Mammography

What is a mammogram?

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

Today, most mammography is done 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.

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

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

When you schedule your mammography appointment, check that DBT is covered by your insurance.

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 men with a BRCA1, BRCA2 or PALB2 inherited gene mutation.

Learn about mammography recommendations for transgender people.

Follow-up mammograms (diagnostic mammograms)

Mammography can also 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. However, it can show whether the abnormal findings look like breast cancer. Sometimes, more follow-up tests are recommended.

If the findings look like they could be breast cancer, you may need a breast ultrasound to get a better image. If there’s still concern, 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.

Findings on a mammogram

A mammogram may show:

• No signs of breast cancer
• A benign (not cancer) breast condition or other change that does not suggest cancer
• An abnormal finding that needs follow-up tests to rule out cancer

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

Breast density

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.

The following is an interactive model of what a mammogram may show.

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 an effective breast cancer screening test, 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.
	For 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 [2-4].

However, there’s ongoing debate about how much benefit women get from screening mammography (especially women younger than 50) and whether this benefit outweighs the risks [28].

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.

Affordable Access to Breast Imaging

Susan G. Komen® believes all people should have access to regular screening when they and their health care providers decide it’s best based on their personal risk of breast cancer. Komen’s Center for Public Policy is working with state and federal lawmakers to ensure needed screening and diagnostic imaging are covered by health plans, 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 [5-8].

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

Contrast-enhanced digital mammography (CEM)

CEM is a fairly new breast imaging technique, and its benefits are not yet well understood. It’s not a standard tool for breast cancer screening.

However, some women at higher risk of breast cancer who are recommended breast MRI as part of breast cancer screening, but who cannot have breast MRI for medical reasons, may consider CEM [3].

CEM is not widely available.

Learn more about CEM.

Low-cost or free mammograms

Medicare, Medicaid and private 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 with no co-payment [11]. Health plans must cover screening mammography at least every 2 years for women 40 and older, and every year if recommended by a health care provider [11].

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

Susan G. Komen® Patient Care Center

Do you need more information about breast cancer screening or low-cost programs in your area? We’re here for you. The Komen Patient Care Center is your trusted, go-to source for timely, accurate breast health and breast cancer information, services and resources. Our navigators offer free, personalized support for you and your loved ones including education, emotional support, financial assistance, help accessing care and more. Get connected to a Komen navigator by contacting the Breast Care Helpline at 1-877-465-6636 or email helpline@komen.org to get started. All calls are answered Monday through Thursday, 9 a.m. to 7 p.m. ET and Friday, 9 a.m. to 6 p.m. ET. 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 screening results are abnormal, and 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 03/17/25

This content is regularly reviewed by an expert panel including researchers, practicing clinicians and patient advocates.