Objective: The development of these updated clinical practice guidelines (CPG) was commissioned by the American Association of Clinical Endocrinologists, The Obesity Society, the American Society of Metabolic and Bariatric Surgery, the Obesity Medicine Association, and the American Society of Anesthesiologists boards of directors in adherence to the American Association of Clinical Endocrinologists 2017 protocol for standardized production of CPG, algorithms, and checklists., Methods: Each recommendation was evaluated and updated based on new evidence from 2013 to the present and subjective factors provided by experts., Results: New or updated topics in this CPG include contextualization in an adiposity-based, chronic disease complications-centric model, nuance-based, and algorithm/checklist-assisted clinical decision-making about procedure selection, novel bariatric procedures, enhanced recovery after bariatric surgery protocols, and logistical concerns (including cost factors) in the current healthcare arena. There are 85 numbered recommendations that have updated supporting evidence, of which 61 are revised and 12 are new. Noting that there can be multiple recommendation statements within a single numbered recommendation, there are 31 (13%) Grade A, 42 (17%) Grade B, 72 (29%) Grade C, and 101 (41%) Grade D recommendations. There are 858 citations, of which 81 (9.4%) are evidence level (EL) 1 (highest), 562 (65.5%) are EL 2, 72 (8.4%) are EL 3, and 143 (16.7%) are EL 4 (lowest)., Conclusions: Bariatric procedures remain a safe and effective intervention for higher-risk patients with obesity. Clinical decision-making should be evidence-based within the context of a chronic disease. A team approach to perioperative care is mandatory with special attention to nutritional and metabolic issues., Competing Interests: Disclosures Chair of the Task Force: Jeffrey I. Mechanick, M.D., M.A.C.E.: Abbott Nutrition, honoraria for lectures and program development. Co-Chairs of the Task Force: Caroline Apovian, M.D.: Orexigen, GI Dynamics, Takeda, Nutrisystem, Zafgen, Sanofi-Aventis, Novo Nordisk, Scientific Intake, Xeno Biosciences, Rhythm Pharmaceuticals, Eisai, EnteroMedica, Bariatrix Nutrition, consultant; Gelesis and Science-Smart LLC, stock options; Aspire Bariatrics, Myos, the Vela Foundation, the Dr. Robert C. and Veronica Atkins Foundation, Coherence Lab, Energesis, Gelesis, Orexigen, GI Dynamics, Takeda, Novo Nordisk, PCORI, research grant support. Stacy Brethauer, M.D., Medtronic, speaker. W. Timothy Garvey, M.D., F.A.C.E., Merck, Novo Nordisk, American Medical Group Association, BOYDSense, Sanofi, Gilead, Amgen, Abbott Nutrition, National Diabetes and Obesity Research Institute, diaTribe Foundation, consultant; IONIS, Novartis, Bristol-Myers-Squibb, Pfizer, Merck, Lilly, stock; Sanofi, Novo Nordisk, Pfizer, research grant support. Aaron M. Joffe, D.O., F.C.C.M., American Society of Anesthesiologists, speaker. Robert F. Kushner, M.D., Novo Nordisk, Retrofit, Weight Watchers, consultant. Richard Lindquist, M.D., F.A.A.S.P., Seca scales, Metagenics/Bariatric Advantage, Livongo/Retrofit, consultant; Novo Nordisk Orexigen, speaker. Rachel Pessah-Pollack, M.D., F.A.C.E., Boehringer Ingelheim, Eli Lilly, Radius, consultant and advisor. Richard D. Urman, M.B.A., M.D., C.P.E., 3M, Sandoz, consulting fees; Merck, Medtronic, research grant support. Julie Kim, M.D. and Jennifer Seger, M.D., report no potential conflicts of interest. Task Force Members: Shanu Kothari, M.D., F.A.C.S., F.A.S.M.B.S., Ethicon, Lexington Medical, consultant; Gore Medical, speaker. Michael V. Seger, M.D., F.A.C.S., F.A.S.M.B.S., Obalon Therapeutics, consultant and speaker. Christopher D. Still, D.O., F.A.C.N., F.A.C.P., Novo Nordisk, speaker; Ethicon-Endosurgery, research grant support. M. Kathleen Figaro, M.S., M.D., F.A.C.E., Novo Nordisk, Boehringer Ingelheim, speaker. Stephanie Adams, Ph.D., John B. Cleek, M.D., Karen Flanders, M.S.N., C.N.P., C.B.N. Jayleen Grams, M.D., Ph.D., Daniel L. Hurley, M.D., F.A.C.E., and Riccardo Correa, M.D., F.A.C.E., report no potential conflicts of interest. Reviewers: Michael A. Bush, M.D., F.A.C.E., Eli Lilly, Novo Nordisk, Sanofi, Boehringer Ingleheim, Janssen, AstraZeneca, speaker. Dace L. Trence, M.D., F.A.C.E., Medtronic, Sanofi, stock ownership. Scott Isaacs, M.D., F.A.C.P., F.A.C.E. and Ann M. Rogers, M.D., F.A.C.S., report no potential conflicts of interest. Note: Reference sources are followed by an evidence level [EL] rating of 1, 2, 3, or 4., (Copyright © 2019. Published by Elsevier Inc.)