Women aged 75 and older are the fastest growing segment of the US population and breast cancer incidence increases with age. However, none of the randomized trials of mammography screening included women >74 years and it is not known if mammography helps these women live longer. Increasingly, data suggest that women need around 10 year life expectancy to have a chance at a mortality benefit from being screened with mammography. Meanwhile, there are immediate harms to screening older women including: pain, anxiety, complications from tests after a false positive mammogram (e.g., breast biopsy), and overdiagnosis (finding tumors that otherwise would never have caused symptoms in one's lifetime). Overdiagnosis is particularly concerning since some older women experience significant complications from breast cancer treatment. Guidelines state that there is insufficient evidence to recommend mammography screening for women aged 75 years or older and encourage clinicians to discuss the uncertainty about the balance of benefits and harms with older women. Yet, few older women are informed of potential harms of mammography before being screened, likely because explaining such uncertainty can be challenging and time consuming.