In 2002, the U.S. Preventive Services Task Force (USPSTF) recommended screening mammography every 1 to 2 years for all women 40 or older. In a 2009 update, the task force has revised its guidelines based on: 1) a systematic review of the benefits and harms of screening; and 2) statistical modeling to estimate outcomes associated with annual versus biennial screening that begins and ends at different ages.
The USPSTF now recommends against routine screening of younger women (age range, 40–49). Decisions about screening women younger than 50 should be individualized. C recommendation (The USPSTF recommends against routinely providing the service; the grading system can be accessed on the USPSTF website.) The task force recommends biennial screening mammography for all middle-aged women (age range, 50–74). B recommendation (The USPSTF recommends the service.) However, current evidence is insufficient to assess the benefits and harms of screening mammography in older women (age, 75 [I statement]).
The task force also found that current evidence is insufficient to assess the benefits and risks of clinical breast examination that is performed in addition to mammography in women age 
40 (I statement), as well as to assess benefits and harms of digital mammography or magnetic resonance imaging compared with film mammography. (I statement) Teaching women to perform breast self-examination is now discouraged.
D recommendation (The USPSTF recommends against the service.)
