The short answer
BI-RADS is a standardized 0-to-6 scale radiologists use to summarize a mammogram or other breast imaging. Most results fall in the low-concern categories. A higher number, or a category 0, usually means more imaging is needed — not that cancer is confirmed.
BI-RADS is a standard scale radiologists use to summarize breast imaging results.
Categories run from 0 to 6, each with a clear recommended next step.
Most mammograms fall into low-concern categories (1 and 2).
A category 0 means more images are needed, not that something is wrong.
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The full explanation.
The short version
After a mammogram, your report will usually include a BI-RADS category. BI-RADS stands for Breast Imaging Reporting and Data System, and it is simply a standard way for radiologists to summarize what the images show. Each category is a shorthand for a level of concern and a recommended next step.
The categories, in plain terms
BI-RADS runs from 0 to 6:
- 0 — Incomplete. More images or comparison with older ones are needed before a final read. Common, and not a sign that something is wrong.
- 1 — Negative. Nothing notable; routine screening continues.
- 2 — Benign. A finding that is clearly not cancer, like a cyst; routine screening continues.
- 3 — Probably benign. Very likely not cancer, with short-term follow-up imaging (often about six months) to confirm it is stable.
- 4 — Suspicious. A biopsy is usually recommended to find out; many category 4 findings turn out to be benign.
- 5 — Highly suggestive of cancer. A biopsy is strongly recommended.
- 6 — Known cancer. Used when cancer has already been confirmed by biopsy.
Why the scale helps
The value of BI-RADS is that it turns a nuanced image read into a clear, consistent recommendation. Most mammograms fall into categories 1 and 2. A category 0 is a request for more information, not bad news. Higher numbers guide next steps — repeat imaging or a biopsy — rather than serving as a diagnosis on their own.
What a biopsy adds
Only a biopsy can confirm whether a suspicious finding is cancer. That is why categories 4 and 5 point toward one. It is worth remembering that many findings that lead to a biopsy turn out not to be cancer.
What to ask
Ask what BI-RADS category your result is, what the recommended next step is, and when it should happen. Your care team's guidance, based on your images and history, is what applies to you.
Words to know
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Common questions
▸What is a normal BI-RADS score?
Categories 1 and 2 are considered normal or benign findings, with routine follow-up recommended. Most mammograms fall into these categories. Your report will list the category and the recommended next step.
▸What does BI-RADS 0 mean?
Category 0 means the imaging was incomplete and more pictures or a comparison with older images are needed before a final assessment. It is common and does not mean something is wrong — it is a request for more information.
▸Does a higher BI-RADS number mean I have cancer?
Not by itself. Higher categories (like 4 or 5) mean the finding is more suspicious and a biopsy is usually recommended to find out. Only a biopsy can confirm whether cancer is present. Many higher-category findings turn out to be benign.
▸What does BI-RADS 3 mean?
Category 3 means a finding is probably benign, and short-term follow-up imaging (often in about six months) is recommended to confirm it is stable. It signals low concern with a plan to keep an eye on it.
Questions to ask your doctor
Being prepared helps you get the most out of your appointments. Save or print these questions.
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Your next step
Plain-language definitions for the words on your report.
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