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Key Points for Assistant-at-Surgery Billing

Key-Points-for-Assistant-at-Surgery-Billing

Assistant surgeon billing can seem overwhelming, so it’s crucial to take it one step at a time. But there are several key points to remember that will make it much easier to understand.

Assistant at Surgery:

An assistant at surgery is a physician or non-physician practitioner who actively assists the surgeon and goes beyond providing ancillary services. Under some circumstances, when a procedure doesn’t require the skill of a second surgeon, but either the patient’s condition or surgical complexity requires an assistant, the services of the assistant at the surgery are reimbursable. A physician (MD) assistant surgeon is paid 16% of the reimbursement for the applicable surgical CPT code. For non-physicians (e.g. physician assistants, nurse practitioners, or clinical nurse specialists), acting as an assistant at surgery, this amount is further reduced to 13.6% of the surgical reimbursement.

Code the Lead Surgery Claim First:

Code the main/lead surgery claim first. Once that is completed, look at the Assistant at Surgery Indicators on the CMS Medicare Physician Fee Schedule (MPFS) site to see if an assistant is allowed for the surgery being billed. You will see one of the following indicators:

  • 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.

Review the Report:

Review the operative report again, ensuring the name and credentials of the assistant surgeon are documented. Some MACs require that the role of the assistant also be documented (what did the assistant do during the procedure), so check yours to be sure. If the surgery took place at a teaching hospital, the operative report must also include the statement, ‘No qualified resident was available to assist.’ If there was a resident available, and/or one was assisting, then an assistant surgeon is not reimbursable.

Lead Surgeon Billing:

The main/lead surgeon is billed on one claim; the assistant surgeon is billed on a separate claim, under his/her own name. The assistant surgeon claim should include one of the following modifiers:

  • 80 — Assistant Surgeon:

    This modifier is for physician’s services only. A physician’s surgical assistant services may be identified by adding the modifier 80 to the surgical 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 is for physician’s services only. Minimal surgical assistance may be identified by adding the modifier 81 to the surgical 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 is for 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 an assistant at surgery:

    This modifier applies when the assistant at surgery services are provided by a PA, APNP, or CNS.

Medicare Reimbursement:

Medicare assistant surgeon claim is reimbursed at 16% of the CMS MPFS rate unless billed with the AS modifier, which is reimbursed at 14%. Medicaid and Commercial carriers may reimburse differently.

If you take things one step at a time, you can figure out whether or not an assistant surgeon service meets the criteria to be billed for a particular service, and if so how that claim should look. It is a complex task, but breaking it down makes it easier to understand and in turn leads to correct, successful billing.

FAQs on Assistant Surgeon Billing

1. What is an assistant at surgery?
An assistant at surgery is a physician or non-physician practitioner who actively helps the lead surgeon beyond providing ancillary services. Their assistance is reimbursable when the procedure doesn’t require a second surgeon, but due to the patient’s condition or surgical complexity, an assistant is necessary.


2. How much does Medicare reimburse for assistant surgeons?
Medicare reimburses physician (MD) assistant surgeons at 16% of the applicable surgical CPT code. For non-physician providers, such as physician assistants, nurse practitioners, or clinical nurse specialists, the reimbursement is reduced to 13.6%.


3. What should be coded first when billing for an assistant surgeon?
The main surgery (lead surgeon) claim should be coded first. After that, check the CMS Medicare Physician Fee Schedule (MPFS) to see if an assistant surgeon is allowed for the procedure based on the following indicators:

  • 0: Payment restriction applies unless medical necessity is established.
  • 1: Statutory payment restriction applies, and the assistant surgeon cannot be paid.
  • 2: Payment restriction does not apply; the assistant surgeon may be paid.
  • 9: The concept does not apply.

4. What documentation is required for assistant surgeon billing?
Ensure the operative report includes the name and credentials of the assistant surgeon. Some MACs require documentation of the assistant’s role during the procedure. For teaching hospitals, the report must state that no qualified resident was available, or the assistant surgeon will not be reimbursed.


5. Which modifiers are used for assistant surgeon billing?
Use one of the following modifiers when billing for assistant surgeon services:

  • 80: For physicians providing full assistance at surgery.
  • 81: For physicians providing minimal assistance at surgery (not commonly used in Medicare billing).
  • 82: For physicians assisting when a qualified resident is unavailable at a teaching facility.
  • AS: For non-physician providers (e.g., PA, APNP, CNS) acting as assistants at surgery.

6. How do Medicare and commercial insurers reimburse for assistant surgeons?
Medicare reimburses physician assistant surgeons at 16% of the CMS MPFS rate. For non-physician providers billed with the AS modifier, the reimbursement is 14%. Medicaid and commercial insurers may have different reimbursement rates.


7. How is the billing process for assistant surgeons in a teaching facility different?
In teaching facilities, if a resident is available to assist, an assistant surgeon is not reimbursable. If no qualified resident is available, use modifier 82, and the operative report must document the resident’s unavailability.


8. How are lead surgeon and assistant surgeon claims submitted?
The lead surgeon’s claim is submitted first, and the assistant surgeon’s claim is submitted separately under their own name.

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