Dr. Marsteller has been involved in health services research since 1993 and specializes in organizational behavior and theory, specifically in estimating the influence of organizational variables and contextual measures on quality improvement activities in learning organizations. She focuses her research on the determinants of successful implementation, dissemination, and sustainability of knowledge. She conducts mixed methods research in both inpatient and ambulatory health care settings.

She is jointly appointed in the Johns Hopkins School of Medicine's Department of Anesthesia and Critical Care Medicine in the Armstrong Institute for Patient Safety and Quality, where she leads the Research Facilitation Council, and at the Johns Hopkins Carey Business School. She also serves as an Associate Director of the Center for Health Service and Outcomes Research and as the co-leader of the Behavioral, Social and Systems Science Translational Research Community within the Institute for Clinical and Translational Research.