A case of a young adult patient in the days immediately after a cancer diagnosis illustrates the critical importance of three interrelated core coordinating mechanisms-closed-loop communication, shared mental models, and mutual trust-of teamwork in an adolescent and young adult multidisciplinary oncology team. The case illustrates both the opportunities to increase team member coordination and the problems that can occur when coordination breaks down. A model for teamwork is presented, which highlights the relationships among these coordinating mechanisms and demonstrates how balance among them works to optimize team function and patient care. Implications for clinical practice and research suggested by the case are presented.