Modifiers 80, 81, 82, AS; Assistant at Surgery

Policy ID: Mod 109

Section: Modifiers

Effective Date: January 01, 2027

Last Reviewed: June 29, 2026

Applies To: Migrated Commercial

This policy applies only to physicians and other qualified health care professionals.

Definitions

Code/Term

Code Description/Term Definition

Assistant Surgeon

Physician or other non-physician practitioner (NPP) who actively assists the primary surgeon performing a surgical procedure.

Current Procedural Terminology (CPT^®) Modifier 80 represents

Represents assistant at surgery by another physician. This assistant at surgery provides full assistance to the primary surgeon. This modifier is not intended for use by non-physicians assisting at surgery (e.g., Nurse Practitioners or Physician Assistants/Physician Associates).

CPT Modifier 81

Represents minimal assistant at surgery by another physician. This assistant at surgery provides minimal assistance to the primary surgeon. This modifier is not intended for use by non-physicians assisting at surgery (e.g., Nurse Practitioners or Physician Assistants/Physician Associates).

CPT Modifier 82

Represents assistant at surgery by another physician when a qualified resident surgeon is not available to assist the primary surgeon. This modifier is not intended for use by non-physicians assisting at surgery (e.g., Nurse Practitioners or Physician Assistants/Physician Associates).

Healthcare Common Procedure Coding System (HCPCS) Level II Modifier AS

Represents a non-physician assisting at surgery (e.g., Nurse Practitioners or Physician Assistants/Physician Associates).

Assistant at Surgery Indicators

The Centers for Medicare & Medicaid Services (CMS) Assistant at Surgery Indicators (ASST SURG) are found in the CMS National Physician Fee Schedule Relative Value File (NPFSRVF). Values, which are currently in the CMS NPFSRVF, are:

Assistant surgeon may be paid with documentation supporting medical necessity.

Assistant surgeon cannot be paid

Assistant surgeon can be paid

Assistant surgeon concept does not apply

Policy Statement

Our health plan will reimburse physicians and certain non-physician providers for assistant at surgery when the procedure code has been assigned a CMS Assistant at Surgery Indicator 2.

In the absence of a CMS Assistant at Surgery Indicator, our health plan may establish an assistant at surgery designation. Our health plan may employ Milliman Clinical Guidelines (MCG) in determining medical necessity for assistant at surgery.

All licensed providers must bill for all services they perform under their own name. A provider may not submit claims for services performed by another licensed provider.

Physicians billing as assistant at surgery must assign modifier 80, 81, or 82.

Non-physician providers billing as assistant at surgery must assign modifier AS. Our health plan will reimburse for assistant at surgery when the non-physician provider is a nurse practitioner, physician assistant/physician associate or clinical nurse specialist. Other provider types, including but not limited to a registered or certified registered nurse or certified surgical technician will not be reimbursed for assistant at surgery.

Major surgical procedures billed by non-physician providers without an assistant at surgery modifier of 80, 81, 82 or AS appended to the claim line are not reimbursable.

The assistant at surgery must report the same codes as the surgeon. An exception to this is when the surgeon bills a global code (e.g., maternity care). In that case, the assistant at surgery must bill the specific surgery code (e.g., delivery only). The same multiple procedure fee reductions and clinical edits apply to the assistant at surgery as the primary surgeon.

When multiple procedures are performed where only some of the codes are eligible for assistant at surgery reimbursement, only the eligible codes will be reimbursed to the provider billing for the assist.

We will only reimburse for one assistant at surgery. We will not reimburse two assistants at surgery at the same surgery. In addition, our health plan will not reimburse for an additional assistant at surgery on a procedure where reimbursement has been provided as co-surgeons.

When a provider reports an eligible procedure with modifier 80, 81 or 82 appended, reimbursement will be 20% of the allowable amount.

When a provider reports an eligible procedure with modifier AS appended, reimbursement will be 17% of the allowable amount.

References

Centers for Medicare & Medicaid Services (CMS), National Physician Fee Schedule Relative Value File
American Medical Association. “Appendix A: Modifiers” Current Procedural Terminology (CPT®). AMA Press
CMS Manual System

Cross References

Mod 113 – Modifier 62; Two Surgeons/Co-Surgeons
Med 107 – Maternity Care

Disclaimer

Your use of this Reimbursement Policy constitutes your agreement to be bound by and comply with the terms and conditions of the Reimbursement Policy Disclaimer.

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