Mary Masterson has spent nearly three decades in the emergency department at Johns Hopkins Bayview Medical Center (Bayview) in Baltimore, Maryland. She joined Bayview’s ED in 1997, the same year she earned her PA certification, and has since moved through clinical practice, education, informatics, and hospital governance while still practicing at the bedside. She currently serves as the Program Director for the Emergency Medicine PA Residency, Assistant Manager for Advanced Practice (EM), Chair Emeritus for the JHBMC Advanced Practice Advisory Council, co-founder of the JHM Emergency Medicine APP Leadership Collaborative, and Epic Exemplar.

In 2007 Mary co-directed the first Emergency Medicine PA postgraduate residency within Johns Hopkins Medicine, and the first Advanced Practice residency at Bayview and has directed the program since 2017. She helped develop the 18-month curriculum and continues to revise, update, and improve the curriculum to keep up with current emergency medicine education. Mary has additional expertise in development and implementation of telemedicine and telescreening for the ED as well as Epic design and informatics.

Her clinical and leadership work has been recognized with the 2025 Maryland PA of the Year award from MdAPA, Bayview’s inaugural Advanced Practice Provider of the Year award in 2023, and the Miller-Coulson Award for Clinical Excellence in 2018. She was inducted as a Distinguished Fellow of the American Academy of Physician Associates in 2015 and became a Board-Certified Patient Advocate in 2026. She holds a Master of Physician Assistant Studies from the University of Nebraska, and her published work includes a 2023 review of altered mental status in Physician Assistant Clinics. She lives in Sykesville, Maryland.