Over the past 20 years, the U.S military has significantly increased it use of medical simulations for training. In 1996, the Army began structured research and development (R&D) to bridge the training gap between the traditional warfighter and the medical warfighter.  From that effort, significant progress has been made that has shaped the medical simulation and training industry.  The last 20 plus years saw the development and refinement of full body manikins and task trainers specifically designed for the military.  It also saw the emergence of virtual environments and virtual patients.  Additionally, surgical simulations advanced as visually immersive and more natural hand held devices reached technology maturation. 

Many of the developments were pursued by the R&D community because they met a current critical training gap identified by the training community.  As the Department of Defense moves into the next decade a more strategic approach is desired and needed.  Resources are limited, and there is a desire to work across the Joint medical and Warfighter communities.  Challenges still exist, including interoperability across simulations platforms, scaling simulation and training fidelity to the needed complexity as well as for the different levels of medical care providers, tailoring training content to the learner, objective performance measures, and natural and meaningful interactions with simulated patients.

This paper will present a brief history of successes, lessons learned and future challenges. It will focus on several projects, as representative case studies, that have gone from a concept, through research and development, testing, and transition to fielded capabilities.  It will also include a path forward as the medical simulation and training community moves to a more unified approach across the services.