Teams are the building blocks of the healthcare system, with growing evidence linking the quality of healthcare to team effectiveness, and team effectiveness to team training. Simulation has been identified as an effective modality for team training and assessment. Despite this, there are gaps in methodology, measurement, and implementation that prevent maximizing the impact of simulation modalities on team performance. As part of the 2017 Academic Emergency Medicine Consensus Conference "Catalyzing System Change Through Health Care Simulation: Systems, Competency, and Outcomes," we explored the impact of simulation on various aspects of team effectiveness. The consensus process included an extensive literature review, group discussions, and the conference "workshop" involving emergency medicine physicians, medical educators, and team science experts. The objectives of this work were to: 1) explore the antecedents and processes that support team effectiveness, 2) summarize the current role of simulation in developing and understanding team effectiveness, and 3) identify research targets to further improve team-based training and assessment, with the ultimate goal of improving healthcare systems.