Project Summary There is increasing attention to racial-ethnic disparities and inequities in the United States. The opioid epidemic and the COVID-19 pandemic exposed pre-existing racial-ethnic disparities, stigma, and implicit biases in treatment settings. The causes of racial-ethnic disparities on populations of color with substance use disorder (SUD), in the context of clinical encounters, have been long understudied. In this proposed administrative supplement grant, we aim to leverage the existing data from the parent grant, “Coaching Performance Driven Practice Change in the Context of Value Based Purchasing Under New York Medicaid (CARE study) (R33DA049252-01)” and supplement it by addressing racial-ethnic disparities using an explanatory sequential mixed-methods approach, guided by the Kilbourne framework for studying disparities in healthcare. The aims of this research is to (1) detect clinic-level racial disparities in retention and (2 & 3) understand clinical encounter experiences of patients and providers across clinics that have high- or low-quality metrics. Specific Aim 1 will be achieved using Medicaid and other state administrative data, by examining variation at the clinic level disparities and clients’ use of the following quality metrics of patient encounters: use of MOUD, frequency of individual and group counseling, technology (i.e., telehealth), urine screening, patient reported treatment progress, and retention. Specific Aim 2 & 3 will be informed by findings from Aim 1. We plan to conduct interviews with patients (Aim 2) and providers (Aim 3) from a sample of clinics to understand diverse experiences in patient-provider encounters. Taken together, these aims can help explain why and how racial- ethnic disparities attribute to exacerbated outcomes for people of color by focusing on multiple levels of potential factors including their clinical encounters. Our proposed aims will inform the development of interventions that reduce or eliminate treatment disparities for patients with SUD.