The U.S. Preventive Services Task Force proposed that people assigned female at birth with average risk of breast cancer should start screening at age 40. Based on evidence of a rising occurrence of breast cancer among people under 50, lowering the age may help with early detection and treatment.

Breast cancer is the second leading cause of death among all women in the U.S. (CDC). 

The recommendation will save more women's lives because of earlier detection, particularly Black women who are 40% more likely to die from breast cancer (University of Chicago Medicine).

An estimated 12.9% of women born in the U.S. today will develop breast cancer at some time in their lives (National Cancer Institute).

It is important to discuss risk factors, including family history, with a doctor. People with “average risk” include those who do not have a personal or family history of breast cancer; do not have a genetic mutation known to increase risk (such as a BRCA gene); and have not had chest radiation therapy before age 30 (American Cancer Society). 

There is still a lack of consensus about whether to screen annually or once every two years.  

Experts are still learning about potential cancer risk factor exposures in early life and/or young adulthood, and why some groups may be more at risk than others.