The fastest growing supply of jobs in the United States today is in Science, Technology, Engineering, and Mathematics (STEM) fields. Yet despite the availability of work in STEM, there is not a sufficient supply of workers to fill open positions. Amidst the growing demand for STEM workers, educational achievement and attainment in STEM fields in the United States are moving in the opposite direction. The achievement of secondary school students in mathematics and science is declining, with less than one-third of U.S. eighth graders now proficient in these subjects; there is a concurrent decline in interest in STEM fields among many middle and high school students (PCAST, 2010). Equally troubling, 60 percent of all college students and more than 75 percent of Black and Latino college students who indicate initial interest in pursuing STEM fields do not persist to the point of earning a STEM degree (PCAST, 2010). An important policy question to consider is what role, if any, financial barriers play in dissuading students from pursuing or completing college study in STEM disciplines. In this paper, the authors offer new evidence of the impact of need-based financial aid on whether students pursue and complete courses and degrees in STEM fields. Their analysis focuses on Florida high school graduates in the 1999-2000 academic year who submitted a Free Application for Federal Student Aid (FAFSA) application, whose Expected Family Contribution (EFC) falls between $590 and $2,590, and who demonstrate readiness for postsecondary study in STEM disciplines. Four tables are appended.