© Copyright 2017 International Pediatric Research Foundation, Inc. Research on neonatal AKI definition is evolving and must consider physiology (e.g., developmental GFR increase) while allowing for flexibility to include future validated markers of structural/tissue injury. Neonatal AKI definitions will enable rigorous clinical and translational research. A summary of research recommendations and knowledge gaps is provided in Table 2. Multicenter studies (such as The Neonatal Kidney Collaborative group, formed subsequent to this NIH workshop) to address these knowledge gaps and determine definitions that are most feasible and best predict outcomes are needed (4). Until a widely accepted definition is available, researchers should strive to use rational, physiology-based SCr and urine output definition criteria and clearly describe methods used to define neonatal AKI, in published data, in order to move this field forward.