The Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), with other NIH Institutes and Centers (ICs) including the National Institute on Drug Abuse (NIDA), the National Institute of Mental Health (NIMH), and the Fogarty International Center (FIC), intends to promote a new initiative by publishing a Notice of Funding Opportunity (NOFO) to solicit applications to participate in a research program cooperative agreement to support the Prevention and Treatment through a Comprehensive Care Continuum for HIV-affected Adolescents in Resource Constrained Settings Implementation Science Network (PATC3H-IN). The Network will expand and/or improve successes achieved by PATC3H to new geographic settings with limited implementation science (IS) research capacity and/or risk populations who are poorly represented in international adolescent HIV research (e.g. sexual and gender minorities; commercial sex workers; drug users) and stimulate much needed IS research in a neglected area of public health significance: prevention of new HIV infections among adolescents at risk and the identification of, and linkage and retention to care of and long-term viral suppression among youth living with HIV in low-to-middle income countries (LMICs). These settings must have an HIV epidemic density defined byUNAIDS estimatesas either a country 1) in which at least 200,000 people are living with HIV and the number has not decreased by more than 5% over the last 2 consecutive years of available data or 2) has an HIV incidence among youth ages 10 to 24 years of 0.01% or more. The structure of PATC3H-IN shall consist of three highly integrated components: (1) 4-5 UG1 Clinical Research Centers (CRC), applications for which have previously been solicited (RFA-HD-23-013); (2) a Coordination and Operations Center (COC); and (3) an Implementation Science Coordinating Center (ISCC). This Notice serves to announce a forthcoming NOFO that solicits applications for a single Implementation Science Coordinating Center. This Notice is being provided to allow potential applicants sufficient time to develop meaningful collaborations and responsive projects. To apply, investigators will be expected to demonstrate capacity to form successful collaborations, both within the PATC3H-IN network and among its investigators as well as with external stakeholders, to advance achievement of the research objectives and maximize sustainability of efficacious interventions and best practices. The NOFO is expected to be published in Summer 2023 with an expected application due date in Winter 2023. This NOFO will utilize the UM2 (Clinical Trial Optional) activity code. Details of the planned NOFO are provided below.