Mammograms at 40: What Changed and Why It Matters

January 27, 2026

Evolution of Breast Imaging

For decades, mammograms have been one of the most powerful tools for detecting breast cancer early and saving lives. National guidelines have gradually shifted: once recommending routine screening starting at age 60, then lowering it to 50, and now to 40. But why the change?

This shift reflects growing evidence that early detection can significantly improve health outcomes.

What’s the Current Recommendation to Start Annual Mammograms? It’s 40.

The U.S. Preventive Services Task Force, the American College of Radiology (ACR) and the Society of Breast Imaging all agree on this new guideline.

Here's why:

Breast cancer rates are rising among women in their 40s.
Aligning with this recommendation could save nearly 14,000 lives every year.
Over 85% of women diagnosed with breast cancer have no family history.

Getting a mammogram every year starting at 40 helps detect cancer early—when it’s easiest to treat.

Know Your Risk: Personalized Screening Matters

Women at higher risk for breast cancer are more likely to be diagnosed with more aggressive forms at a younger age. It's important to talk to your doctor to determine whether you may fall into a higher-risk category. Risk factors include:

A family history of breast cancer
A known genetic mutation (such as BRCA, PALB2, or CHEK2)
A personal history of chest radiation or certain breast conditions, such as atypical ductal hyperplasia (ADH) or lobular carcinoma in situ (LCIS)
Black or Ashkenazi Jewish ancestry

At Weill Cornell Imaging at NewYork-Presbyterian, our Genetics and Personalized Cancer Prevention Program (GPCP) offers cancer risk assessments, genetic testing and long-term preventative care, empowering individuals to actively manage their health. The program offers personalized risk assessments and can help you to determine what additional breast imaging is best for you (for example, Breast MRI).

Screening Guidelines

The American Cancer Society recommends the following screening guidelines for early detection of cancer in women who have no symptoms and are not at high risk.

Ages 20-39: Have a clinical breast exam every 3 years as part of your regular health checkup.
Age 40 and older: Schedule a screening mammogram every year and keep on going!

Will the Recommended Starting Age Keep Getting Lower?

Currently, age 40 is the evidence-based recommendation for women at average risk. At this time, there isn’t enough evidence to support routine screening before age 40—unless you are considered high risk.

Stay Informed, Stay Empowered

Breast cancer screening isn’t one-size-fits-all. Understanding your personal and family risk can help you start screening at the right age for you. Staying informed and up to date on screening guidelines is a powerful form of self-care.

One thing is clear: early detection saves lives.

Contributor: Breast Radiologist - Melissa Reichman, MD