INTRODUCTION: A growing number of individuals with significant medical histories travel for business and holidays. Precise anticipation and stratification of transport-relevant illness severity in the planning stage of an air medical evacuation is crucial for mission success and patient safety. METHODS: We developed a staging system (ie, Stratification of Air Medical Transport by Expression of Symptoms in Patients [STEP]) and applied it to 356 patients transported by a fixed wing aircraft between January 2010 and June 2011. Patients were stratified before transport, and the transport team performed independent staging of each patient during the actual transport. Data on transport modes, transport time, age, sex, diagnosis, the need for mechanical ventilation, and transport-related complications were collected. Data were analyzed for significant differences in STEP categories between operations staging and staging by the flight crew and for the correlation between operations STEP staging and actual transport acuity. RESULTS: Complete datasets were available in 353 of 356 patients. Differences between staging by operations and flight crew were documented in 31 cases (P = .809); in 18 of them, the flight crew considered the patient to be more severely affected than previously estimated. Decisions for specific transport mode and configuration were found to be adequate in all but 3 cases (99.15 ). CONCLUSION: STEP is a useful tool to assess patient s illness/injury severity in the planning stage of a long distance, international, air ambulance transport and assists in choosing the appropriate mode and configuration of transport.