Description: The purpose of this guidance statement is to provide advice to clinicians on breast cancer screening in average-risk women based on a review of existing guidelines and the evidence they include. Methods: This guidance statement is derived from an appraisal of selected guidelines from around the world that address breast cancer screening, as well as their included evidence. All national guidelines published in English between 1 January 2013 and 15 November 2017 in the National Guideline Clearinghouse or Guidelines International Network library were included. In addition, the authors selected other guidelines commonly used in clinical practice. Web sites associated with all selected guidelines were checked for updates on 10 December 2018. The AGREE II (Appraisal of Guidelines for Research and Evaluation II) instrument was used to evaluate the quality of guidelines. Target Audience and Patient Population: The target audience is all clinicians, and the target patient populatio