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.

Digital mammography

In the past, mammogram images were stored on film (film mammography). Now, mammogram images are almost always stored on a computer (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.

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 survival are highest.

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

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

Follow-up tests

Mammography can be used as a follow-up test when something abnormal is found on a screening mammogram or a clinical breast exam.

A mammogram used as a follow-up test (instead of screening) 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 breast cancer though.

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 3D mammography for breast cancer screening, visit the Breast Cancer Research Studies section.

Weighing the risks and benefits of screening mammography

Most major health organizations agree mammography lowers a woman’s risk of dying from breast cancer [2-4].

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 is best based on their personal risk of breast cancer. In addition, screening should be covered by insurance companies, government programs and other third-party payers.

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 [5-8].

Studies show the benefits of mammography outweigh the small risks from radiation exposure, especially for women ages 50 and older [5-6,9].

What is digital breast tomosynthesis (DBT)?

Digital breast tomosynthesis (DBT), also called “tomo” or three-dimensional (3D) mammography, takes multiple 2-dimensional (2D) digital images of the breast. Computer software combines the 2D images to create a 3D image.

Radiologists must have special training to read these DBT images.

Getting a DBT mammogram

Getting a DBT mammogram is similar to getting a 2D mammogram.

A DBT mammography machine provides both a 2D mammogram and an enhanced 3D image based on multiple 2D images. All the images are taken on the same machine, so you stay in one place while all the images are taken.

A DBT mammogram takes a few seconds longer than a 2D mammogram because more images are taken. If you’ve had a 2D mammogram in the past, you may not notice a difference.

DBT may give a slightly higher radiation dose than standard 2D mammography [3,10-12]. This higher dose is within FDA guidelines [3,10-11].

Breast cancer screening with DBT

Studies show DBT may find a few more breast cancers than 2D mammography [3,9-10,13-18]. Whether DBT is better than standard 2D mammography for breast cancer screening is still under study [3].

The American Cancer Society and the National Comprehensive Cancer Network breast cancer screening guidelines state either 2D mammography or DBT may be used for screening [3-4].

Many centers offer DBT. Although most insurance plans cover the cost, it’s best to check with your insurance company and the imaging center before getting a DBT mammogram.

Learn more about screening recommendations for women at average risk


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

Low-cost or free mammograms

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

Since September 2010, the Affordable Care Act has required all new health insurance plans to cover screening mammograms, with no co-payment [19]. Health plans must cover mammography 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 mammograms, the resources below may help you find a low-cost or free mammogram.

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

Calls to the Komen Breast Care Helpline are answered by a trained and caring staff member Monday through Friday from 9:00 a.m. to 10:00 p.m. ET. The helpline provides free, professional support services to anyone who has questions or concerns about breast cancer, including people diagnosed with breast cancer and their families.

You can also email the helpline at

Se habla español.

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 results are abnormal, and 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 11/10/21