To date, anticoagulation practices in CPB have not been standardized in accordance with the evidence base. This clinical practice guideline was written with the intent to ll the evidence gap and to establish best practices in anti- coagulation therapy for CPB using the available evidence. To identify relevant evidence, a systematic review was outlined and literature searches were conducted in PubMed using standardized medical subject heading (MeSH) terms from the National Library of Medicine list of search terms. Search dates were inclusive of January 2000 to December 2015. The search yielded 833 abstracts, which were reviewed by two independent reviewers. Once accepted into the full manuscript review stage, two members of the writing group evaluated each of 286 full papers for inclusion eligibility into the guideline docu- ment. Ninety-six manuscripts were included in the nal review. In addition, 17 manuscripts published before 2000 were included to provide method, context, or addi- tional supporting evidence for the recommendations as these papers were considered sentinel publications. Members of the writing group wrote and developed recommendations based on review of the articles ob- tained and achieved more than two thirds agreement on each recommendation. The quality of information for a given recommendation allowed assessment of the level of evidence as recommended by the American College of Cardiology Foundation/American Heart Association Task *These clinical practice guidelines (CPGs) were developed prior to the publication of The American Association for Thoracic Surgery/Society of Thoracic Surgeons Position Statement on Developing Clinical Practice Documents (Bakaeen, et al. Ann Thorac Surg 2017;103:1350 6), and thus their development did not strictly adhere to the process for CPGs outlined in that document. Nevertheless, these CPGs were the product of a lengthy and rigorous review by a multidisciplinary panel of experts, and approved by all three participating societies. 