Racially minoritized students in the United States constitute 30% of the U.S. population, but students from these populations represent a smaller proportion of those who earn science, technology, engineering, and mathematics (STEM) undergraduate degrees. This disproportionality contributes to race/ethnic income, status, and power inequalities linked to STEM careers. Using a combination of vote counting and narrative approaches, the authors synthesize 50 recent articles about the factors related to college students' STEM participation. Consistent with cumulative disadvantage and critical race theories, findings reveal that the disproportionality of racially minoritized students in STEM is related to their inferior secondary school preparation; the presence of racialized lower quality educational contexts; reduced levels of psychosocial factors associated with STEM success; less exposure to inclusive and appealing curricula and instruction; lower levels of family social, cultural, and financial capital that foster academic outcomes; and fewer prospects for supplemental STEM learning opportunities. Policy implications of findings are discussed.