The Who, What, Where, When and Sometimes, Why.


What is a mammogram?

Mammography is a test that uses X-rays to create images of the breast. These images are called mammograms.

A radiologist trained to read mammograms studies the images and looks for signs of breast cancer.

Mammogram images are stored on a computer. This is called digital mammography.

Since digital images are viewed on a computer, they can be lightened or darkened, and certain sections can be enlarged and looked at more closely.

Digital breast tomosynthesis (3D mammography)

Today, most women have mammography with digital breast tomosynthesis (DBT). DBT is also called “tomo” or 3-dimensional (3D) mammography. It takes multiple 2-dimensional (2D) digital images of the breast, and computer software combines the 2D images to create a 3D image.

Radiologists must have special training to read these DBT images.

Studies show DBT may find a few more breast cancers than 2D digital mammography [2-7]. DBT may also reduce recall rates (when women are called back for more imaging or other testing after a screening mammogram) [4-6,9].

DBT may give a slightly higher radiation dose than standard 2D mammography [8-10]. This higher dose is within FDA guidelines though [8,10].

Whether you get DBT or 2D digital mammography, you’re getting standard of care.


For a summary of research studies on DBT for breast cancer screening, visit the Breast Cancer Research Studies section.

How is mammography used?

Screening tests

Breast cancer screening tests are used to find breast cancer in people who have no warning signs or symptoms.

Overall, mammography is the most effective screening test used today to find breast cancer in most women. It can find cancers at an early stage, when the chances of long-term survival are highest.

Learn about mammography recommendations for women at average risk of breast cancer.

Learn about mammography recommendations for women at higher risk of breast cancer.

Learn about mammography recommendations for transgender people.

Follow-up mammograms (diagnostic mammograms)

Mammography can be used as a follow-up test when something abnormal is found on a screening mammogram, during a clinical breast exam or when a person notices a change in their breast.

A mammogram used as a follow-up test is called a “diagnostic mammogram.” Although it’s called a “diagnostic mammogram,” it can’t diagnose breast cancer. It can show whether the abnormal findings look like they could be breast cancer. Other follow-up tests may be recommended.

If the findings look like they could be breast cancer, you’ll need a biopsy to diagnose or rule out breast cancer.

Whether you’re getting a screening mammogram or a diagnostic mammogram, the basic procedure is the same. However, with a diagnostic mammogram, more views will likely be taken. 

Getting a mammogram

If you’re getting a mammogram for the first time, you may have questions about what to expect before and after.

Learn about getting a mammogram, including information for women who have breast implants and women who have a physical disability.

What does a mammogram show?

Like other X-ray images, mammograms appear in shades of black, gray and white, depending on the density of the breast tissue. Dense breast tissue looks different from fatty breast tissue on a mammogram.

Learn more about breast density on a mammogram.

Findings on a mammogram

A mammogram may show:

Learn more about findings on a mammogram and when to expect your mammography results.

Follow-up after an abnormal mammogram

If your screening mammogram shows something abnormal, you’ll need follow-up tests to check whether or not the finding is breast cancer.

Learn about follow-up after an abnormal mammogram.

Accuracy of mammography

Although mammography is the most effective screening test used today to find breast cancer in most women, it’s not perfect.

Learn about the accuracy of mammograms.


For a summary of research studies on mammography in women ages 40-49, visit the Breast Cancer Research Studies section.

 52805-2.gifFor a summary of research studies on mammography in women ages 50-69, visit the Breast Cancer Research Studies section.

For a summary of research studies on digital breast tomosynthesis (3D mammography) for breast cancer screening, visit the Breast Cancer Research Studies section.

Weighing the benefits and risks of screening mammography

Most major health organizations agree screening mammography lowers a woman’s risk of dying from breast cancer [8-9,11].

However, there’s ongoing debate about how much benefit women get from screening mammography (especially younger women) and whether this benefit outweighs the risks.

There’s also debate about when to begin screening mammography and how often to have it.

Learn more about the benefits and risks of screening mammography.

Women Should Have Access to and Coverage for Mammography

Susan G. Komen® believes all women should have access to regular screening mammograms when they and their health care providers decide it’s best based on their risk of breast cancer.

Komen also believes screening should be covered by insurance companies, government programs and other third-party payers, with no out-of-pocket costs for patients.

Radiation exposure during a mammogram

You’re exposed to a small amount of radiation during a mammogram. While this radiation exposure might increase the risk of breast cancer over time, this increase in risk is very small [12-15].

Studies show the benefits of mammography outweigh the small risks from radiation exposure, especially for women ages 50 and older [12-13,16].

Contrast-enhanced digital mammography (CEDM) is a breast imaging technique. Compared to standard mammography, CEDM makes a stronger contrast between a breast tumor and the surrounding tissue. The image is somewhat similar to a breast MRI image.

CEDM is a fairly new technique and its benefits are not yet well understood.

CEDM and breast cancer screening for women at higher risk

CEDM is a breast cancer screening option for some women at higher risk of breast cancer [9]. This includes women at higher risk of breast cancer for whom breast MRI is recommended, but who cannot have breast MRI for medical reasons [9].

Possible risks of CEDM

A contrast agent is given by vein (through an IV) before the procedure. In rare cases, people can have an allergic reaction to the contrast agent.

More X-ray images of the breast are taken than with a standard mammogram, so there’s slightly more radiation exposure.

CEDM is not widely available, so it’s not routinely used.

Under study

CEDM is under study for use as a follow-up test after an abnormal finding on a mammogram [17-18].

Low-cost or free mammograms

Medicare, Medicaid and most insurance companies cover the cost of screening mammograms.

Since September 2010, the Affordable Care Act has required all new health insurance plans to cover screening mammograms [19]. Health plans must cover screening mammography, with no co-payment, every 2 years for women 50 and older, and as recommended by a health care provider for women 40-49 [19].

If you don’t have insurance or your insurance doesn’t cover screening mammograms, the resources below may help you find a free or low-cost mammogram.

Susan G. Komen®’s Breast Care Helpline:
1-877 GO KOMEN (1-877-465-6636)

Looking for a no or low-cost screening? Contact the Breast Care Helpline. Our team of trained specialists and oncology social workers can help.

The Helpline provides free, professional support services and resource referrals to anyone who has questions or concerns about breast health, including people diagnosed with breast cancer and their families Monday through Friday from 9:00 a.m. to 10:00 p.m. ET. You can also email the Helpline at Se habla español.

Residents of these areas may be eligible for Susan G. Komen’s Screening & Diagnostics Program:

  • Atlanta
  • Chicago
  • Dallas-Fort Worth
  • Houston
  • Los Angeles and Orange County
  • Memphis
  • Philadelphia
  • Virginia Beach
  • Washington, D.C.
  • Central Wisconsin

Working in partnership with local health systems in select cities, Komen provides no-cost breast cancer screening and diagnostic services for those who meet income guidelines. The program is open to all ages and genders.

To learn more or to complete an application, contact the Komen Breast Care Helpline at 1-877-465-6636 or If you do not meet the program’s eligibility criteria, Helpline specialists can help you identify other potential resources.

For more on this program, listen to our Real Pink podcast, Chances of Early Detection Improve With Screening & Diagnostics Program.

The National Breast and Cervical Cancer Early Detection Program provides access to breast cancer screening to low-income, uninsured and underinsured women ages 40-64. It also provides access to diagnostic testing if screening results are abnormal, and it provides referrals to treatment if breast cancer is diagnosed.

Each October, during National Breast Cancer Awareness Month, many imaging centers offer mammograms at reduced rates. To find a certified mammography center in your area, visit the FDA website (

Updated 11/30/22