Opioid use disorder (OUD) is a common and often fatal chronic condition that can be effectively treated with medications (MOUD). Agonists (methadone, buprenorphine) are first-line treatments that reduce overdose risk. Black and Hispanic/Latinx patients are less likely to receive buprenorphine than non-Hispanic White patients. This raises equity concerns, as buprenorphine may be safer, easier to access and less stigmatizing than methadone for many patients. The novel coronavirus (COVID-19) pandemic resulted in increased flexibility in the provision of MOUD, including telemedicine initiations for buprenorphine. These policies may reduce existing disparities by lowering care barriers but could exacerbate disparities if they are not equally beneficial across groups. COVID-19-related policy changes present an unprecedented opportunity to examine impacts of a structural intervention—relaxed MOUD restrictions—on disparities generated by structural racism and discrimination (SRD). Guided by Public Health Critical Race praxis, which posits that racial/ethnic disparities in healthcare access are produced by SRD, this project will use mixed methods to evaluate how disparities in MOUD access may have changed in response to COVID-19-related policies in the Veterans Health Administration (VA), the nation's largest provider of substance use care, and how SRD contributes. Unequal access to buprenorphine is a significant problem nationally—studies estimate that Black patients with OUD are 50-60% less likely to access buprenorphine compared to White patients with similar disparities observed among Hispanic/Latinx patients. The proposed research can guide national and health-system-specific policy decisions regarding the continuation of relaxed MOUD prescribing guidelines post- COVID-19 and where to target resources to address SRD and its sequelae. Lessons learned from this historical event can influence future MOUD policy and practice, and it is essential that the impact on disparities and mechanisms underlying disparities be understood to optimize policy changes with regard to equity. This study aims to: 1) examine how changes in receipt of MOUD and retention following COVID-19 MOUD policies differ between Black and Hispanic/Latinx compared to non-Hispanic White patients with OUD; 2) examine how community-level sequelae of structural racism influence pre/post COVID-19 changes in MOUD receipt for Black and Hispanic/Latinx patients with OUD; and 3) qualitatively examine experiences of OUD care and perceptions of implementation of COVID-19-related policies among a sample of Black and Hispanic/Latinx patients with OUD. Aims 1-2 are observational cohort studies using national VA electronic health record (EHR) data for Black, Hispanic/Latinx, and non-Hispanic White patients with OUD. Aim 3 uses a qualitative study design involving semi-structured phone interviews with Black and Hispanic/Latinx VA patients with OUD. A stratified random sample will be balanced on gender ...