How often should an average-risk woman have a mammogram?

For women at average risk, the US Preventive Services Task Force recommends a mammogram every two years, from age 40 through age 74.

The Task Force calls this biennial. That word just means every other year. They gave it a grade B, which is their rating for moderate net benefit.

Guidance in this area has shifted. That is a big reason why friends the same age have heard different things.

The 2024 recommendation replaced guidance from 2016. The older version treated screening in your forties as a personal choice, made with a doctor. The current version says all women should start screening at age 40.

If someone told you a decade ago that starting at 40 was optional, that was true at the time. It has since changed.

Past age 74, the Task Force did not make a call either way. It found that current evidence is not enough to weigh the benefits and harms of screening mammograms in women 75 and older. This is called an I statement.

It is easy to misread that as "screening stops at 75." It does not say that. It says the right studies have not been done yet to answer the question well.

Where evidence runs out, a personal talk with your doctor replaces a general rule.

For an older woman, that talk usually covers overall health, other conditions, and what she would want if something were found. Those are personal factors no general guideline can settle for you.

This guidance is written for women at average risk. A few things move a person outside that group. These include a strong family history of breast or ovarian cancer, a known inherited gene change, or past radiation treatment to the chest.

If any of those fit you, your right schedule may start earlier or happen more often. Set it with your doctor, not by reading a general guideline alone.

Screening has benefits, and it has costs. The Task Force weighs both.

The benefit is finding cancers earlier, when treatment tends to work better. The costs include extra imaging or a biopsy that turns out not to be cancer, plus the worry that comes with that. Screening more often raises both sides of that scale.

Two years is the Task Force's best judgment for where those two things balance for average-risk women in this age range. Other expert groups reach slightly different conclusions. That is one more reason a personal talk is worth having, rather than assuming any single schedule is the only right one.

Guidelines only help if you actually book the appointment. Two small habits make a real difference. Put your next mammogram on the calendar the same day you go for this one. And keep track of where your past images were taken — comparing new scans to old ones truly helps a radiologist.

Patients often find that a medical group, a hospital website, and a friend's clinic all quote slightly different schedules. That is not carelessness. Different expert groups look at the same evidence and land on somewhat different judgment calls.

The Task Force's job is to review the evidence and rate the net benefit for one defined group of people. Their rating system is worth knowing. A grade B means they judged a moderate net benefit. An I statement means the evidence was not enough to judge at all.

If your doctor gives advice that differs from what you have read, ask why instead of assuming someone is wrong. Often the reason is specific to you — a family history, a past biopsy, dense tissue on an old scan. Hearing that reason helps more than any general schedule.

Write down the plan you and your doctor agree on. Guidelines change over time. Your own written plan is what you will actually follow.