Mammogram results: what they mean

What your results letter includes

A radiologist reads the images and, when possible, compares them with your past mammograms. (NCI, 2025) The NCI says you will get the report of a screening mammogram within about 2 weeks, by mail or in your electronic medical record, and the results also go to the provider who ordered it; if you hear nothing within 2 weeks, contact your provider. (NCI, 2025) RadiologyInfo adds: do not assume the results are normal if you do not hear back. (RadiologyInfo, 2025)

Federal rules (the Mammography Quality Standards Act) require facilities to give you an easy-to-read summary of your results. (NCI, 2025) Since September 10, 2024, the summary must also say whether your breast tissue is dense or not dense. When the result is suspicious or highly suggestive of cancer, the summary must reach you within 7 days of the reading; when the result is incomplete because older mammograms are needed, a follow-up report with a final result is due within 30 days. (FDA, 2024)

BI-RADS categories, in plain words

BI-RADS (Breast Imaging Reporting and Data System) sorts results into categories 0 to 6 so doctors describe findings the same way. The same categories can be used for breast ultrasound and MRI, where the next steps may differ slightly. (ACS, 2026) The American Cancer Society and the NCI word the follow-up a little differently, mainly for category 3; the table shows both.

Being called back

Getting called back after a screening mammogram is fairly common and does not mean you have cancer: fewer than 1 in 10 women called back are found to have it. (ACS, 2026) Reasons include:

• the pictures were not clear or did not show all the breast tissue;
• the radiologist sees something to look at more closely, such as calcifications or a mass, which could be a cyst or a solid lump;
• an area looks different from the rest of the breast. (ACS, 2026)

Callbacks are more common after a first mammogram or when there are no older images to compare, before menopause, and with dense breasts. (ACS, 2026) RadiologyInfo says large studies found 3D mammography (tomosynthesis) led to fewer callbacks. (RadiologyInfo, 2025)

What comes next

• Diagnostic mammogram: done like a screening mammogram but with more pictures from more angles, so the radiation dose is higher. A radiologist is usually on hand to make sure all the images needed are taken. (NCI, 2025) (ACS, 2026)
• Breast ultrasound: often added to look at the area of concern. (ACS, 2026)
• Results at the visit: you will most likely hear the same day that the area is nothing to worry about, that it needs another look sooner than usual (often in about 6 months), or that a biopsy is needed. You should also get a letter saying whether more tests are needed and when your next mammogram is due. (ACS, 2026)
• Biopsy: a small piece of tissue is removed and checked under a microscope. Most biopsy results are not cancer, but a biopsy is the only way to know for sure. Most of the time a needle biopsy (fine needle or core needle) can be done; sometimes a surgical biopsy through a cut in the skin is needed. (ACS, 2024)

If you need more tests, ask your doctor when they should be scheduled. (ACS, 2026) More: after an abnormal screening result.

The breast density notice

Your report rates breast density in one of four groups, from almost entirely fatty to extremely dense. (FDA, 2024) Dense tissue makes cancer harder to see on a mammogram and slightly raises the risk of breast cancer. (ACS, 2026) If your tissue is dense, the required notice says other imaging tests in addition to a mammogram may help find cancers in some people, and to talk to your provider about your situation. (FDA, 2024) What the guidelines say about extra imaging is on dense breasts on your mammogram report.

What the follow-up costs

Medicare covers a screening mammogram once every 12 months with nothing to pay if your provider accepts assignment. Diagnostic mammograms are covered when medically necessary, more often than once a year if needed, but you pay 20% of the Medicare-approved amount after the Part B deductible. (Medicare.gov) For other plans, the NCI says to check coverage of a diagnostic mammogram with your insurer. (NCI, 2025)

Questions people ask

Does being called back after a mammogram mean I have cancer?

No. Being called back is fairly common, and the American Cancer Society says fewer than 1 in 10 women called back for more tests are found to have cancer. Often more pictures simply show the area is not cancer. (ACS, 2026)

What does BI-RADS 0 mean?

The result is incomplete. The radiologist needs more imaging, such as extra mammogram views or an ultrasound, or wants to compare with your older mammograms, before giving a final category. (ACS, 2026) (NCI, 2025)

What does BI-RADS 3 mean?

Probably benign, with no more than a 2% chance of cancer. The American Cancer Society says you will likely have repeat imaging in 6 to 12 months and regularly after that, usually for at least 2 years; the NCI table lists a 6-month follow-up mammogram. Your doctor tells you your schedule. (ACS, 2026) (NCI, 2025)

How long do mammogram results take?

The NCI says you will get the report of a screening mammogram within about 2 weeks, by mail or in your electronic record, and to contact your provider if you do not. When the result is suspicious or highly suggestive of cancer, federal rules require the summary to reach you within 7 days of the reading. (NCI, 2025) (FDA, 2024)

Does Medicare cover the follow-up mammogram?

Medicare covers diagnostic mammograms when medically necessary. Unlike screening mammograms, you pay 20% of the Medicare-approved amount after the Part B deductible. For other plans, check with your insurer. (Medicare.gov) (NCI, 2025)

Related

• Breast cancer screening
• Mammogram: what to expect, how to prepare, 3D vs 2D
• Dense breasts on your mammogram report
• BRCA test results: positive, negative and VUS explained
• After an abnormal screening result
• False positives and overdiagnosis