The American College of Physicians updated its guidance on breast cancer screening for asymptomatic, average-risk adult females, synthesizing high-quality evidence from three major guidelines (USPSTF, ECIBC, and CTFPHC). The core finding is that screening benefits most clearly outweigh harms in women aged 50–74, while the evidence is more nuanced for younger and older age groups. The guidelines emphasize biennial mammography as the preferred interval, shared decision-making for edge-case populations, and a conservative approach to supplemental imaging in women with dense breasts.