Across health care, teamwork is a critical element for effective patient care. Yet, numerous well-intentioned training programs may fail to achieve the desired outcomes in team performance. Hope for the improvement of teamwork in health care is provided by the success of the aviation and military communities in utilizing simulation-based training (SBT) for training and evaluating teams. This consensus paper 1) proposes a scientifically based methodology for SBT design and evaluation, 2) reviews existing team performance metrics in health care along with recommendations, and 3) focuses on leadership as a target for SBT because it has a high likelihood to improve many team processes and ultimately performance. It is hoped that this discussion will assist those in emergency medicine (EM) and the larger health care field in the design and delivery of SBT for training and evaluating teamwork.