Leadership and Administration

Dr. Angela Mills

Angela M. Mills, MD, FACEP
Department Chair

Angela M. Mills, MD is the J. E. Beaumont Professor and Chair of the Department of Emergency Medicine at Columbia University Vagelos College of Physicians and Surgeons as well as the Chief of Emergency Services for the west campus of NewYork-Presbyterian.  A national leader and expert in emergency medicine, Dr. Mills graduated Summa Cum Laude from Muhlenberg College and attended Temple University Medical School where she graduated with Alpha Omega Alpha distinction.

Dr. Mills is a graduate and former Chief Resident of the Emergency Medicine residency program at the University of Pennsylvania. She became a faculty member immediately thereafter at Penn in 2003 and advanced academically being promoted to Professor of Emergency Medicine in 2017. At Penn, Dr. Mills served in several capacities including Medical Director and as the Vice Chair of Clinical Operations. She joined Columbia in February 2018 as the inaugural Chair of the newly formed Department of Emergency Medicine.

Dr. Mills has maintained an active research career where she has focused on emergency diagnostic imaging, undifferentiated abdominal pain, and clinical operations. She has authored over 95 scientific publications and has received research funding from both federal agencies and industry.

Dedicated to combining scholarship with mentoring, Dr. Mills has influenced the careers of numerous junior faculty and trainees. She is strongly committed to education with a teaching style that allows for growth and pursuit of individual research interest. Dr. Mills has been invited to deliver lectures and grand rounds at various national venues and serves on numerous national and local committees and task forces. She is an elected member of the Board of Directors of the Society for Academic Emergency Medicine (SAEM).

Dr. Mills was recently honored with two prestigious awards: the Arnold P. Gold Foundation Humanism in Medicine Award from SAEM and the Mid-Career Award from the Academy for Women in Academic Emergency Medicine. Dr. Mills is a Fellow of the American College of Emergency Physicians.

Dr. Daniel Egan

Daniel Egan, MD
Vice Chair, Education

Dr. Daniel Egan joined the Department of Emergency Medicine in September 2018 as the Vice Chair of Education. In this role, Dr. Egan oversees the educational activities in the department of students, residents, physician assistants and fellows. Dr. Egan is a 2002 graduate of the Icahn School of Medicine at Mount Sinai. He completed his residency training at the Harvard Affiliated Emergency Medicine Residency Program at Brigham and Women’s and Massachusetts General Hospitals where he also served as Chief Resident. Prior to joining Columbia, Dr. Egan was the Residency Program Director at Mount Sinai St. Luke’s Roosevelt and previously served as the Associate Program Director in that training program as well as NYU/Bellevue. Dr. Egan is committed to expanding and innovating education in emergency medicine both within our clinical settings as well as at the medical school.


Dr. Nicholas Gavin

Nicholas Gavin, MD, MBA, MS
Vice Chair, Clinical Operations

Dr. Nicholas Gavin joined the Columbia University Department of Emergency Medicine as Vice Chair of Clinical Operations in January 2019. In this role, he oversees operations at the four NewYork-Presbyterian/Columbia EDs: Columbia University Irving Medical Center, Morgan Stanley Children’s Hospital of New York, Allen Hospital and Lawrence Hospital. Dr. Gavin received both his undergraduate and medical school degrees from NYU and completed his emergency medicine residency at Alameda County Medical Center in Oakland, California where he served as Chief Resident. From 2013 to 2018, Dr. Gavin served as a faculty member of the Department of Emergency Medicine at NYU/Bellevue and from 2015 to 2018, led the NYU Langone Hospital-Brooklyn Emergency Department as Chief of Service. In 2019, Dr. Gavin completed the Cornell University Executive MBA/MS program in Healthcare Leadership.

Dr. Gavin is interested in advancing emergency care as a driver of high quality hospital-based care, as well as a contributor to the broader community’s health.

Dr. David Kessler

David Kessler, MD, MSc
Vice Chair, Innovation

Dr. David Kessler is the Vice Chair of Innovation & Strategic Initiatives in the Department of Emergency Medicine at Columbia University. As Vice Chair of Innovation, Dr. Kessler fosters a culture of innovation and collaboration within the department to help implement novel programs and innovative solutions to complex adaptive systems problems. He is a graduate of Princeton University and Mount Sinai School of Medicine, where he completed his pediatric residency on the global health track. Dr. Kessler completed his Pediatric Emergency Medicine Fellowship and Emergency Ultrasound training at Bellevue Hospital in Manhattan, NY, and his Master of Science in Clinical Investigation at New York University. In 2011, he joined the faculty at Columbia University Irving Medical Center as the Director of Operations of Pediatric Emergency Medicine. Since then, he has helped create several novel programs, such as a curriculum for interprofessional clinical simulation and the fellowship in pediatric emergency ultrasound. Through his role as an Associate Medical Director for the Mary & Michael Jaharis Simulation Center, Dr. Kessler helps other departments start new safety-driven simulation programs.

As a founder and director for INSPIRE, (International Network for Simulation-based Pediatric Innovation, Research, and Education), Dr. Kessler is committed to growing a community of practice dedicated to collaboration, mentorship, and scholarship.

Dr. Penelope Lema

Penelope C. Lema, MD
Vice Chair, Faculty Affairs

Dr. Penelope Lema joined the Department of Emergency Medicine in February 2019 as the Vice Chair of Faculty Affairs and Associate Professor of Emergency Medicine at Columbia University Vagelos College of Physicians and Surgeons. Her dual role is to lead as the Emergency Ultrasound Division Director for the Columbia's Emergency Departments.  Dr. Lema moved back to NYC, her hometown, after residing in Western NY for the past 8 years where she most recently served as the Director of the Emergency Ultrasound Division and Fellowship at the University at Buffalo. Dr. Lema has been a leader in Emergency Ultrasound for over 12 years and was previously the Emergency Ultrasound Director at the University of Rochester (2011 - 2013) and New York Presbyterian Queens (2007 - 2011).  

She received her medical school degree from SUNY Stony Brook School of Medicine and completed her Emergency Medicine Residency and Emergency Ultrasound Fellowship at Northshore University Hospital (currently Hofstra Northwell), where she was elected Chief Resident.

Dr. Lema is a passionate educator, dedicated to faculty professional development and equity in medicine.  She is an avid advocate of the specialty of Emergency Medicine and access to care.  

Dr. Marie Romney

Marie-Laure Romney, MD, MBA
Vice Chair, Quality & Patient Safety

Dr. Marie-Laure Romney joined the Department of Emergency Medicine as Vice Chair of Quality and Patient Safety in November of 2018.  In this role, Dr. Romney oversees quality for the Department’s four ED sites and telemedicine program.  Dr. Romney completed her residency training in Emergency Medicine at NYU Langone Medical Center/Bellevue Hospital Center and an Emergency Ultrasound Fellowship at SUNY Downstate Medical Center. She holds an undergraduate degree from Cornell University, a medical degree from Robert Wood Johnson Medical School, and an MBA from the Wharton School at the University of Pennsylvania.  She is also an alumna of the Clinical Quality Fellowship Program (CQFP), sponsored by the Greater New York Hospital Association (GNYHA) and the United Hospital Fund (UHF).  Prior to joining the team at Columbia, Dr. Romney served as Director of Quality, Continuous Improvement and Patient Safety in the Department of Emergency Medicine at Kings County Hospital.

As a TeamSTEPPS Master Trainer with Lean Management Silver Certification, Dr. Romney enjoys leading interdisciplinary teams to drive meaningful change to help improve healthcare delivery.

Dr. Bernard Chang

Bernard P. Chang, MD, PhD
Vice Chair, Research

Dr. Bernard P. Chang is the Vice Chair of Research in the Department of Emergency Medicine at Columbia University. A practicing emergency physician and research psychologist, he is a national leader and expert on neurological and psychiatric emergencies, with interests in the psychological and physiological effects of stress in both patients and clinicians. Dr. Chang has received grant funding at the institutional, state, and federal level, and was one of the youngest faculty in the history of Emergency Medicine to be awarded an independent federal grant (R01). Dr. Chang received his PhD from Harvard in psychology, his MD from Stanford and completed his Emergency Medicine residency training at the Harvard Affiliated Emergency Medicine Residency at Massachusetts General Hospital and Brigham and Women’s Hospital. Prior to medical school he served as a sailboat captain doing boat deliveries internationally.

Dr. Meri Sonnett

F. Meridith Sonnett, MD
Chief, Division of Pediatrics

Dr. Meridith Sonnett joined Columbia in 1995 and is an Associate Professor of Pediatrics in the Department of Emergency Medicine at the Columbia University Vagelos College of Physicians and Surgeons, and Chief of the Division of Pediatric Emergency Medicine at the New York Presbyterian Morgan Stanley Children’s Hospital. She received her MD degree from the State University of New York at Buffalo, and completed Pediatric Residency training and Pediatric Emergency Medicine Fellowship training at Montefiore Medical Center, Albert Einstein College of Medicine and the Jacobi Medical Center. Dr. Sonnett was awarded a certificate from the Harvard T.H. Chan School of Public Health for invited participation in the Chiefs of Clinical Service Leadership Program.

Dr. Sonnett has been a leader in the field for over 25 years and is recognized for her greatest accomplishment in establishing and developing a nationally renowned Division of Academic Pediatric Emergency Medicine here at Columbia. She is actively involved in ED Operations, and is a strong, supportive advocate for promoting faculty professional development.

Dr. Sonnett’s primary academic focus is in the area of quality and performance improvement and she serves as the chair of the MSCHONY Department of Pediatrics Quality Council. Dr. Sonnett has been the leader of multiple quality improvement initiatives both within the Division of Pediatric Emergency Medicine and the Department of Pediatrics. She has been actively involved in both federally funded and foundation funded clinical research, and has been the principal investigator or co-investigator on numerous multicenter collaborative research projects.

Dr. Sonnett is a long-standing Fellow of the American Academy of Pediatrics, and a Fellow of the American College of Emergency Physicians.

D. Anne Stewart

D. Anne Stewart, MPA
Department Administrator/CFO

D. Anne Stewart is the Department Administrator/CFO to the Department of Emergency Medicine. She possesses over twenty-five years of progressive experience in academic healthcare. This includes management and oversight of finance, operations, human resources and capital projects, cultivation of client/staff/donor relationships and improving customer service standards.

Prior to joining the Department of Emergency Medicine, D. Anne was the Department Administrator/CFO to the Department of Urology and interim Department Administrator to the Department of Dermatology at Columbia University Medical Center. She began her career in healthcare management at Weill Cornell where she held leadership roles in the Departments of Medicine and Surgery.

D. Anne received her MPA at Baruch College - Zicklin School of Business and is an active member of numerous CUMC and FPO committees, including the Access & Patient Satisfaction Committee and the P&S Staff Diversity Council.

To foster her passion for mentorship and leadership development, D. Anne became a Certified Life Coach and is currently pursuing her M.Ed at Teachers College in Counseling Psychology.