Diagnostic excellence is central to healthcare quality and safety. Prior literature identified a lack of psychological safety and time as barriers to diagnostic reasoning education. We performed a needs assessment to inform the development of diagnostic safety education. To evaluate existing educational programming and identify opportunities for content delivery, surveys were emailed to 155 interprofessional educational leaders and 627 clinicians at our hospital. Educational leaders and learners were invited to participate in focus groups to further explore beliefs, perceptions, and recommendations about diagnostic reasoning. The study team analyzed data using directed content analysis to identify themes. Of the 57 education leaders who responded to our survey, only 2 (5%) reported having formal training on diagnostic reasoning in their respective departments. The learner survey had a response rate of 47% (293/627). Learners expressed discomfort discussing diagnostic uncertainty and preferred case-based discussions and bedside learning as avenues for learning about the topic. Focus groups, including 7 educators and 16 learners, identified the following as necessary precursors to effective teaching about diagnostic safety: (1) faculty development, (2) institutional culture change, and (3) improved reporting of missed diagnoses. Participants preferred mandatory sessions integrated into existing educational programs. Our needs assessment identified a broad interest in education regarding medical diagnosis and potential barriers to implementation. Respondents highlighted the need to develop communication skills regarding diagnostic errors and uncertainty across professions and care areas. Study findings informed a pilot diagnostic reasoning curriculum for faculty and trainees.