Chair
ChairMark R. Chassin, M.D., F.A.C.P., M.P.P., M.P.H.
The American Board of Surgery (ABS), the national certifying body for general surgeons and related specialists, is pleased to welcome Dr. Mark R. Chassin as chair for 2026-2027.
Dr. Chassin has served on the ABS Board of Directors for the last seven years since his election to the governing board of the ABS following the organization’s governance redesign in 2019.
“Dr. Chassin’s unique combination of a professional lifetime devoted to improving quality and safety in medicine as well as his deeply seasoned leadership experience has served the ABS and the profession of surgery for many years,” said ABS President and CEO Dr. Jo Buyske. “It is an honor and a privilege to have him as chair.”
Dr. Chassin is considered one of the world’s leading experts in healthcare quality, patient safety, and process improvement. During his 14-year tenure as president and CEO of The Joint Commission, he:
- Led the organization to major worldwide growth in the number of accredited organizations
- Directed the development of rigorous documentation of accreditation’s positive impacts on healthcare quality
- Oversaw a turnaround in the organization’s financial performance
- Introduced the concepts of high reliability and zero harm to the health care industry
- Created programs that offered tools, strategies, and training for healthcare organizations to progress toward high reliability
In 2022, Dr. Chassin’s work was recognized with the John M. Eisenberg Honorary Lifetime Achievement Award.
“I am profoundly honored and humbled that the ABS Board of Directors has chosen me to be its chair for the coming year. I look forward to working closely with my colleagues on the Board and throughout the organization to advance the vital mission of the American Board of Surgery.”
Prior to his role at The Joint Commission, Dr. Chassin was the Edmond A. Guggenheim Professor of Health Policy and founding chairman of the Department of Health Policy at the Mount Sinai School of Medicine and Executive Vice President for Excellence in Patient Care at Mount Sinai Medical Center in New York. During his time at Mount Sinai Medical Center, he established a nationally recognized quality improvement program and an NIH-funded research center aimed at studying and alleviating racial and ethnic healthcare disparities. He also served as the commissioner of the New York State Department of Health.
Dr. Chassin received his undergraduate and medical degrees from Harvard University and holds master’s degrees in public policy and public health from the Kennedy School of Government at Harvard and the University of California at Los Angeles, respectively. He is a member of the National Academy of Medicine of the National Academy of Sciences and was selected in the first group of honorees as a lifetime member of the National Associates of the National Academies. He has authored or co-authored more than one hundred peer-reviewed publications and has been invited to speak to audiences around the world on various topics related to healthcare quality and patient safety. As a member of the IOM Committee on Quality of Health Care in America, Dr. Chassin co-authored the landmark “To Err Is Human” report in 2000.
Vice Chair
Vice ChairJohn H. Stewart, IV, M.D., M.B.A.
Dr. John H. Stewart will be serving as vice chair of the ABS for the 2026-2027 term, succeeding Dr. Mark R. Chassin.
Nominated to the ABS by the American College of Surgeons in 2018, Dr. Stewart served on the Complex General Surgical Oncology Board of the ABS and on the Research Committee of the ABS Council. He also led the ABS Diversity, Equity, and Inclusion Task Force from 2020 to 2021, resulting in the creation of the Diversity, Equity, and Inclusion Committee of the ABS Council in 2022.
“It is a tremendous honor to serve as vice chair of the American Board of Surgery. This role represents an opportunity to help shape the standards that define excellence in our profession, while ensuring that the surgeons we certify reflect the full talent and diversity of the patients we serve. I’m especially energized by the chance to advance equity and access within surgical training and certification, work that has been central to my career and that I believe strengthens the entire field.”
Dr. Stewart is a nationally recognized surgeon-scientist and leader in education, research, and cancer care who currently serves as chair of the department of surgery and associate dean of oncological programs for Morehouse School of Medicine (MSM), and chief of surgery for MSM at Grady Health System in Atlanta, Ga. His research interests include developmental oncoimmunotherapeutics, surgical oncology, clinical trials, artificial intelligence in healthcare, delivery of cancer therapy to underserved populations, and healthcare policy, strategy, and operations
Originally from Shreveport, La., he obtained his medical degree at Howard University College of Medicine before completing residency at Temple University Hospital and Vanderbilt University Hospital, and fellowships in tumor immunotherapy and surgical oncology at the National Cancer Institute. He also holds a Master of Business Administration degree from Wake Forest University. In 2023, he received the Howard University College of Medicine Distinguished Alumni Award.
Dr. Stewart served as chair of the Finance Committee of the ABS Board of Directors, as President-Elect of the Southeastern Surgical Congress, and as the immediate past president of the Society of Black Academic Surgeons, for which he also served as treasurer. He has also held leadership roles in several other nationally recognized surgical societies including chair of the ACS Advisory Council for General Surgery and member of the Halsted Society Board of Directors.
About the ABS
The American Board of Surgery is an independent, nonprofit organization founded in 1937 for the purpose of certifying individuals who have met a defined standard of education, training and knowledge in the field of surgery. Surgeons certified by the ABS have completed at least five years of surgical training following medical school and successfully completed a written and oral examination process administered by the ABS. They must then maintain their board certification through ongoing learning and practice improvement activities.
The ABS offers board certification in general surgery, vascular surgery, pediatric surgery, surgical critical care, and complex general surgical oncology. It is one of the 24 member boards of the American Board of Medical Specialties.
July 1, 2026 |