For the last 25 years the scientific community, including academia, the National Institutes of Health (NIH), Food and Drug Administration (FDA), and the pharmaceutical industry have worked to improve the knowledge of medications used in children. Congress has passed legislations to provide incentives for drug development plans in pediatrics. The responsibility for the implementation and oversight for improving drug development has been delegated primarily to the FDA (for on-patent drugs) and to the NIH (for off-patent drugs). Even though the legislations have significantly improved the number of clinical studies conducted in children, gaps remain in areas such as developmental pharmacology, the ontogeny of drug metabolism, and the validation of outcome measures and endpoints in pediatric research. The first iteration of the Best Pharmaceuticals for Children Act (BPCA) Pharmacology Studies Task Order awarded in 2018 to the Pediatric Trials Network (PTN) started the paradigm of bridging the gap between pharmacokinetic (PK) related data (i.e., PK, pharmacodynamic, pharmacogenomic, efficiency, and safety data) with clinically relevant outcomes such as endpoints, biomarkers, and epidemiology data. This bridging is vital to the success of effectively treating pediatric patients in a personalized way. Pediatric populations and particularly the youngest (pre-term infants, newborns, and ages 2-5 years old) are at the highest risk for off-label drug use associated with the patient’s age, dosing or indication. Prolonged hospitalization and polypharmacy are also risks. Many drugs have multiple indications across medical specialties. There is a variation in the definition of off-label drug use in the literature. However, the prescribing of medication with limited evidence-based data on the dosing, short or long-term safety, and effectiveness is a common definition of what it means to use drugs ‘off-label’. Off-label use can increase the risks of adverse reactions, failed treatment responses, and unanticipated events. This new initiative of “Improving Off-label Medication Use in Children” will build upon the scientific knowledge gained in the PTN previous studies (Task Order 2) conducted from 2018-2022 that included the following: • Opportunistic Population Pharmacokinetic Study in Children (POPS). • Digoxin study in children with congenital heart disease The goal of the new task order will be to identify the remaining gaps in off-label use in children and to design clinical research (systematic literature reviews, epidemiology studies, population PK modeling studies, and innovative safety and effectiveness studies) on the identified off-label drugs that have been prioritized as a part of the BPCA prioritization process. The integration of the acquired knowledge from the different studies in this task order will provide a comprehensive data analysis that will lead to improving treatment approaches in neonatal (including maternal/fetal), pediatric, and adolesce...