UCLA Rapid, Rigorous, Relevant Implementation Science Hub: Leveraging Implementation Science to End the HIV Epidemic - Modified Project Summary/Abstract Section With its focus on developing and deploying evidence-based strategies into routine practice to optimize healthcare value and population health, implementation science (IS) plays a cross-cutting role in ending the HIV epidemic. Moving substantial investments in HIV research into implementation in rapid, rigorous, and relevant (3R) ways is critical. Now entering its fifth year, the UCLA Rapid, Rigorous, Relevant Implementation Science Hub (UCLA 3R Hub) proposes to provide the NIH and the Coordination, Consultation, and Data Management Center (CCDMC) with IS expertise and, in collaboration with other Regional Consultation Hubs (RCHs), meet the demand for effective and efficient ways to translate HIV research into practice. The goal of the UCLA 3R Hub is to provide leadership, resources, and support for 3R HIV-related implementation research emphasizing pragmatic study designs and community-involved methods and strategies to improve HIV outcomes. Over the next five years, in response to calls to integrate IS with quality improvement (QI, a rapid and iterative approach to change), the UCLA 3R Hub will also build capacity at the intersection of IS and improvement science (the foundational science and methods of QI). Our Specific Aims are to: 1) Provide technical assistance (TA), coaching, and consultation to a defined set of research projects by: a) offering expert guidance and support to inform project planning, execution, evaluation, and dissemination; b) supporting the projects with data harmonization and reporting requirements; c) highlighting best practices that will support implementing agencies; and d) fostering opportunities for collaboration across research teams. 2) Collaborate and coordinate with the CCDMC by: a) collecting specified data from awarded projects; b) conducting a systematic review of promising strategies identified in previous projects and developing evidencebased policy/practice recommendations; and c) engaging in cross-network activities. 3) Enhance IS capacity in the institutional, local, regional, and national HIV research communities by: a) delivering Beachside Chats and high-quality workshops on pragmatic methods and strategies; b) fostering multidisciplinary, multi-institutional research teams; and c) building a centralized infrastructure at UCLA to advance high-impact implementation research focused on ending the HIV epidemic and related conditions. 4) Enable locally driven solutions to implementation challenges through integrating improvement science into our IS capacity-building efforts by: a) providing training and mentoring on improvement science methods, including evidence-based QI (EBQI); and b) working with practitioners and healthcare partners to identify opportunities for, and to demonstrate, application of these methods. The UCLA 3R Hub will be led by an outstanding cadre of implementation scientists, improvement scientists, and HIV researchers, all of whom have strong expertise in prioritizing health equity and engaging investigators and practitioners.