Indiana University-Purdue University Indianapolis (IUPUI) / Background. Traditionally, departmental appointment type (basic science or clinical) and/or degree earned (PhD, MD, or MD-PhD) have served as proxies for how we conceptualize clinical and basic science faculty. However, the landscape in which faculty work has considerably changed and now challenges the meaning of these cohorts. Within this context I introduce a behavior-based role variable that is defined by how faculty spend their time in four academic activities: teaching, research, patient care, and administrative duties. Methods. Two approaches to role were compared to department type and degree earned in terms of their effects on how faculty report their perceptions and experiences of faculty vitality and its related constructs. One approach included the percent of time faculty spent engaged in each of the four academic activities. The second approach included role groups described by a time allocation rubric. This study included faculty from four U.S. medical schools (N = 1,497) and data from the 2011 Indiana University School of Medicine Faculty Vitality Survey. Observed variable path analysis evaluated models that included traditional demographic variables, the role variable, and faculty vitality constructs (e.g., productivity, professional engagement, and career satisfaction). Results. Role group effects on faculty vitality constructs were much stronger than those of percent time variables, suggesting that patterns of how faculty distribute their time are more important than exactly how much time they allocate to single activities. Role group effects were generally similar to, and sometimes stronger than, those of department type and degree earned. Further, the number of activities that faculty participate in is as important a predictor of how faculty experience vitality constructs as their role groups. Conclusions. How faculty spend their time is a valuable and significant addition to vitality models and offers several advantages over traditional cohort variables. Insights into faculty behavior can also show how institutional missions are (or are not) being served. These data can inform hiring practices, development of academic tracks, and faculty development interventions. As institutions continue to unbundle faculty roles and faculty become increasingly differentiated, the role variable can offer a simple way to study faculty, especially across multiple institutions.