Clinical UM Guideline

This document addresses use of an assistant during surgical procedures. An assistant at surgery refers to a licensed professional who actively participates with the operating surgeon who is performing a surgical procedure. This document does not address use of a co-surgeon or team of surgeons.

Medically Necessary:

Use of one assistant surgeon during a surgical procedure may be considered medically necessary when the following criteria are met:

1. The American College of Surgeons (ACS) has designated a procedure as “always” requiring an assistant surgeon; or
2. ACS has designated a procedure as “sometimes” requiring an assistant surgeon and the Centers for Medicare and Medicaid Services (CMS) have designated the procedure as “always” requiring an assistant surgeon; or
3. There is documented evidence that the procedure requires assistance due to the complexity of the procedure or health status of the individual and both the ACS and CMS have designated a procedure as “sometimes” requiring an assistant surgeon.

Not Medically Necessary:

The use of an assistant surgeon during surgery is considered not medically necessary for the following:

1. The surgical procedure is designated as “never” requiring an assistant surgeon by the ACS;
2. ACS has designated the procedure as “sometimes” requiring an assistant surgeon and CMS has designated the procedure as “never” requiring an assistant surgeon;
3. The procedure could be assisted by a surgical technician and there is no documented need for an assistant surgeon’s level of training and expertise.

ACS (2013) has defined an assistant surgeon as someone “who is able to participate in and actively assist the surgeon in completing the operation safely and expeditiously by helping to provide exposure, maintain hemostasis, and serve other technical functions.” An assistant surgeon generally refers to a medical doctor (MD), Doctor of Podiatric Medicine (D.P.M.), Doctor of Dental Surgery (D.D.S.), or Doctor of Osteopathy (D.O.). ACS indicates that at times, it may also be appropriate to use other licensed allied health professionals such as a physician’s assistant (PA), clinical nurse specialist (CNS), nurse practitioner (NP) or registered nurse first assistant (RNFA).

ACS has determined that assistant surgeon services are required for the successful completion of certain surgical procedures that have been identified as sufficiently complex or intensive in the sixth edition of their study, Physicians as Assistants at Surgery (2023*), which was developed in collaboration with 15 other specialty societies. The study was undertaken by examining all of the codes listed in the American Medical Associations (AMA) Current Procedural Terminology (CPT TM) 2020. The organizations in collaboration with the ACS, were asked to review each code and indicate if surgical procedures required the use of an assistant surgeon “almost always,” “almost never,” or “sometimes.”

Similar to the ACS, CMS has designated surgical procedures with verbiage akin to “always,” “sometimes,” or “never” requiring a surgical assistant based on the frequency of use documented in the CMS Medicare Physician Fee Schedule (MPFS) database in effect at the time of service (also referred to as the Relative Value File). The list is applicable to first assistants, MDs, PAs and NPs.

Assistant at Surgery
Indicates services where an assistant at surgery is never paid for per Medicare Claims Manual.
0=Payment restriction for assistants at surgery applies to this procedure unless supporting documentation is submitted to establish medical necessity.
1 = Statutory payment restriction for assistants at surgery applies to this procedure. Assistant at surgery may not be paid.
2 = Payment restriction for assistants at surgery does not apply to this procedure. Assistants at surgery may be paid.
9 = Concept does not apply [e.g., procedures during which use of an assist surgeon would not be considered].

*If there is a more recent version available of the ACS’s Physicians as Assistants at Surgery publication, it supersedes the version and link listed in the Reference section of this document.

Assistant surgeon: A practitioner who actively assists the operating surgeon. An assistant may be necessary because of the complex nature of the procedure(s) or the individual’s condition. The assistant surgeon is usually trained in the same specialty.

Co-surgeons: Two or more surgeons, where the skills of both surgeons are necessary to perform distinct parts of a specific operative procedure.

Team of surgeons: More than two surgeons, usually of different specialties, where the skills of each are necessary to perform distinct parts of a specific operative procedure.

Peer Reviewed Publications:

1. Deery SE, O'Donnell TFX, Zettervall SL, et al. Use of an assistant surgeon does not mitigate the effect of lead surgeon volume on outcomes following open repair of intact abdominal aortic aneurysms. Eur J Vasc Endovasc Surg. 2018; 55(5):714-719.
2. Kajiwara M, Ishii F, Sasaki T, et al. Crucial Roles of the Assistant Surgeon During Laparoscopic Left Hemihepatectomy. Cureus. 2022; 14(4):e24050.

Government Agency, Medical Society, and Other Authoritative Publications:

1. American College of Surgeons. Physicians as assistants at surgery: 2023 study. Available at: https://www.facs.org/media/gp3ny4ps/2023-update-physicians-as-assistants-at-surgery.pdf. Accessed on March 03, 2024.
2. Centers for Medicare and Medicaid Services. Physician Fee Schedule (PFS) Relative Value Files Available at: http://www.cms.gov/Medicare/Medicare-Fee-for-Service-Payment/PhysicianFeeSched/PFS-Relative-Value-Files.html. Accessed on March 03, 2024.