PROJECT SUMMARY/ABSTRACT In response to Notice of Special Interest (NOT-DA-21-044) highlighting the urgent need to conduct substance use research and to promote health equity, we seek to strengthen work on the parent grant, “Gender differences in access and engagement in medication-assisted treatment for opioid use disorder.” Building on our quantitative findings on gender and race/ethnic differences in access, retention and treatment completion in opioid treatment, we propose to use qualitative data to enhance identification of barriers, facilitators and strategies in the implementation of a standard of care (that includes components of medication, comprehensive health/social and culturally responsive care) to reduce disparities and improve health equity among women and race/ethnic minority groups in Los Angeles County. We will examine the implementation process using theories of (1) expertise and (2) phased implementation (EPIS framework-Exploration Preparation, Implementation and Sustainment) as well as qualitative methods. We will collect, analyze and interpret qualitative data from 30 providers in these communities and identify strategies to improve the implementation of the evidence-based standard of care for OUD treatment. We also will use these data to enrich and give meaning to the quantitative findings in the parent grant and ultimately contribute to reducing disparities and promotion of health equity in treatment for OUD in low resource communities.