Extracurricular programs for science, technology, engineering and mathematics (STEM) content for middle and high school students are growing in number and are distributed utilizing in-class learning, after school clubs and activities and summer internship programs. It is often the case that anecdotal evidence of an internship program’s effectiveness is plentiful but quantitative data to support this evidence is lacking. In this paper we discuss how the existing organizational turnover literature may be leveraged to explore student interest and retention in STEM career paths. This approach was inspired by the summer modeling and simulation (M&S) program conducted by the Air Force Research Laboratory’s (AFRL) Gaming Research Integration for Learning Laboratory (GRILLTM). We describe the basic features of the GRILL™ program and classify dimensions in behavioral change that have emerged over four years of the program. By interpreting these data through the theoretical framework of retention and turnover, specifically focused on organizational commitment, job satisfaction, fit, stress, and career intentions, we develop a more complete picture of factors associated with student entrance into STEM disciplines, continuance through educational and training programs, and entry into the STEM workforce.