CMS Pub. 100-04, ch. 18, § 20.6

A radiologist who interprets a screening mammography is allowed to order and interpret additional

films based on the results of the screening mammogram while a beneficiary is still at the facility for

the screening exam. When a radiologist’s interpretation results in additional films, Medicare will

pay for both the screening and diagnostic mammogram.

A/B MACs (B) Claims

For A/B MACs (B) claims, providers submitting a claim for a screening mammography and a

diagnostic mammography for the same patient on the same day, attach modifier “-GG” to the

diagnostic mammography. A modifier “-GG” is appended to the claim for the diagnostic

mammogram for tracking and data collection purposes. Medicare will reimburse both the

screening mammography and the diagnostic mammography.

A/B MAC (A) Claims

A/B MACs (A) require the diagnostic claim be prepared reflecting the diagnostic revenue code

(0401) along with HCPCS code 77065*(G0206*), 77066*(G0204*), or G0279 and modifier “-GG”

“Performance and payment of a screening mammogram and diagnostic mammogram on the same

patient, same day.” Reporting of this modifier is needed for data collection purposes. Regular

billing instructions remain in place for a screening mammography that does not fit this situation.

Both A/B MACs (A) and (B) systems must accept the GH and GG modifiers where appropriate.

* For claims with dates of service prior to January 1, 2017 thru December 31, 2017, providers

report CPT codes G0206 and G0204. For claims with dates of service January 1, 2018 and later,

providers report CPT codes 77065 and 77066 respectively.