Laura Summy, CPC, CRC Jul 14, 2021 6:09:22 AM 4 min read

Assistant At Surgery Documentation

Each month, our team addresses a common coding question to help you simplify your billing process. This month, we’re breaking down the details you should know about Assistant at Surgery Documentation.

There is more to documentation for Assistant At Surgery (AAS) billing than just listing the assistant’s name. An assistant at surgery is a physician who actively assists the physician in charge of a case in performing a surgical procedure. It must involve more than just ancillary services, and the documentation should state exactly what part of the service was performed by the AAS.

Below are important reminders for Assistant At Surgery billing:

Assistant At Surgery Modifiers

  • Modifier 80 is used when the service was provided by a medical doctor (MD).
  • Modifier 81 is used to identify minimum surgical assistant services and is only submitted with surgery codes.
  • Modifier 82 is used when the Assistant At Surgery service was provided by an MD and there was not a qualified resident available. The documentation must include information relating to the unavailability of a qualified resident in this situation.
  • Modifier AS is used for services provided by a physician’s assistant (PA), nurse practitioner (NP), or clinical nurse specialist (CNS).

Assistant At Surgery Indicators

  • 0 – payment restrictions for AAS applies to this procedure unless supporting documentation is submitted to establish medical necessity.
  • 1 – statutory payment restriction for AAS applies to this procedure; the AAS may not be paid.
  • 2 – payment restrictions for AAS does not apply to this procedure; the AAS may be paid.

Assistant At Surgery Reimbursement

  • Reimbursement equals 16% of the usual contracted rate.
  • Medicare allows 85% of the 16% for the AAS services provided by a PA, NP, or CNS.

Successful coding and billing for surgical assistants depends on whether the payer allows additional payment for assistance on the procedure, whether the surgeon correctly documents the need and role of the assistance, and whether the correct modifier has been added to the procedure code.

Please remember that just because a surgeon recruits an extra pair of hands to help during a surgical procedure doesn’t mean the payer will reimburse the assistant’s efforts. Surgical assistance must be deemed medically necessary (per the payer’s standards) to warrant additional payment.

Still have questions about Assistant At Surgery documentation or other coding scenarios? Our team is happy to help. Reach out to Laura Summy at for support.

Laura Summy is Managing of coding of MMG Healthcare Solutions / Medic Management Group. MMG is a national provider of consulting services and back office administrative support to independent and system owned physician practice groups.  Additionally, MMG has been formally recognized as a multi-year Northeast Ohio Top Workplaces award winner.