This report attempts to examine the preparation for calculus on a microscopic level. Researchers tracked the actual enrollment of students in precalculus, calculus, and non-calculus based courses over 20 successive semesters, from fall 1992 to spring 2002. This report is also an examination of the probable success of the calculus preparation curricula. Citation: Dunbar, S. (2006). Enrollment Flow to and from Courses Below Calculus. In N. Hastings (Ed.), A Fresh Start for Collegiate Mathematics: Rethinking the Courses Below Calculus (pp. 28-42). Mathematical Association of America.