BACKGROUND and INTRODUCTION The Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD) provides clinical trial sites to the International Maternal Pediatric Adolescent AIDS Clinical Trials Group (IMPAACT). The IMPAACT network and its leadership group are in charge of the creation of all their studies, protocols, and clinical trials. These activities are funded through Grants/Cooperative agreements sponsored by NIAID. The IMPAACT Network is a cooperative group of institutions, investigators, and other collaborators mainly focused on evaluating potential therapies for HIV infection and its related symptoms and co-infections in infants, children, adolescents and pregnant women. This includes clinical trials of HIV/AIDS interventions for the prevention of mother to child transmission. In 1990 the NICHD began collaborating with the PACTG to expand clinical trial availability at NICHD clinical trial centers/sites. This collaboration made possible to conduct clinical trials by the IMPAACT Network to further evaluate antiretroviral therapeutic agents, other therapies targeted at opportunistic infections, and interventions to prevent perinatal HIV transmission. In recent years, the collaboration is expanding to evaluate potential HIV cure approaches and vaccines. SCOPE AND OBJECTIVES This task order is to provide Core infrastructure support at the clinical sites comprising the NICHD multi-site network of domestic and international clinical centers conducting IMPAACT Network protocols. Core infrastructure includes routine tasks for maintaining site readiness to conduct clinical trials for evaluation of investigational therapies, diagnostic techniques, prevention strategies, epidemiology and natural history of multiple aspects of HIV infection in pediatric, adolescent, and maternal patient populations.