Abstract Minimally invasive techniques that are constantly evolving have increased the skill requirements for successful and safe surgical procedures. There has been an extensive effort in the last two decades to develop medical simulators for training surgeons. However, much of the work has focused on medical students and surgical residents who are currently in formal training programs. There is a recognized need to ensure practicing surgeons maintain their level of skills through continuous evaluation while simultaneously learning newer procedures or equipment that get adopted into the OR. The objective of this proposal is to develop, evaluate and validate simulation technologies to train, retrain and advance the performance and resiliency of practicing surgeons. We plan to develop open source software templates for rapid creation of high-fidelity simulations that include rare and adverse surgical events to enable practicing surgeons maintain and enhance their surgical skill. In this project, we propose extending Interactive Medical Simulation Toolkit (iMSTK)-an open source medical simulation platform, that has been used to prototype virtual trainers for laparoscopic surgery, orthognathic surgery and other clinical applications. We will develop software templates for rare and adverse event simulation, including hemorrhage (due to vessel puncture and unintentional cutting), thermal injury, anatomical variation, and physiological modeling. In most cases, physiological models are developed separately without coordination with interactive surgical simulation limiting their capability. In this project, we will integrate Kitware?s open source Pulse Physiological Engine with iMSTK to build a closed-loop physiology model that handles local physiological changes and global, systemic physiological responses. This project is a collaboration between Kitware Inc. and the University at Buffalo School of Medicine and Biomedical Sciences (UB) with an End-User Advisory Group (EAG) from Children National Medical Center (CNMC) and Baylor University Medical Center (BUMC). The institutes have a long record of collaboration in simulation technology development projects. We will demonstrate the new software templates by building a virtual surgical simulator for cholecystectomy with bile-duct injury and other complications that can occur in this type of surgery. The End-User Advisory Group will meet with the technical team on regular basis to provide feedback on the technical development. We will conduct face, content, and construct validity test and learning assessment to validate the simulator.