PROJECT SUMMARY/ABSTRACT Background: Gender minority youth (GMY; children, adolescents, and young adults whose gender identity differs from their birth-assigned sex) face a disproportionately high risk for serious mental health problems relative to cisgender youth (whose gender identity is congruent with their birth-assigned sex). These mental health inequities are exacerbated by treatment utilization barriers, including the dearth of mental health providers trained in gender-affirming care (i.e., practices that address the distinct experiences and mental health needs of gender minorities). The NIH and numerous scholars have called for increased efforts to develop and deploy interventions that improve access to, engagement in, and quality of, mental health interventions for gender minorities. Research: The proposed research will develop and pilot test a training intervention to increase mental health providers? use of gender-affirming practices. Intervention design (Aim 1) will utilize community-engaged and user-centered design methods, with systematic engagement from key stakeholders: GMY, their caregivers, as well as providers with and without expertise in gender-affirming care. Using an empirically-supported framework for behavioral intervention development, the intervention will be designed to affect three mechanisms hypothesized to result in behavioral change in providers (i.e., increased use of gender-affirming practices): knowledge, attitudes, and self-efficacy. Scalability of the intervention will be emphasized through the integration of mHealth technology. Intervention refinement (Aim 2) will involve two phases of user-centered design usability testing: (1) lab-based testing with focus groups of providers and (2) a case series study with 3 providers treating GMY consumers for 3 months. Feedback from usability testing will be used to iteratively refine the intervention and ensure the intervention?s readiness for pilot testing. The pilot test (Aim 3) will be an open trial in a multi-clinic mental health agency, aimed at examining the feasibility and acceptability of conducting a future RCT. Effectiveness and implementation data from both providers (N = 44) and consumers (i.e., GMY and their caregivers; N = 50 GMY) will be collected and analyzed. Candidate?s Career Development, Goals, and Environment: The proposed Mentored Patient-Oriented Research Career Development Award (K23) will provide Dr. Price with the advanced training and skills necessary to launch an independent research program focused on reducing mental health inequities for stigmatized youth and families through developing and evaluating training interventions, with an emphasis on GMY. Formal training and mentorship in (T1) mechanism-driven intervention development and testing, (T2) user-centered design, (T3) community-engaged research, and (T4) implementation science will support the successful execution of the primary research aims and Dr. Price?s career development. The immense resources available at Boston College, coupled with the vast expertise of Dr. Price?s mentorship and advisory team members, will further ensure the success of the research and training aims, and pave the way for a future RCT of the training intervention.