ABSTRACT: Menstrual flow outside of normal volume, duration, regularity, or frequency is considered abnormal uterine bleeding (AUB). One third of outpatient visits to the gynecologist are for AUB, and it accounts for more than 70% of all gynecologic consults in the perimenopausal and postmenopausal years 1. Many new diagnostic modalities are available to assist the clinician in evaluating the woman with alterations in her normal menstrual patterns. The purpose of this document is to provide evidence-based management guidelines for the evaluation of the reproductive-aged patient with AUB. A secondary purpose is to introduce a new classification system for AUB. This document does not address pregnancy-related bleeding or postmenopausal bleeding.