Longitudinal qualitative research (LQR) is an emerging methodology in healthcare and health professions education research that focuses on change in complex, dynamic transitions, and processes as that change unfolds. This approach allows for in-depth exploration of personal and professional transitions, developmental processes, and evolution in how individuals make sense of experiences and events. In this Methodological Progress Note, we define the key features of LQR, distinguish LQR from other qualitative methodologies, and present a case for longitudinal qualitative work to offer a lens of time that might illuminate gaps in the field of hospital medicine.