Few industries match the scale of health care. In the United States alone, an estimated 85% of the population has at least 1 health care encounter annually and at least one quarter of these people experience 4 to 9 encounters annually. A single visit requires collaboration among a multidisciplinary group of clinicians, administrative staff, patients, and their loved ones. Multiple visits often occur across different clinicians working in different organizations. Ineffective care coordination and the underlying suboptimal teamwork processes are a public health issue. Health care delivery systems exemplify complex organizations operating under high stakes in dynamic policy and regulatory environments. The coordination and delivery of safe, high-quality care demands reliable teamwork and collaboration within, as well as across, organizational, disciplinary, technical, and cultural boundaries. In this review, we synthesize the evidence examining teams and teamwork in health care delivery settings in order to characterize the current state of the science and to highlight gaps in which studies can further illuminate our evidence-based understanding of teamwork and collaboration. Specifically, we highlight evidence concerning (a) the relationship between teamwork and multilevel outcomes, (b) effective teamwork behaviors, (c) competencies (i.e., knowledge, skills, and attitudes) underlying effective teamwork in the health professions, (d) teamwork interventions, (e) team performance measurement strategies, and (f) the critical role context plays in shaping teamwork and collaboration in practice. We also distill potential avenues for future research and highlight opportunities to understand the translation, dissemination, and implementation of evidence-based teamwork principles into practice.