<i>This paper examines the phenomenology of diagnostic crossover in eating disorders, the movement within or between feeding and eating disorder subtypes or diagnoses over time, in two young women who experienced multiple changes in eating disorder diagnosis over 5 years. Using interpretative phenomenological analysis, this study found that transitioning between different diagnostic labels, specifically between bulimia nervosa and anorexia nervosa binge/purge subtype, was experienced as disempowering, stigmatizing, and unhelpful. The findings in this study offer novel evidence that, from the perspective of individuals diagnosed with EDs, using BMI as an indicator of the presence, severity, or change of an ED may have adverse consequences for well-being and recovery and may lead to mischaracterization or misclassification of health status. The narratives discussed in this paper highlight the need for more person-centered practices in the context of diagnostic crossover. Including the perspectives of those with lived experience can help care providers working with individuals with eating disorders gain an in-depth understanding of the potential personal impact of diagnosis changing and inform discussions around developing person-focused diagnostic practices.</i>