Routine mammograms are recommended starting at age 40 for women at average risk of breast cancer. This represents a significant shift: until recently, several major medical organizations suggested waiting until 45 or 50. Now, virtually every leading U.S. health authority agrees on 40 as the right starting point.
The Current Recommendation: Start at 40
The U.S. Preventive Services Task Force updated its guidelines to recommend screening mammograms every two years for women aged 40 to 74. This brought the USPSTF in line with the American College of Radiology, the National Comprehensive Cancer Network, the Society of Breast Imaging, and the American College of Obstetricians and Gynecologists, all of which had already endorsed starting at 40. ACOG specifically noted that the benefits of catching breast cancer earlier outweigh the risks of occasional false alarms or unnecessary follow-up.
The American Cancer Society takes a slightly different approach to timing. It says women between 40 and 44 have the option to start yearly screening, women 45 to 54 should get mammograms every year, and women 55 and older can switch to every other year if they choose. The key difference across organizations is really about frequency (every year vs. every two years), not whether to start at 40.
How Often You Need One
The USPSTF recommends every two years (biennial screening). The American College of Radiology recommends every year, regardless of breast density or personal risk level. The American Cancer Society recommends annual screening from 45 to 54, then gives the option to go to every other year after 55.
If you’re wondering which schedule to follow, a few factors can help you decide. Annual screening catches more cancers early but also means more callbacks for additional imaging that turns out to be nothing. Biennial screening reduces those false alarms while still providing meaningful protection. Your personal risk factors, including family history, breast density, and overall health, can tip the balance one way or the other.
When to Start Earlier Than 40
Some women need screening well before their 40th birthday. The American College of Radiology recommends that women with certain genetic mutations, a calculated lifetime breast cancer risk of 20% or higher, or a history of chest radiation at a young age begin MRI screening between ages 25 and 30, with mammograms starting sometime between 25 and 40 depending on the specific risk factor. Women who carry genetic mutations linked to breast cancer can delay mammograms until 40 as long as they’re getting annual breast MRI in the meantime.
Because these high-risk factors need to be identified early, the ACR recommends all women undergo a risk assessment by age 25. This is especially important for Black women and women of Ashkenazi Jewish heritage, who face higher rates of certain genetic risk factors. A risk assessment is typically a conversation with your doctor that includes questions about family history, and sometimes a formal calculation tool that estimates your lifetime risk.
When to Stop Screening
The upper age limit is less clear-cut than the starting age. The USPSTF’s recommendation covers women through age 74 and states there isn’t enough evidence to say whether mammograms help or hurt after 75. No major screening trials have included women 75 or older, and one study that tried to simulate trial conditions found no benefit for women screened between ages 75 and 84.
The American Cancer Society takes a different approach, recommending that screening continue as long as a woman is in good health and expected to live at least 10 more years. This means a healthy 78-year-old might reasonably continue screening, while a 70-year-old with serious health problems might not benefit from it. After 74, the decision becomes more individual.
Insurance Coverage for Mammograms
Under the Affordable Care Act, all Marketplace health plans and many other insurance plans must cover screening mammograms every one to two years for women 40 and older with no copay or coinsurance. This means cost shouldn’t be a barrier once you reach the recommended starting age. If you’re under 40 and need early screening due to high risk, coverage varies by plan, so it’s worth checking with your insurer.
3D vs. Traditional Mammography
When you schedule a mammogram, you may be offered a choice between a standard 2D mammogram and 3D mammography (also called tomosynthesis). A 3D mammogram takes multiple images of the breast from different angles, creating a layered picture that can make it easier to spot abnormalities, particularly in dense breast tissue. Both are considered appropriate for routine screening starting at 40. Many imaging centers now use 3D mammography as their default, though availability varies by location.
Screening for Men
Male breast cancer is rare, but men with known genetic risk factors can develop it. Current guidelines recommend that high-risk men begin breast self-examination and clinical breast exams at age 35. Annual mammography is an option for men who have enlarged breast tissue (gynecomastia), though screening recommendations for men are less standardized than for women. Men with a strong family history of breast cancer or known genetic mutations should discuss their individual risk with a doctor.