Most women should get a mammogram every two years starting at age 40, according to the most recent federal guidelines updated in 2024. That said, some major medical organizations recommend annual screening during certain age ranges, so the “right” answer depends on your age, risk factors, and which guidelines your doctor follows.
The 2024 Federal Recommendation
The U.S. Preventive Services Task Force (USPSTF) updated its breast cancer screening guidelines in 2024, lowering the recommended starting age from 50 to 40. The task force now recommends a screening mammogram every two years for women aged 40 to 74. This applies to women at average risk of breast cancer, meaning no known genetic mutations, no prior breast cancer, and no history of chest radiation at a young age.
The task force specifically looked at annual versus biennial (every two years) screening and concluded that every-other-year mammograms offer a more favorable balance of benefits to harms. The main concern with annual screening is a higher cumulative rate of false positives and unnecessary biopsies over a lifetime of screening.
How Other Organizations Differ
Not every medical group agrees on the same schedule, which is why you may hear conflicting advice. The American Cancer Society takes an age-tiered approach:
- Ages 40 to 44: You can choose to start annual mammograms if you want to, but it’s not a strong recommendation.
- Ages 45 to 54: Annual mammograms are recommended.
- Age 55 and older: You can switch to every two years, or continue annually.
The American College of Obstetricians and Gynecologists (ACOG) takes a more flexible position, recommending mammograms every one to two years based on a shared decision between you and your doctor. In practice, this means your OB-GYN may recommend annual screening if you have additional risk factors or prefer more frequent monitoring, and biennial screening if you’re comfortable with that approach.
The key takeaway is that no major organization recommends screening less often than every two years for women between 40 and 74. The debate is really about whether annual screening adds enough benefit to justify the extra callbacks and anxiety that come with more frequent testing.
What Changes If You’re High Risk
Women at higher-than-average risk for breast cancer typically need more frequent and more thorough screening. This includes women with a known BRCA gene mutation, a strong family history (such as a mother or sister diagnosed before menopause), or a history of radiation therapy to the chest between ages 10 and 30.
For high-risk women, most guidelines recommend annual mammograms plus an annual breast MRI, effectively meaning you get some form of breast imaging every six months (a mammogram at one appointment, an MRI about six months later). The American College of Radiology supports annual breast MRI for high-risk women regardless of breast density. If you’re unsure whether you qualify as high risk, your doctor can calculate a lifetime risk score using tools that factor in family history, genetics, and personal health history.
Why Breast Density Matters
Dense breast tissue makes mammograms harder to read because both dense tissue and tumors appear white on the image. Women with extremely dense breasts have a four- to six-fold greater risk of developing breast cancer compared to women with mostly fatty breast tissue. Dense tissue is also an independent risk factor, meaning it raises your risk on its own, separate from family history or genetics.
If your mammogram report says you have heterogeneously dense or extremely dense breasts (the two densest categories), your doctor may recommend supplemental screening with ultrasound or MRI in addition to your regular mammogram. As of 2024, federal rules require mammography facilities to notify you about your breast density, so you should receive this information with your results. The screening frequency itself doesn’t necessarily change, but the type of imaging may expand.
What to Expect With Callbacks
About 10% of mammograms result in a callback for additional testing. That sounds alarming, but of those callbacks, only about 7% lead to an actual cancer diagnosis. The vast majority turn out to be overlapping tissue, a cyst, or another benign finding. False-positive results are more common during your first mammogram (since there’s no prior image to compare against) and in women with dense breast tissue.
One thing worth knowing: some women avoid returning for their next scheduled mammogram after a false-positive experience. If you’ve been called back before and everything was fine, that’s actually a reason to keep screening on schedule, not to skip it. Your previous images become a baseline that makes future readings more accurate.
3D Versus 2D Mammograms
Many screening centers now offer 3D mammography, also called tomosynthesis, which takes images in thin slices through the breast rather than a single flat picture. 3D mammograms detect more cancers and produce fewer false positives than traditional 2D mammograms, particularly in women with dense breast tissue. The exam feels the same and takes only slightly longer. Whether you get a 2D or 3D mammogram doesn’t change how often you should be screened, but if both options are available, 3D is generally the better choice.
When to Stop Screening
The USPSTF recommendation covers women through age 74. After that, there isn’t strong enough evidence for the task force to make a firm recommendation either way. The American Cancer Society suggests continuing screening as long as you’re in good health and expected to live at least 10 more years. In practical terms, this means a healthy 78-year-old may still benefit from regular mammograms, while someone with serious chronic illness at 72 might reasonably stop. This is a conversation best had with your doctor based on your overall health picture.
Insurance Coverage for Mammograms
Under the Affordable Care Act, most health insurance plans must cover screening mammograms at no cost to you, with no copay, coinsurance, or deductible, as long as you use an in-network provider. This applies to plans purchased through the marketplace and most employer-sponsored plans. Medicare also covers screening mammograms for women 40 and older. If your doctor orders a diagnostic mammogram (because of a symptom or abnormal finding rather than routine screening), cost-sharing rules may differ depending on your plan.