The U.S. Preventive Services Task Force recommends screening mammography for women, with or without clinical breast examination, every 1 to 2 years for women ages 40 and older.
U.S. Preventive Services Task Force. Breast Cancer: Screening recommendation statement [Internet]. 2009 Nov [cited 2014 Jan 8]. Available from: http://www.uspreventiveservicestaskforce.org/uspstf09/breastcancer/brcanrs.htm