Patient handovers are a source of significant medical errors, especially in an operational environment where austere settings and numerous levels of patient handoffs demand more attention and increase risk. Our previous work highlighted the poor quality of patient handovers, with many errors in critical information, a lack of structure and closed loop communication. Our group interviewed subject matter experts in tactical handovers, reviewed the literature on effective handover communication and designed The Effective Combat Casualty Care Handoff Operations (ECCCHO) project to teach TCCC learners the concise and accurate handover of patient data in verbal and written form reflecting best practices in the field. The aim of this study was to measure the effect of a new curriculum (ECCCHO) on the handover performance of subjects compared to a cohort of subjects who received usual handover training. The project was approved by the Institutional Review Board of Uniformed Services University as an exempt study. Subjects for this study were students at the Uniformed Services University (USUHS) School of Medicine. End of first year medical students participate in field training called the Advanced Combat Medical Exercise (ACME). The ACME course covers topics in TCCC and students receive lectures on patient handovers. Students then go to the field and perform life savings skills on patient actors and mannequins. A random sample of subjects were observed by faculty and their performance recorded on checklists. Students attending ACME 2022 (n=32) represent our control group who received the usual training in patient handovers. Students participating in ACME 2024 (n=102) represent our intervention group. This group received ECCCHO training prior to their field exercise which consisted of a brief lecture on documenting data in the DD1380; using the mechanism of injury, injuries sustained, signs/symptoms, and treatments (M.I.S.T.) format to convey information; asking for a read back of the handover; making a definitive handover statement and then transferring the DD1380 card. Subjects then practiced these skills in a tabletop simulation exercise three times. Total training time was 45 minutes. A random sample of subjects were then observed in the ACME 2024 field exercise where observers documented patient handovers between a student posing as a medic (sender) to a faculty member (receiver) in a tactical environment. Observers in ACME 2024 used the same performance checklist that was used in the ACME 2022 group. Outcome variables in both groups were: (1) The percent of subjects who explicitly mentioned a mechanism of injury, the injuries sustained, any signs/symptoms and any treatments rendered, (M.I.S.T. format); (2) whether or not the senders explicitly requested read backs; (3) whether or not the pair explicitly made a definitive handover statement (e.g. “the patient is yours.../the patient is mine”) and (4) whether or not the DD1380 was transferred. Data from ACME 2024 was compared to data from ACME 2022 controls and analyzed via T-test and Chi Square analyses for differences. Results of our study showed significant differences in handover performance among subjects who received ECCCHO training compared to usual handover training especially in the area of closed loop communication and adherence to the M.I.S.T. format. Our conclusion is that ECCCHO training, a multifaceted brief intervention, was superior to TCCC handover training in USUHS medical students in a tactical environment. Future studies will measure the retention of ECCCHO principles over subsequent years.