Quick Answer: BI-RADS is a standard score from 0 to 6 that radiologists use to summarise a mammogram or ultrasound. A low number (1 or 2) means normal or benign; 3 means probably benign with short-interval follow-up; 4 and 5 mean a biopsy is advised; 0 means more imaging is needed. Your score tells you the next step, not a diagnosis.
A breast imaging report can read like code, and the BI-RADS number is often the part that causes the most worry. It is simply a shorthand radiologists use to say how likely a finding is to be benign or concerning, and what should happen next. Understanding it turns an intimidating report into a clear plan.
This guide from Melanie Seah Breast Specialist explains each BI-RADS category and what it means for you in 2026. You will learn what the numbers 0 to 6 mean and how a breast surgeon in Singapore uses your score to decide the next step.
What does my BI-RADS score mean?
Your BI-RADS score is a number from 0 to 6 that sums up how suspicious your mammogram or ultrasound finding is. Categories 1 and 2 are normal or benign, category 3 is probably benign, and categories 4 and 5 mean a biopsy is recommended. Category 0 means the images are incomplete and more imaging is needed.
The system was created by the American College of Radiology to standardise reports so every doctor reads them the same way. Category 3 carries a risk of cancer below 2%, while category 5 carries a 95% or greater likelihood of cancer (American College of Radiology). Your mammogram screening report will state one of these.
At Melanie Seah Breast Specialist in Singapore, Dr Melanie Seah translates your BI-RADS score into a plain-language plan, whether that is routine screening, a short-interval scan, or a breast core biopsy.
THE BI-RADS SCALE AT A GLANCE
| BI-RADS | Meaning | Usual next step |
|---|---|---|
| 0 | Incomplete — needs more imaging | Extra views or ultrasound |
| 1 | Negative (normal) | Routine screening |
| 2 | Benign finding | Routine screening |
| 3 | Probably benign (<2% risk) | Short-interval follow-up scan |
| 4 | Suspicious | Biopsy advised |
| 5 | Highly suggestive of cancer (≥95%) | Biopsy advised |
| 6 | Known, biopsy-proven cancer | Treatment planning |
What is the difference between BI-RADS 3 and BI-RADS 4?
BI-RADS 3 means a finding is probably benign, with a cancer risk below 2%, so it is usually watched with a follow-up scan rather than biopsied straight away. BI-RADS 4 means a finding is suspicious enough that a biopsy is recommended to be sure. The jump from 3 to 4 is the point where testing is advised.
Category 4 is often split into 4A, 4B and 4C to show low, moderate or high suspicion (roughly 2–10%, 10–50% and 50–95% risk). This helps you understand how concerned the radiologist is, though all three lead to a biopsy (American College of Radiology).
A BI-RADS 3 result is not a cause for alarm, but the follow-up scan matters because it confirms stability. Dr Melanie Seah explains why watching is safe for a category 3 finding at her Singapore clinic, so you are not left uncertain between scans.
Do I always need a biopsy for BI-RADS 4 or 5?
“A BI-RADS 4 is not a diagnosis of cancer — it is a recommendation to check. Many category 4 biopsies come back benign, and that certainty is exactly why we do them.” — Dr Melanie Seah, consultant breast surgeon, Melanie Seah Breast Specialist
A biopsy is recommended for BI-RADS 4 and 5 findings, but a category 4 result does not mean you have cancer. Because the risk in category 4 ranges from about 2% to 95%, many category 4 biopsies turn out benign. The biopsy provides the certainty needed to decide what, if anything, comes next.
A BI-RADS 5 finding is highly likely to be cancer and is confirmed by biopsy before treatment is planned. Because breast cancer is the most common cancer among women in Singapore, prompt, accurate assessment matters (National Cancer Centre Singapore). Dr Melanie Seah performs ultrasound-guided biopsy at her Singapore clinic and explains the result clearly.
What should I do after receiving my BI-RADS result?
What to do depends on the number: categories 1 and 2 mean continue routine screening, category 3 means return for a short-interval scan, and categories 4 and 5 mean arrange a biopsy. Category 0 means you need additional imaging before a final score can be given.
Whatever the number, the most useful step is to discuss it with a breast specialist who can put it in the context of your history and risk. A score on paper becomes far less frightening once it is explained alongside a plan.
At Melanie Seah Breast Specialist in Singapore, Dr Melanie Seah reviews your images and BI-RADS category with you and arranges the appropriate next step in one place. You can book a consultation to go through your report.
Frequently Asked Questions
Your BI-RADS score is a 0–6 summary of how suspicious a finding is and what to do next. Categories 1 and 2 are normal or benign, 3 is probably benign with a follow-up scan, and 4 and 5 mean a biopsy is advised; 0 means more imaging is needed (American College of Radiology). It is a next-step guide, not a diagnosis. At Melanie Seah Breast Specialist in Singapore, Dr Melanie Seah explains your specific category and arranges the right follow-up, so the number on your report translates into a clear plan.
A BI-RADS 3 result is “probably benign” and carries a cancer risk below 2%, so it is usually watched with a short-interval scan rather than biopsied immediately (American College of Radiology). The follow-up confirms the finding is stable. It is not a cause for alarm, but attending the follow-up scan matters. In Singapore, Dr Melanie Seah explains why watchful follow-up is safe for a category 3 finding and ensures you have a clear date and plan for the next scan, so you are not left uncertain in between.
No — BI-RADS 4 means suspicious enough to biopsy, not confirmed cancer. Category 4 covers a wide risk range (about 2–95%), and many category 4 biopsies come back benign (American College of Radiology). The biopsy is done to gain certainty. Because breast cancer is the most common cancer in Singapore women, checking a suspicious finding promptly is sensible (National Cancer Centre Singapore). At her Singapore clinic, Dr Melanie Seah performs the biopsy and explains the result, so a category 4 score leads quickly to an answer rather than prolonged worry.
BI-RADS 4 is suspicious and 5 is highly suggestive of cancer, with a likelihood of 95% or more (American College of Radiology). Both lead to a biopsy, but a category 5 finding is confirmed before treatment planning begins, whereas many category 4 findings turn out benign. The distinction reflects how concerned the radiologist is. In Singapore, Dr Melanie Seah uses your category to prioritise the biopsy and plan next steps, and she explains what each number means for your particular result.
A BI-RADS score is a roadmap, not a verdict — it tells you and your doctor what should happen next. Low numbers mean routine care, a 3 means a watchful follow-up, and a 4 or 5 means a biopsy for certainty. If your report has left you uncertain, arrange a review with Dr Melanie Seah at Melanie Seah Breast Specialist in Singapore. Get in touch to book a consultation and go through your result.
