For most women at average risk, the recommended schedule is a mammogram every two years starting at age 40 and continuing through age 74. That’s the current guidance from the U.S. Preventive Services Task Force, updated in 2024. But the answer gets more nuanced depending on your age, risk level, and breast density.
The Standard Schedule for Average-Risk Women
The USPSTF recommends biennial (every two years) screening mammography for all women aged 40 to 74. This applies to cisgender women and all people assigned female at birth, including transgender men and nonbinary individuals. The recommendation carries a B grade, meaning there’s high confidence that the net benefit is moderate.
Not every major organization agrees on the exact interval. The American College of Obstetricians and Gynecologists recommends screening every one or two years, leaving the specific timing to a shared decision between you and your doctor. Some women and their providers choose annual screening, especially during the years when breast cancer risk is climbing. Others stick with every two years and feel comfortable with that tradeoff.
Why Every Two Years Instead of Every Year
The main reason guidelines favor biennial over annual screening comes down to false positives. Over a 10-year period starting at age 40, women who screen annually have a 61% cumulative chance of getting at least one false-positive mammogram result, compared to 42% for women who screen every two years. The rate of unnecessary biopsies is also higher: 7% for annual screening versus 5% for biennial.
A false positive means you get called back for additional imaging or a biopsy that ultimately shows no cancer. While it’s reassuring to get the all-clear, the process causes real anxiety, takes time, and costs money. Biennial screening catches most of the same cancers that annual screening would, with significantly fewer of these false alarms. For average-risk women, the evidence suggests that every-two-year screening strikes the best balance between catching cancer early and avoiding unnecessary procedures.
When You Need Screening More Often
If you’re at high risk for breast cancer, the schedule changes substantially. The American Cancer Society recommends that high-risk women get both a mammogram and a breast MRI every year, typically starting at age 30. MRI catches cancers that mammograms miss, but it also works the other way around, so both tests are used together rather than one replacing the other.
You’re generally considered high risk if you:
- Have a lifetime breast cancer risk of 20% or higher based on family history
- Carry a BRCA1 or BRCA2 gene mutation, or have a first-degree relative with one
- Had radiation therapy to the chest before age 30
- Have certain genetic syndromes like Li-Fraumeni or Cowden syndrome
The National Comprehensive Cancer Network adds another layer of specificity. For women with a strong family history, annual mammograms should begin 10 years before the age their youngest affected family member was diagnosed, but not before age 30, or at age 40, whichever comes first. These women should also get annual breast MRI and clinical exams every 6 to 12 months. If your family history suggests a genetic predisposition, a referral to a genetic counselor can help clarify your actual risk level and the right screening plan.
How Breast Density Affects Screening
Dense breast tissue makes mammograms harder to read because both dense tissue and tumors appear white on the image. If you’ve been told you have dense breasts (roughly half of women under 50 do), your doctor may recommend additional screening beyond standard mammography.
Digital breast tomosynthesis, sometimes called 3D mammography, improves cancer detection in women with moderately dense breasts but may be less effective for those with extremely dense tissue. Ultrasound is the most commonly used supplemental tool and does improve detection of early-stage invasive cancers, though it also increases the chance of false positives. For high-risk women of any breast density, the Society of Breast Imaging recommends annual contrast-enhanced MRI as supplemental screening.
Your breast density alone doesn’t necessarily change how often you get mammograms, but it may mean additional imaging tests are layered on top of your regular schedule. Many states now require that mammogram results include a notification about your breast density so you can discuss next steps with your provider.
When Screening Typically Ends
Most guidelines set 74 or 75 as the upper age for routine screening, but the cutoff isn’t really about a birthday. The more relevant factor is life expectancy. Several guidelines recommend continuing screening only for women with at least 10 more years of expected life, since breast cancer detected by screening tends to be slow-growing, and the benefit of early detection diminishes when competing health conditions are more likely to affect outcomes first.
Research published in the Journal of the American Geriatrics Society found that few older women are aware of these stopping guidelines. If you’re over 74 and in good health, screening may still make sense. If you have significant other health conditions, the potential harms of false positives and overdiagnosis may outweigh the benefits. This is a conversation worth having with your doctor rather than following a one-size-fits-all age cutoff.