PURPOSE: A new internal medicine call structure was implemented at two teaching hospitals at the University of Toronto, Canada, in 2009, motivated by patient safety concerns, new duty hours regulations, and dissatisfaction among attending physicians. This study aimed to determine attendings', residents', and students' experiences with the new structure and to look carefully for unintended consequences. METHOD: Between June and August 2009, the authors conducted an in-depth qualitative study using level-specific focus groups of attending physicians, residents, and medical students (n=28) with experience of both the old and new call systems. Discussions were analyzed using grounded theory. RESULTS: Analysis revealed six themes (physician, manager, learner, teacher, workload, and "teamness") as well as the overarching theme of accountability. Although participants perceived the new system as better for patient care, there were several trade-offs. For example, workload was more predictable and equitable but less flexible, and senior residents reported less personal continuity for patients but increased continuity of care on the team level. Teaching and learning were negatively affected. Despite the negative effects, participants perceived that overall accountability improved on many levels, and participants felt the trade-offs were worth the perceived benefits. CONCLUSIONS: Residents were flexible and altruistic, accepting trade-offs in their own experiences in favor of patient care. Education was negatively affected. This study highlights the importance of carefully studying changes to look for anticipated and unanticipated consequences.