Providers still struggle with accurate coding and documentation for screening versus diagnostic mammograms. An expert explains how to avoid unnecessary payment denials.

The Centers for Disease Control and Prevention (CDC) reports that each year, nearly 200,000 women will be diagnosed with breast cancer and more than 40,000 women will die of this disease.1

Given the benefits of early detection and intervention, Medicare, as well as private insurance payors, have long covered the cost of both diagnostic and screening mammograms, and in fact, many insurance carriers follow Medicare coverage provisions. However, while coverage has been in place for more than a decade, providers still struggle with accurate coding and documentation for screening versus diagnostic mammograms, leading to unnecessary payment denial due to common misunderstandings about the differences between the two services.

The Medicare program provides for coverage of screening mammograms for women with no signs or symptoms of breast disease for the purpose of early detection of breast cancer. Mammography coverage includes both the screening mammogram itself as well as the physician’s interpretation of the mammogram images. Medicare coverage for screening mammograms applies under the following circumstances:

  • Under age 35 (ie, women who qualify for Medicare coverage due to a disability): No payment is allowed for screening mammograms;
  • Women age 35 to 39 (again, Medicare enrollment due to a disability): One baseline screening mammogram between the woman’s 35th and 40th birthday;
  • Women age 40 and over: One annual screening mammogram in a 12-month period.
Julie Chicoine, Esq, RN, CPC

Screening mammograms do not require a physician’s order/prescription or a physician referral. There is no Medicare Part B deductible; however, a 20% coinsurance is expected.

Codes for Screening Mammograms include:

77057 – Screening mammography, bilateral (2-view film study of each breast)

+77052 – Add-on Code: computer-aided detection (computer algorithm analysis of digital image data for lesion detection) with further physician review for interpretation, with or without digitization of film radiographic images, screening mammography (list separately in addition to code for primary procedure)

G0202 – Screening mammography, producing direct digital image, bilateral, all views

(Note that CPT codes for mammography services prior to January 1, 2007, are no longer in use.)

While a screening mammogram is covered only annually, diagnostic mammograms are episodic and covered based on documented medical necessity. Unlike the screening mammogram, which takes place when women have no signs or symptoms of breast disease, a diagnostic mammogram is considered medically necessary when a woman presents with breast disease symptoms or in follow-up to abnormal findings in a screening mammogram. Medicare covers a diagnostic mammogram when performed on patients who meet one or more of the following criteria2:

  • Clinical signs or symptoms of breast disease, including abnormal findings on a screening mammogram that requires more in-depth evaluation.
  • A personal history of breast cancer; or
  • A patient is asymptomatic, but based on the patient’s history and other factors the physician considers significant, the physician’s judgment is that a mammogram is appropriate.

All diagnostic mammograms require a doctor’s order/prescription or referral to demonstrate that the service is “medically necessary” for Medicare coverage. Coverage will include not only the mammogram but the physician interpretation service as well.

Codes for Diagnostic Mammograms:

77055 – Diagnostic mammography, unilateral

77056 – Diagnostic mammography, bilateral

+77051 – Add-on Code: computer-aided detection (computer algorithm analysis of digital image data for lesion detection) with further physician review for interpretation, with or without digitization of film radiographic images, diagnostic mammography (list separately in addition to code for primary procedure)

G0204 – Diagnostic mammography, direct digital image, bilateral, all views

G0206 – Diagnostic mammography, producing direct digital image, unilateral, all views

The following common scenarios can cause confusion in coding and reimbursement for mammography services.

Patient Self-Referral and Timing of Last Mammogram

Because patients may self-refer and schedule a screening mammogram without the need for a physician order or referral, the period of time between examinations can be one of the more challenging reimbursement issues to resolve. Medicare regulations recommend that when scheduling annual screening mammograms, the office staff should count the months between mammography examinations beginning with the month after the date of the last examination.3 For example, if a patient received a screening mammogram in January 2009, office staff should begin counting the next month, February 2009, until 11 months have lapsed. The patient’s next eligible screening mammogram would take place sometime in January 2010.

Unclear Physician Order or Referral

While a physician order or referral is not required for screening mammograms, it is not unusual for physicians to write such orders out of professional habit. Confusion then arises when a patient presents for mammography services and the order is unclear as to whether a screening or diagnostic mammogram has been requested. Proactively, physician office staff can help avoid confusion and minimize payment denial by reminding ordering physicians to include a clear indication of the type of mammogram (screening versus diagnostic) that they are requesting before the patient leaves the office. Additional information helpful for mammography staff and radiologists would include the date of last screening exam (if known) as well as any relevant clinical information (ie, pertinent medical history) that will facilitate the radiologist’s subsequent review and interpretation. Beginning October 1, 2003, Medicare has denied payment for screening mammography claims with no diagnostic codes.

ICD-9 Codes that support medical necessity for screening mammograms include:

  • V76.11 – Screening mammogram for high-risk patient
  • V76.12 – Other screening mammography

Providers should report these ICD-9 codes as principal diagnosis codes if the screening mammography is the only service reported on the claim. Where the claim includes other services in addition to a screening mammography, the ICD-9 codes should be reported as other diagnosis codes.

Same Patient, Same Day, Different Tests

On some occasions, a patient could undergo a screening mammogram but the radiologist subsequently determines that a diagnostic mammogram is needed as well. A radiologist who interprets a screening mammogram is allowed to order and interpret additional films based on the results of the screening mammogram while the patient is still at the facility. Medicare regulations provide that where a radiologist interpretation results in additional films, the mammography is no longer considered a screening exam for application of age and frequency standards or for payment purposes. Moreover, the additional films can be performed without an order from the referring physician.

To ensure payment for both the screening and diagnostic mammography tests, physicians should report the “GG” modifier reflecting that both a screening and diagnostic mammogram were performed on the same patient on the same day. The GG modifier should be submitted with the diagnostic mammography code to reflect that the encounter changed from a screening to a diagnostic test. Diagnosis codes for a diagnostic mammogram will vary according to each patient’s clinical situation.

To ensure payment, documentation supporting the medical necessity for this encounter, including relevant diagnosis codes, should be submitted with the claim as well.

Julie Chicoine, Esq, RN, CPC, is the Medical Center Compliance Director for The Ohio State University Medical Center, which includes a College of Medicine and Public Health, five hospitals, two freestanding research institutes, and a network of more than 30 community-based primary and specialty care facilities throughout central Ohio. She is also accredited as a certified professional coder by the American Academy of Professional Coders (AAPC).


  2. Medicare Claims Processing Manual, CMS Pub 100-04, Chapter 18, Section 20(B).
  3. Medicare Claims Processing Manual, CMS Pub. 100-04, Chapter 18, Section 20(A).