Purpose: This study aims to focus on the experiences of biomedical science students nearing the end of their doctoral programs and the factors that influence their well-being. In addition to identifying general challenges, the study aims to expand understanding of how interactions with principal investigators (PIs) can influence students' well-being and engagement in wellness practices. Design/methodology/approach: This qualitative study presents an analysis of interview data collected from 90 trainees five years after beginning their graduate programs. All were participants in a larger mixed-methods, longitudinal study. Emergent themes and a codebook were established after reviewing interview transcripts and completing memos. Codes were applied to data, and reports were generated to confirm and challenge early interpretations. Findings: Participants described four key factors that influenced their well-being: perceived work/life balance; managing progress on research; program completion and job search; and overall faculty relationships. While relationships with PIs could be a source of stress, participants more often described how both interactions with, and observations of their PIs could amplify or mitigate their ability to manage other stressors and overall sense of well-being. Originality/value: While researchers in the USA have increasingly considered the factors impacting graduate student mental health, there has been less of an emphasis on wellness and well-being. Furthermore, there has been less attention to how PIs contribute, in positive and negative ways, to these outcomes. This study offers insight into well-being at a specific timepoint, considering dynamics unique to wellness and well-being in the later stages of doctoral training.