Claims for 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.

MACs 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” (Assistant Surgeon), “-81” (Minimum assistant surgeon), “-82” (Assistant surgeon (when qualified resident surgeon not available)), or the AS modifier (physician assistants, nurse practitioners and clinical nurse specialists), are subject to the assistant-at surgery policy. Accordingly, Medicare pays 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-atsurgery 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.

Method II Critical Access Hospitals (CAHs) assistant-at-surgery services rendered by a physician or nonphysician practitioner that has reassigned their billing rights to a Method II CAH are payable by Medicare when the procedure is billed on type of bill 85X with revenue code (RC) 96X, 97X, or 98X and an appropriate assistant-at-surgery modifier.

For more details, refer to MLN Matters® Article MM6123, “Payment of Assistant-at-Surgery Services in a Method II Critical Access Hospital (CAH).”

For more information, refer to the Medicare Claims Processing Manual, Chapter 12, Section 20.4.3.