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Screening & findings
The four screening guidelines, side by side
Four serious organizations look at broadly the same evidence and land in different places on when to start mammograms and how often to have them. This page lays out what each one actually says, so you can see the disagreement rather than be caught in the middle of it.
Four guidelines, four starting ages
All four of the organizations below are serious, respected, and looking at broadly the same evidence. They still land in different places. Every recommendation here is for women at average risk, meaning no personal history of breast cancer, no high-risk breast lesion, no known gene change such as , and no high-dose radiation to the chest at a young age.
| Who | In your 40s | 50 to 74 | 75 and older |
|---|---|---|---|
| American Cancer Society | Option to start every year at 40. Every year from 45. | Every year to 54. From 55, every year or every other year, your choice. | Keep going while you are in good health and expected to live at least 10 more years. |
| US Preventive Services Task Force | Every other year from 40. | Every other year. | Not enough evidence either way. A judgment call with your doctor. |
| American College of Radiology and Society of Breast Imaging | Every year from 40. A risk assessment for everyone by age 25. | Every year. | Continue based on health, not on age alone. |
| American College of Physicians (April 2026) | Talk it through first. If you decide to screen, every other year. | Every other year. | Discuss stopping, and also if life expectancy is limited. |
The gap between the most and least intensive advice, for a woman at average risk in her forties, is roughly one mammogram a year versus one every two years, or a conversation instead of a booking. That is a real difference, and it is a reasonable thing to have an opinion about.
Why the screening guidelines disagree
Screening catches cancers early, when they are smaller and easier to treat. That is the benefit and it is not in dispute. The disagreement is about how to weigh it against three costs.
- False alarms. Being called back for more pictures when everything turns out to be fine. It happens often, particularly on a first mammogram, and the fortnight of worry in between is a genuine harm.
- Overdiagnosis. Finding a cancer that would never have caused trouble in that person’s lifetime, and treating it anyway. Nobody can tell at the time which ones those are.
- Cost, radiation, and access. Small individually, real across a whole population.
Groups that weight the lives saved most heavily land on annual screening from 40. Groups that weight false alarms and overdiagnosis more heavily land on every other year, or on a conversation in your forties. Both are defensible readings of the same data.
This is not a quiet academic difference. When the American College of Physicians published its April 2026 guidance, the American College of Radiology and the Society of Breast Imaging issued a public statement the same day arguing that the advice relies on outdated information and would cost lives. It is worth knowing that the professional bodies are openly at odds, because it explains why your primary care doctor and a breast specialist may tell you different things and both be quoting a guideline.
If you notice a change in your breast, screening guidelines stop applying to you. Guidelines are for people with no symptoms. A new lump, a change in the skin or nipple, or discharge from one side needs a and an appointment, whatever your age and whenever your last mammogram was.
What Dr. Perkins recommends for screening
“I recommend following the American College of Radiology and Society of Breast Imaging, with mammograms every year from age 40 and risk assessment by age 25. This is safe and conservative, and it establishes a good routine for taking care of yourself.”
Those are two of the four sets of advice compared above. Choosing them means starting a year earlier than some groups advise and going every year rather than every other year, and it means having your own risk worked out in your twenties rather than waiting until screening is due. If your own doctor follows a different guideline, the table above shows what each one says and why they differ.
Where this comes from
- American Cancer Society recommendations for the early detection of breast cancer
- US Preventive Services Task Force, Breast Cancer: Screening, Grade B for women aged 40 to 74
- Breast Cancer Screening for Women at Higher-Than-Average Risk: Updated Recommendations From the ACR, Journal of the American College of Radiology, 2023
- ACR and Society of Breast Imaging statement, 17 April 2026
- Screening for Breast Cancer in Asymptomatic, Average-Risk Adult Females: A Guidance Statement From the American College of Physicians (Version 2), Annals of Internal Medicine, 17 April 2026
- NCCN Guidelines for Breast Cancer Screening and Diagnosis
- US Food and Drug Administration, Mammography Quality Standards Act final rule, breast density notification required from 10 September 2024
Guidelines change. This page states what each organization said on the date above. If you are reading it long after that, check the links.