Physician Assistants at Surgery: Modifiers 80, 81, 82, and AS

Physician assistants at surgery: using Modifiers 80, 81, 82, and AS to get reimbursed.

Surgical Assistants – Getting Paid

When a surgical assistant is called in to help with part or all of a surgical procedure, that individual’s portion of the work needs to be reported with the usual CPT code, along with the appropriate physician modifier to show the status of the assistant. 

Payment for a surgical assistant, or assistant at surgery, is based on the CPT coding guidelines and the policies set by Medicare and non-Medicare payers. The operative report must also include the name and title of the surgical assistant, the specific services performed, and the reason they were medically necessary. Without this critical information, a third-party payer will likely deny the claim.   

Primary Surgeon’s Responsibility

The primary surgeon has the responsibility to determine and request the assistance of a qualified practitioner at surgery and to determine the level of care the assistant will provide. The decision on the type of professional who may be asked to assist in the surgery may be based on local resources and the characteristics of the patient. For some surgeries, a second assistant at surgery may be necessary.

Surgical Assistant Definition

According to the American College of Surgeons (ASC), “The first assistant in a surgical operation should be a trained individual 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 (prevent or stop the bleeding), and serve other technical functions. The qualifications of the person in this role may vary with the nature of the operation, the surgical specialty, and the type of hospital or ambulatory surgical facility.”

The surgical assistant also performs preoperative and postoperative duties to ensure proper patient care. During a surgical procedure, the assistant works under the direct supervision of the primary surgeon and in accordance with hospital policy and relative laws and regulations. 

The first assistant at surgery should preferably be either a qualified surgeon or a resident of an approved surgical training program. If these assistants are unavailable, other qualified physicians may be called on to lend a helping hand. 

There are times when nonphysicians, such as surgeon assistants (SAs) or physician assistants (PAs), may be needed as first assistants. These individuals must have the appropriate surgical training, be credentialed by the appropriate local authority, and may not operate independently. 

Registered nurses may serve as first assistants if they have specialized training. They may not function in two different capacities simultaneously, however, such as a scrub nurse and instrument nurse while serving as a first assistant.   

What is a Modifier?

A modifier is a two-digit code that may be appended to CPT or HCPCS Level II codes. It conveys to the payer additional information about a procedure or service performed by a physician or other qualified healthcare provider as to how the code descriptor has changed but not enough to alter the definition or code. According to the CPT coding manual, a modifier is also used by healthcare professionals to effectively respond to payment policy requirements established by other entities.  

Assistant Surgeon Modifiers (80, 81, 82, and AS)

Modifiers used to report surgical services performed by an assistant include CPT modifiers -80, -81, -82, and HCPCS Level II modifier -AS. These modifiers are added to the same CPT procedure code that the primary surgeon uses. The modifier tells the third-party payer of the assistant surgeon’s status. 

CPT modifiers -80, -81, and -82 and their descriptions are listed in Appendix A of the CPT coding manual as: 

  • Modifier -80, Assistant surgeon: Surgical assistant services may be identified by adding modifier -80 to the usual procedure number(s).  
  • Modifier -81, Minimum assistant surgeon: Minimum surgical assistant services are identified by adding modifier -81 to the usual procedure number.
  • Modifier -82, Assistant surgeon (when a qualified resident surgeon is not available): The unavailability of a qualified resident surgeon is a prerequisite for use of modifier -82 appended to the usual procedure code number(s). 

HCPCS modifier -AS and its description is usually listed in an appendix of the HCPCS Level II coding manual as: 

Modifier -AS, Physician assistant, nurse practitioner, or clinical nurse specialist services for assistant at surgery: When a physician assistant provides a helping hand at surgery, HCPCS modifier -AS would be appended to the CPT code, rather than modifier -80. 

Payment on These Modifiers

Modifier -80: An assistant surgeon actively assists a primary surgeon for all or a significant portion of the surgical procedure. When modifier -80 is used, the third-party payer usually pays 15 to 30% of the usual charge for a surgery; however, not all payers allow for an assistant surgeon for all procedures. Before performing a surgery, a pre-authorization should be completed to find out if the payer will reimburse for the assistant surgeon.  

Modifier -81: Although not commonly used, this modifier is used when a minimum assistant surgeon provides services for only a portion of the procedure. These services are less extensive than those described by modifier -80. Many third-party payers do not reimburse for a minimum assistant surgeon. Medicare rarely pays a minimum assistant surgeon, and that is only when medical necessity can be proven. The payment for a minimum assistant surgeon is usually 10% of the usual charge for a surgery. 

The CPT coding manual defines a minimal assistant surgeon as a physician acting in a minimal capacity. However, some third-party payers define a minimal assistant surgeon differently. They consider a minimal assistant surgeon as a nurse practitioner, physician’s assistant, or other specialized clinical nursing personnel. For this reason, the coder should be sure to check with the third-party payer before reporting modifier -81 for individuals other than a physician.

Modifier -82: This modifier is used when the hospital where the procedure was performed is affiliated with a medical school and has a residency program, but no resident is available to assist at surgery. These hospitals provide surgical training to their residents, who are physicians, in return for providing assistance to physicians. Medicare does not pay for an assistant surgeon if the hospital has a residency program. Supporting documentation must indicate that the patient’s condition required an assistant surgeon and that a qualified resident was not available. 

Modifier -AS: Coders should review the CMS Medicare Physician Fee Schedule (MPFS) to determine if a procedure is reimbursable when performed by a surgical assistant. Some non-Medicare payers do not accept modifier -AS.  

Medicare as the Payer

CMS has developed the Medicare Physician Fee Schedule which specifies the services they cover. It also indicates which procedures are eligible for payment when performed by an assistant surgeon. 

The coder enters a CPT code into the Fee Schedule, and one of the following Assist-at-surgery surgical indicators are provided: 

  • 2:  Assistant at surgery may be paid
  • 0:  Additional documentation is needed to substantiate medical necessity
  • 1:  Assistant surgeon will not be paid
  • 9:  Assistant surgeon concept does not apply

So, let’s assume that the documentation states that an assistant surgeon assisted the primary surgeon in performing a single lung transplant, and the correct CPT code is 32851, Lung transplant, single; without cardiopulmonary bypass. The coder could enter this code into the Physician Fee Schedule, and a table would appear with the CPT code listed (32851), along with a short description (Lung transplant single), and the assist-at-surgery indicator (2). Indicator “2” means that Medicare allows for payment for a surgical assistant in this procedure. The coder would then report 32851 with the appropriate modifier appended based on the documented surgical assistant’s status.  

Non-Medicare Payers

Non-Medicare payers have their own payer policies, which may be different from the policy set by Medicare. United Healthcare’s Reimbursement Policy states that the standard reimbursement for eligible assistant-at-surgery services, which are provided by a physician (MD or DO), is 16% of the allowable amount. The standard reimbursement for eligible assistant-at-surgery services, which are provided by a healthcare professional, is 14% of the allowable amount. A physician assistant, clinical nurse specialist, or nurse practitioner is someone who does not have an MD or DO degree/designation. A surgical technician assisting at surgery is included in the reimbursement to the facility and is not separately reimbursable. 


Although there is no guarantee of payment for an assistant’s efforts, including certain information in the operative report certainly increases the chances. The primary surgeon’s operative report should explain the services performed, and the individuals, including credentials, who performed them. The body of the report should indicate the specific responsibilities assigned to the assistant surgeon in which he/she actively participated during the surgical procedure, and the reason assistance was needed. In addition, all services performed by a surgical assistant must meet the criteria for medical necessity and must be included in the documentation.   

Modifier Exercise

Using what you have learned about modifiers -80, -81, -82, and -AS, identify the modifier in the following questions:

  1. Dr. Blue serves as a surgical assistant to Dr. Green in a coronary artery bypass graft procedure. The patient experiences complications during the procedure. Dr. Green requests that Dr. White come to the operating room to help with the surgery to stabilize the patient. What modifier would be used to report Dr. White’s part of the service?
  2. Patient presents with a lung hernia that is bulging through the chest wall. It requires immediate repair. This is a teaching hospital, and the residents on call are busy assisting in other procedures. Therefore, the primary surgeon requests the assistance of another thoracic surgeon for the procedure. The assistant surgeon would report his portion of the procedure with which modifier?
  3. A physician assistant is asked to assist at surgery. What modifier is used to report the physician assistant’s services?
  4. A primary surgeon performs a posterior cervical arthrodesis at C5-C6. The assistant surgeon helps in holding the vertebrae in place and with harvesting and placement of the bone graft. What modifier would the assistant surgeon append to the CPT code to report his part of the procedure? 


  1. CPT modifier -81
  2. CPT modifier -82
  3. HCPCS modifier -AS
  4. CPT modifier -80

I wrote the above article for BC Advantage (, which was recently published in their magazine. It is being reprinted here with their permission. 

physician assistants helping out primary surgeon so they can get paid and the need to add modifiers 80, 81, 82, and AS to the CPT code to get paid


American College of Surgeons (ASC) Statements on Principles
Physicians as Assistants at Surgery: 2020 Update

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