Approximately five years ago, the Royal College emergency medicine programs in Canada implemented a competency-based paradigm and introduced the use of Entrustable Professional Activities (EPAs) for assessment of units of professional activity to assess trainees. Many competency-based medical education (CBME) based curricula, involve assessing for entrustment through observations of EPAs. While EPAs are frequently assessed in clinical settings, simulation is also used. This study aimed to characterize the use of simulation for EPA assessment. A study interview guide was jointly developed by all study authors and followed best practices for survey development. A national interview was conducted with program directors or assistant program directors across all the Royal College emergency medicine programs across Canada. Interviews were conducted over Microsoft Teams, interviews were recorded and transcribed, using Microsoft Teams transcribing service. Sample transcripts were analyzed for theme development. Themes were then reviewed by co-authors to ensure they were representative of the participants' views. A 64.7% response rate was achieved. Simulation has been widely adopted by EM training programs. All interviewees demonstrated support for the use of simulation for EPA assessment for many reasons, however, PDs acknowledged limitations and thematic analysis revealed certain themes and tensions for using simulation for EPA assessment. Thematic analysis revealed six major themes: widespread support for the use of simulation for EPA assessment, concerns regarding the potential for EPA assessment to become a "tick- box" exercise, logistical barriers limiting the use of simulation for EPA assessment, varied perceptions about the authenticity of using simulation for EPA assessment, the potential for simulation for EPA assessment to compromise learner psychological safety, and suggestions for the optimization of use of simulation for EPA assessment. Our findings offer insight for other programs and specialties on how simulation for EPA assessment can best be utilized. Programs should use these findings when considering using simulation for EPA assessment.