitators from both OTP directors and pharmacists. We will produce multiple peer-reviewed publications and an electronic tool...