Approximately 30% of women will experience abnormal uterine bleeding (AUB) during their life time. Previous terms defining AUB have been confusing and imprecisely applied. As a consequence, both clinical management and research on this common problem have been negatively impacted. In 2011, the International Federation of Gynecology and Obstetrics (FIGO) Menstrual Disorders Group (FMDG) published PALM-COEIN, a new classification system for abnormal bleeding in the reproductive years. Terms such as menorrhagia, menometrorrhagia, metrorrhagia, dysfunctional uterine bleeding, polymenorrhea, oligomenorrhea, and uterine hemorrhage are no longer recommended. The PALM-COEIN system was developed to standardize nomenclature to describe the etiology and severity of AUB. A brief description of the PALM-COEIN nomenclature is presented as well as treatment options for each etiology. Clinicians will frequently encounter women with AUB and should report findings utilizing the PALM-COEIN system.