In 1994 the Commonwealth of Pennsylvania announced a statewide Generalist Physician Initiative (GPI) modeled after The Robert Wood Johnson Foundation's GPI. Three-year grants totaling more than $9 million were awarded to seven of Pennsylvania's medical schools, including two that had already received GPI grants from the foundation. Stimulated by these initiatives, the state's six allopathic and two osteopathic medical schools decided to work together to develop a collaborative longitudinal tracking system to follow the careers of all their students from matriculation into their professional careers. This statewide data system, which includes information for more than 18,000 students and graduates beginning with the entering class of 1982, can be used to evaluate the impact of the Pennsylvania GPI, and it also yielded a local longitudinal tracking system for each medical school. This paper outlines the concept of the system, its technical implementation, and the corresponding implications for other medical schools considering the development of similar outcomes assessment systems.