Assistant Surgeon Modifiers

Modifier 80, 81, 82: Denote assistant surgeons. Should be submitted on those surgical procedures where an assistant surgeon is warranted. NOTE: Physicians acting as assistants cannot bill as co-surgeons. Benefits will be derived based on CMS designation for Assistant Surgeon.

Supervision of Physician Assistant, Advanced Practice Nurse or Certified Registered Nurse First Assistant

The following modifiers should be used by the supervising physician when he/she is billing for services rendered by a Physician Assistant (PA), Advanced Practice Nurse (APN) or Certified Registered Nurse First Assistant (CRNFA):

AS Modifier: A physician should use this modifier when billing on behalf of a PA, APN or CRNFA for services provided when the aforementioned providers are acting as an assistant during surgery. (Modifier AS to be used ONLY if they assist at surgery)

SA Modifier: A supervising physician should use this modifier when billing on behalf of a PA, APN, of CRNFA for non-surgical services. (Modifier SA is used when the PA, APN, or CRNFA is assisting with any other procedure that DOES NOT include surgery.)

–80 Modifier: PA’s, APN’s, and CRNFA’s who are billing with their own National Provider Identifier (NPI) will not need to bill a modifier, unless they are billing as an Assistant Surgeon, then they must use the –80 modifier.


Appropriate use of assistant at surgery modifiers and payment indicators

First Coast Service Options Inc. (First Coast) would like to remind providers within jurisdiction N (JN) of the appropriate use of assistant at surgery modifiers and payment under the Medicare physician fee schedule (MPFS).

An assistant at surgery is a provider who actively assists the physician in charge of a case in performing a surgical procedure. A physician, nurse practitioner, physician assistant or clinical nurse specialist who is authorized to provide such services under state law can serve as an assistant at surgery.

Medicare considers advanced registered nurse practitioner (ARNP), physician assistant (PA), and clinical nurse specialist (CNS) as non-physician practitioners. Medicare does not recognize a registered nurse first assistant (RNFA) as a qualified Medicare provider.

To report services of an assistant surgeon, the following surgical modifiers should be appended:

• 80 — Assistant Surgeon: This modifier pertains to physician’s services only. A physician’s surgical assistant services may be identified by adding the modifier 80 to the usual procedure code. This modifier describes an assistant surgeon providing full assistance to the primary surgeon, and is not intended for use by non-physician providers.

• 81 — Assistant Surgeon: This modifier pertains to physician’s services only. Minimal surgical assistance may be identified by adding the modifier 81 to the usual procedure code, and describes an assistant surgeon providing minimal assistance to the primary surgeon. This modifier is not intended for use by non-physician providers.

Note: This modifier is used in the private insurance industry and is not commonly used in Medicare billing.

• 82 — Assistant surgeon (when a qualified resident surgeon is not available in a teaching facility): This modifier applies to physician’s services only. The unavailability of a qualified resident surgeon is a prerequisite for use of this modifier and the service must have been performed in a teaching facility. The circumstance explaining that a resident surgeon was not available must be documented in the medical record. This modifier is not intended for use by non-physician providers.

• AS — Non-physician provider as assistant at surgery: This modifier applies when the assistant at surgery services are provided by a PA, ARNP, or CNS.

Payment information

Medicare reimburses services rendered for assistant at surgery by a physician performing as a surgical assistant at 16 percent of the MPFS amount. Services rendered for assistant at surgery by non-physician providers are reimbursed at 85 percent of 16 percent (i.e., 13.6 percent) of the MPFS amount.

When reporting services provided by non-physician practitioners acting as assistants at surgery, append modifier AS to the procedure code used to report the surgeon’s service.

If a physician appends modifier AS to procedure codes for which he/she acted as assistant at surgery, these codes will be denied (see above for modifiers that should be used by physicians).

Medicare physician fee schedule database (MPFSDB) assistant at surgery payment indicators

The MPFSDB is a file layout that carriers and A/B MACs use to display the total fee schedule amount, related component parts, and payment policy indicators. The assistant at surgery payment indicator describes when assistant at surgery may be paid or not. Valid indicators are:

• 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. Assistant at surgery may be paid.

• 9 = Concept does not apply.

If multiple services are submitted with modifiers indicating assistants at surgery, each service is independently reviewed (based on the above-listed indicators) to determine payment.



Assistant-at Surgery-Services

For assistant-at-surgery services performed by physicians, the fee schedule amount equals 16 percent of the amount otherwise applicable for the surgical payment.

Contractors may not pay assistants-at-surgery for surgical procedures in which a physician is used as an assistant-at-surgery in fewer than five percent of the cases for that procedure nationally. This is determined through manual reviews.

Procedures billed with the assistant-at-surgery physician modifiers -80, -81, -82, or the AS modifier for physician assistants, nurse practitioners and clinical nurse specialists, are

subject to the assistant-at-surgery policy. Accordingly, pay claims for procedures with these modifiers only if the services of an assistant-at-surgery are authorized.

Medicare’s policies on billing patients in excess of the Medicare allowed amount apply to assistant-at-surgery services. Physicians who knowingly and willfully violate this prohibition and bill a beneficiary for an assistant-at-surgery service for these procedures may be subject to the penalties contained under §1842(j)(2) of the Social Security Act (the Act.) Penalties vary based on the frequency and seriousness of the violation.