STEM undergraduates navigate lengthy sequences of prerequisite courses covering volumes of science content. Given that these courses may contribute to attrition and equity gaps in STEM, research is needed to test the assumption that prerequisite content benefits students in their future studies and careers. We investigated the relevance of prerequisite course content for students' careers through semistructured interviews with practicing nurses regarding their undergraduate anatomy and physiology (A&P) courses. Nurses reported that A&P content does not align with the skills and knowledge needed in the nursing profession. Interviewees averaged 39% on a brief A&P assessment, suggesting A&P prerequisites failed to impart a high degree of long-term A&P knowledge among nurses. Further, practicing nurses perceived overcommitment to A&P content coverage as an exclusionary practice that eliminates capable individuals from the prenursing pathway. These findings challenge assumptions surrounding the justification for prerequisite course content and raise questions of whether content expectations actively exclude individuals from STEM or healthcare careers. We aspire for this study to stimulate conversation and research about the goals of prerequisite content, who is best positioned to articulate prerequisite content objectives, and the influence of content coverage on equity and justice in undergraduate STEM education.