The unique needs and demands of practicing emergency medicine (EM) necessitate a cognitive framework that differs from the classic hypothetico-deductive model of reasoning taught in the preclinical years of medical school. At its simplest, unlike many other specialties, EM is a bridge to diagnosis and definitive management rather than the destination of diagnosis and definitive management itself. Effective decision-making in the ED, therefore, requires an adaptable but systematic approach that takes into account the undifferentiated nature of patients; the time, resource, and information constraints placed on emergency physicians (EPs); and the ever-changing medicolegal and social landscapes in which EM is being practiced. Clinical inertia is defined as reluctance or delay in changing a diagnosis or treatment plan even in the face of new information or evidence, whether that be escalation, de-escalation, or a complete reversal of therapy.