Oncology & Hematology Coding Alert

Here’s how to navigate the Medicare minefield.

For such a significant, high volume, yet simple procedure, mammograms generate an awful lot of coding questions. Chief among them are questions about the different reasons for the procedure, how and why Medicare and private payer rules about eligibility requirements differ, and which ICD-10-CM codes you should use to support the medical necessity for the procedure.

Here, then, are the answers to all your mammography coding questions in one handy FAQ.

What Is the Difference Between a Screening and a Diagnostic Mammogram?

Understanding these terms is important from a coding perspective as they determine the exact ICD-10-CM codes you will use to justify medical necessity for the procedures.

A screening mammogram is “a radiologic procedure provided to an asymptomatic woman for the purpose of early detection of breast cancer and includes a physician’s interpretation of the results of the procedure. Unlike diagnostic mammographies, there do not need to be signs, symptoms, or history of breast disease in order for the exam to be covered,” according to the Medicare Benefit Policy Manual (Chapter 15, section 280.3 www.cms.gov/Regulations-and-Guidance/Guidance/Manuals/Downloads/bp102c15.pdf).

A diagnostic mammogram is furnished to a patient who is showing signs, or who has a personal or family history of, breast cancer.

What Mammography Codes Do I Use?

The relevant CPT^® codes are:

• 77065 (Diagnostic mammography, including computer-aided detection [CAD] when performed; unilateral)
• 77066 (… bilateral)
• 77067 (Screening mammography, bilateral [2-view study of each breast], including computer-aided detection [CAD] when performed)

Remember: The codes have laterality built into their descriptors, so you don’t need to use laterality modifiers LT (Left side), RT (Right side), or 50 (Bilateral procedure).

What Are the Mammogram Eligibility Requirements?

Medicare will not pay for screening mammograms for women less than 35 years’ old. But they will “pay for only one screening [baseline] mammography performed on a woman between her 35th and 40th birthday” and “for a screening mammography performed after 11 full months have passed following the month in which the last screening mammography was performed” for a woman over 39 (Medicare Benefit Policy Manual, Chapter 15, section 280.3).

For diagnostic mammograms, Medicare needs “a treating provider's (physician or qualified non-physician practitioner) referral.” The referral “should specify the diagnosis prompting the request for a diagnostic mammogram” (>www.cms.gov/medicare-coverage-database/view/lcd.aspx?lcdId=33950&ver=33).

Note this Medicare exception: No referral is necessary when the diagnostic mammogram is “performed at the discretion of the radiologist when prompted to do so by findings on the same day of the screening mammography).” Under these circumstances, “a note in the radiologist’s report will fulfill this provision.”

Unfortunately, “not all payers follow Medicare rules, guidelines, and fee schedules,” says Leslie Johnson, CPC, coding and auditing consultant at Oasis Medical and Surgical Wellness Group, LLC, in Glen Rock, New Jersey. This means you should thoroughly familiarize yourself with each private payer guideline before billing to make sure you don’t spend an excessive amount of time “coding, posting, researching and correcting, resubmitting a claim once, maybe even twice or more,” Johnson explains.

What if a Patient Does Not Meet Eligibility Requirements?

Medicare requires you to notify the patient that the services “are likely to be non-covered, whether for medical necessity or for other reasons” with an advance beneficiary notice of non-coverage (ABN). This means Medicare claims for 77067 should also be accompanied by one of the following modifiers as appropriate:

• GA (Waiver of liability statement issued as required by payer policy, individual case)
• GX (Notice of liability issued, voluntary under payer policy)
• GY (Item or service statutorily excluded, does not meet the definition of any Medicare benefit or, for Non-Medicare insurers, is not a contract benefit)
• GZ (Item or service expected to be denied as not reasonable and necessary) >www.cms.gov/medicare-coverage-database/view/article.aspx?articleid=56448&ver=13)

What Happens When a Screening Mammogram Leads to a Diagnostic?

If a patient receives both services on the same day, Medicare requires you report the services with modifier GG (Performance and payment of a screening mammogram and diagnostic mammogram on the same patient, same day) on the diagnostic mammography and modifier 59 (Distinct procedural service) or XU (Unusual non-overlapping service…) on the screening mammography (www.cms.gov/files/document/chapter9cptcodes70000-79999final11.pdf).

The modifiers will only be necessary if the two procedures are performed on the same date of service. Screening and diagnostic mammograms performed on different dates of service do not require either modifier.

What ICD-10-CM Codes Support Medical Necessity for Mammograms?

For screening mammograms billed with 77067 you will use Z12.31 (Encounter for screening mammogram for malignant neoplasm of breast) as the reason for the visit. This can be the first-listed code as “a screening code may be a first-listed code if the reason for the visit is specifically the screening exam” per section I.C.21.5.c of the ICD-10-CM guidelines.

For diagnostic mammograms billed with 77065 or 77066 you have a variety of diagnostic codes available to you depending on circumstances, including:

• C50.- (Malignant neoplasm of breast)
• D24.- (Benign neoplasm of breast)
• D48.6- (Neoplasm of uncertain behavior of breast)
• R92.- (Abnormal and inconclusive findings on diagnostic imaging of breast)
• Z08 (Encounter for follow-up examination after completed treatment for malignant neoplasm)
• Z85.3 (Personal history of malignant neoplasm of breast) (>www.cms.gov/medicare-coverage-database/view/article.aspx?articleid=56448&ver=13)

You would also use one of these codes if a screening mammogram leads to a diagnostic one.