Background: Interfacility transfer between hospitals is an integral component of regional healthcare systems. The decisions referring providers make regarding emergency medical services (EMS) level of care and transport modality (ground versus air) can dramatically impact patient care, emergency departments' workflow, hospital length of stay, and EMS resource availability. Limited research has been done to assess understanding of interfacility transport by emergency medicine providers. 
 Methods: We developed six patient scenarios to test knowledge of level of care and mode of interfacility transfer. Seven board-certified EMS physicians determined the optimal answer to each patient scenario. We distributed a survey with the scenarios to regional healthcare partners via a database of persons who utilize or interface with interfacility transport services. We collected answers to the patient scenarios and provider characteristics (primary practice site, sex, age, specialty, years since graducation, provider degree, EMS training received). Descriptive statistics were performed and Fisher's exact tests described differences in correct answers as they varied by specialty (emergency medicine or other specialty), provider type (physician or advanced practice provider), and reported training in EMS level of care. 
 Results: Seventy-six emergency medicine providers responded, including 68 physicians and 8 advanced practice providers. The mean total score on the case scenarios was 66%, with scores ranging from 33% to 100%. The mean scores on questions testing level of care and transport modality were 67% and 70%, respectively. No significant difference was found in test scores between emergency medicine and other specialties (p=0.718) or provider level of training (p=0.799). Training in EMS level of care was correlated with higher scores on the transport modality questions (p=0.003) but not on the level of care questions (p=0.231).
 Conclusion: Variability exists in the knowledge of providers on interfacility transport throughout the state. Emergency medicine providers could benefit from education on interfacility transfer resources.