Emergency Medicine has a scientifically derived and commonly accepted description of the domain of its clinical practice. That document, The Model of the Clinical Practice of Emergency Medicine (EM Model), was developed through the collaboration of six organizations: the American Board of Emergency Medicine (ABEM), the administrative organization for the project, the American College of Emergency Physicians (ACEP), the Council of Emergency Medicine Residency Directors (CORD), the Emergency Medicine Residents' Association (EMRA), the Residency Review Committee for Emergency Medicine (RRC-EM), and the Society for Academic Emergency Medicine (SAEM). Development of the EM Model was based on an extensive practice analysis of the specialty. The practice analysis relied on both empiric data gathered from actual emergency department visits and several expert panels. The resulting product was first published in 2001, and has successfully served as the common source document for all emergency medicine organizations. One of its strengths is incorporating the reality that emergency medicine is a specialty driven by symptoms not diagnoses, requiring simultaneous therapeutic and diagnostic interventions. The task force that developed the EM Model recommended that a new task force, composed of representatives from all six organizations, be formed every 2 years to assess the success of the document in accomplishing its objective of supporting the ongoing development of the specialty of emergency medicine; to consider alterations to the EM Model suggested by the collaborating organizations; and to recommend changes to the six sponsoring organizations. The initial 2-year review occurred in 2003, with representatives from each of the six organizations suggesting changes and reporting how their respective organizations had used the document. The initial 2-year update was published in Annals of Emergency Medicine and Academic Emergency Medicine in 2005. Subsequently, a task force met every 2 years to review the EM Model and recommend changes. In 2013, a seventh organization, the American Academy of Emergency Medicine (AAEM), was added as a collaborating organization. In 2014, the collaborating organizations made the decision to review the EM Model on a 3-year review cycle, beginning in 2016. The 2016 update was published in Journal of Emergency Medicine in 2017. In 2019, the AAAEM Resident and Student Association was added as an eighth collaborating organization. This article provides a brief review of the original EM Model, along with the changes to the EM Model as recommended by the 2019 EM Model Review Task Force. Significant changes occurred with the 2019 review, including the addition of oncologic emergencies in the newly renamed “Category 8, Hematologic and Oncologic Disorders.” A summary of all 2019 changes and an update on current uses of the EM Model by the seven collaborating EM organizations are also included in this article.