In Reply Our recent Editorial1 commented on findings that 81% of surveyed physicians recommended routine screening mammography to women without a personal or family history of breast cancer starting at age 40 years.2 We found this disappointing, given that the evidence of benefit in women ages 40 to 49 years is weak, but the harms of screening are substantial. Drs Kopans and Baker, both mammographers, disparage our view and claim that we misreported the recommendations of the US Preventive Services Task Force (USPSTF) and American Cancer Society. We correctly state that neither the USPSTF nor the nor American Cancer Society recommend routine breast cancer screening among women between the ages of 40 and 45 years.3,4 Both Drs Kopans and Baker bend the meaning of official guidelines statements, for example, stating that the American Cancer Society recommends screening beginning at age 40 years because the recommendation says that “women should have the opportunity to begin annual screening between the ages of 40 and 44 years.”4(p1599)