Despite extensive efforts to increase the number of undergraduates majoring and persisting in science, math, engineering, and technology (STEM) fields, there is surprisingly little understanding of recent patterns of switching from these majors to those in other fields of study. In addition, little is known about whether the racial, class, and gender dimensions to these patterns are unique to STEM fields or part of a process that affects majors in other fields across the higher education system. This working paper uses theoretically driven logistic regression models to examine these questions using the 2004/2009 cohort of undergraduate students from the Beginning Postsecondary Student Longitudinal Study (BPS:04/09). Results point to gender, race, and class-based disparities in patterns of switching majors that are unique to STEM fields, indicating that these disciplines are sites of ongoing struggles for proponents of equity in higher education and workforce development. The following are appended: (1) Appendix Table 1--Descriptive Statistics for Beginning Postsecondary Students who Began their Postsecondary Education in a Bachelor's Program (N = 5,200); and (2) Appendix Table 2--Variable Descriptions.