Clinical supervision requires that supervisors make decisions about how much independence to allow their trainees for patient care tasks. The simultaneous goals of ensuring quality patient care and affording trainees appropriate and progressively greater responsibility require that the supervising physician trusts the trainee. Trust allows the trainee to experience increasing levels of participation and responsibility in the workplace in a way that builds competence for future practice. The factors influencing a supervisor's trust in a trainee are related to the supervisor, trainee, the supervisor-trainee relationship, task, and context. This literature-based overview of these five factors informs design principles for clinical education that support the granting of entrustment. Entrustable professional activities offer promise as an example of a novel supervision and assessment strategy based on trust. Informed by the design principles offered here, entrustment can support supervisors' accountability for the outcomes of training by maintaining focus on future patient care outcomes.