ASC Ancillary Services (CMS Addendum BB)
This hub covers CPT and HCPCS codes that CMS lists on Addendum BB, the set of covered ancillary services for Ambulatory Surgery Centers. These are not the surgical procedures themselves. They are the imaging, guidance, drugs, and other integral services that support a covered surgery. Codes here include things like ultrasound guidance for a biopsy (76942) and needle localization by X-ray (77002), the kinds of services that accompany a primary procedure rather than stand alone as the reason for the visit.
For an ASC, the practical point is how these services are paid. Many ancillary services are packaged into the payment for the surgical procedure they support, which means the ASC does not receive a separate line-item payment for them under Medicare. Some ancillary services are paid separately. The Addendum BB designation tells you the service is recognized as covered in the ASC setting, but it does not by itself tell you whether a given line will be paid separately or bundled. That distinction drives whether it is worth reporting on the claim and what to expect on the remittance.
Billers should read this category as a reminder to check the payment indicator behind each code, confirm the service is tied to a covered surgical procedure, and document medical necessity for the guidance or imaging performed. Codes carrying a T (Category III) suffix, such as 0331T for planar cardiac sympathetic imaging or 0422T for tactile breast imaging, often have payer-specific or investigational treatment, so verify coverage before scheduling. DataLily's procedure library tracks CPT-specific prior authorization and documentation requirements so these checks happen before the case, not after a denial.
ASC Ancillary Services codes(showing 120 of 2,526)
What does Addendum BB mean for an ASC?
Addendum BB is the CMS list of covered ancillary services in the Ambulatory Surgery Center setting. It identifies imaging, guidance, drugs, and other services that are integral to a covered surgery. Being on Addendum BB means Medicare recognizes the service in the ASC, but the payment indicator on the code determines whether it is paid separately or packaged into the payment for the surgical procedure.
Are ancillary services like imaging guidance paid separately in an ASC?
It depends on the code. Some ancillary services, such as certain imaging or guidance lines like 76942 or 77002, are packaged into the ASC payment for the procedure they support, so the ASC does not receive a separate payment. Others are paid separately. Check the ASC payment indicator for each code rather than assuming, and confirm the service ties to a covered primary procedure.
Why are some ancillary codes labeled investigational or payer-specific?
Many Category III codes, which end in the letter T, describe newer or emerging services. Examples include 0331T for cardiac sympathetic imaging and 0422T for tactile breast imaging. Payers often treat these as investigational or apply their own coverage criteria, so coverage and payment can vary. Verify the specific payer's policy and document medical necessity before performing and billing the service.