Purpose
Mass casualty incident (MCI) simulations are typically used for disaster preparedness training, but their complexity also offers a unique opportunity to assess clinical reasoning, communication, and interprofessional collaboration in undergraduate medical education (UME). This presentation describes the use of an MCI format as a novel evaluation tool for UME learners, emphasizing both formative and summative assessment strategies.

Methods
An interprofessional MCI simulation was designed for second-year medical students and included real-time triage, role-based patient care, handoffs, and transitions across care settings (field, transport, and hospital). Learners interacted with peers from nursing, pharmacy, and EMS programs. Assessment tools included a combination of direct observation checklists, structured debriefing rubrics, and peer/team evaluations focused on leadership, adaptability, and communication. Faculty assessors were trained in advance to ensure calibration and inter-rater reliability. Data were analyzed to evaluate individual performance and identify curricular gaps.

Results
More than 100 students have participated since 2023. Evaluations revealed clear differences in teamwork, clinical prioritization, and adaptability under pressure. Students reported increased confidence and appreciation for interdisciplinary care. Faculty valued the opportunity to observe learners in action outside traditional assessments. The MCI format also allowed for equitable assessment across a large cohort within a single simulation event.

Conclusion
Using an MCI framework to evaluate UME learners adds authentic complexity to clinical assessment and offers scalable opportunities for interprofessional, competency-based evaluation. This model supports global efforts to modernize health professions education by aligning assessment with real-world demands and fostering cross-disciplinary collaboration.