Mammograms can detect breast cancer early before symptoms appear, and regular screening decreases the risk of dying from breast cancer. But a recent survey conducted by the Annenberg Public Policy Center (APPC) of the University of Pennsylvania shows that some Americans appear to be confused about when women with an average risk of breast cancer should begin a regimen of regular mammograms.
History of Screening Recommendations
Women with an average risk of breast cancer should begin to have mammograms every other year beginning at age 40 years, according to the U.S. Preventive Services Task Force (USPSTF), which issued an updated recommendation published in JAMA in April 2024, formalizing an earlier draft proposal. The recommendation applies to women from ages 40 to 74 years.
Guidance from major medical organizations on what age to begin regular mammograms has changed over the years—from 40 years, to 50, and then back to 40 again. While a start date of age 40 is widely recommended, some medical organizations have put forth other recommendations. The American Cancer Society, for instance, advises that women with average risk have the option to start screening every year from age 40 to 44, then should have mammograms annually from 45 to 54 years old, and then continue with mammograms every other year.
Recent Survey Findings
The APPC’s health survey, conducted with a sample of over 1,600 U.S. adults in April, found that nearly half of those surveyed (49%) knew that age 40 is when women at an average risk of breast cancer should begin to have mammograms every other year. But 10% replied they should begin at age 20; 21% said age 30; 8% said age 50; and 11% were not sure.
“Confusion can arise when medical guidance about detection or treatment changes, as it has in recent years with mammograms,” said Kathleen Hall Jamieson, Director of the APPC. “Our data suggest that the recommendation that such screening ordinarily start at 40 years old is not yet widely enough known.”
Interestingly, in APPC's April 2024 survey, conducted before the USPSTF lowered its recommendation from age 50 to age 40, the overall finding was the same: 49% of survey respondents thought the correct age to begin mammographic screening was 40. However, that was not the recommended age at that time, though it is today with the updated medical advice.
More Uncertainty Among Younger Women
Among the women surveyed, nearly three-quarters (72%) who were aged 40 to 49 years old knew that regular mammograms should begin at age 40. About 6 in 10 women aged 30 to 39 (63%) and 50 to 74 (59%) knew this as well. Younger women were the least well-informed about when to begin mammograms—among women 18 to 29, just over one-third (37%) knew the correct age.
In addition, more younger women said they were not sure what the correct age is. The survey found that 16% of women aged 18 to 29 and 11% of women aged 30 to 39 reported not being sure at what age to begin having mammograms. There is no statistically significant difference between those two age groups—but both differ significantly from the very small percentage of women 40 to 49 years old—only 1%—who were not sure of the age to being having mammograms.
Among 18- to 29-year-old women, the most commonly selected incorrect age for when to begin regular mammography was 30 years old (selected by 27%). Among women aged 30 to 39—those who are approaching the recommended start age for mammograms—the most commonly selected incorrect age was 50 years old (selected by 12%).
More on the Survey
The survey data come from the 24th wave of a nationally representative panel of 1,653 U.S. adults conducted for the APPC by SSRS, an independent market research company. Most have been empaneled since April 2021. To account for attrition, replenishment samples have been added over time using a random probability sampling design. The most recent replenishment, in September 2024, added 360 respondents to the sample. This wave of the Annenberg Science and Public Health survey was fielded April 15–28, 2025. The margin of sampling error is ± 3.4 percentage points at the 95% confidence level. All figures are rounded to the nearest whole number and may not add to 100%. Combined subcategories may not add to totals in the topline and text due to rounding.
