On Aug. 9-10, 2017, the American College of Surgeons, under the leadership of its executive director, David M. Hoyt, MD, hosted a Metabolic Surgery Symposium at College Headquarters in Chicago. Walter J. Pories, MD, and I served as co-chairs for this milestone meeting of 27 U.S. surgeons and internists. The purpose of this conclave was to define metabolic surgery and explore its ramifications for ACS membership. To achieve this goal, the 12 formal presentations will be