The U.S. physician population lacks diversity, and this lack of diversity is reflected in the medical student population. Medical schools have implemented various types of programs to increase the diversity of their student population, and by extension, the physician population. A public Northeastern medical school implemented a postbaccalaureate premedical (PBPM) program for military enlisted service members with a goal to increase diversity among its medical school cohorts. A quantitative causal-comparative ex post facto study compared diversity variables of the PBPM military enlisted students with the public medical school student group, as well as the national student group.Chi-square analysis found significant differences between the military enlisted students and the two other comparison groups in four of five diversity measures. The military students were statistically different in age, marital status, number of dependents, and socioeconomic background. The groups did not differ significantly in terms of their racial/ethnic demographics. The study validated Tinto's framework of student persistence with a military population. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]