Prompt Proper Assistant-at-surgery Payment

By Marilyn Holley, CPC, CPC-I, RHIT, CHISP

It’s as easy, or as hard, as 1, 2, 3.

Successful coding and billing for surgical assistants depends on three principal factors:

  1. Does the payer allow additional reimbursement for surgical assistance for the reported procedure?
  2. Has the surgeon sufficiently documented the need for and role of the surgical assistant?
  3. Has the proper modifier been appended to the claim?

Here are some tips and techniques for ensuring your assistant-at-surgery claims prompt proper payment.
Not All Surgeries Merit Assistance
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.
Medicare specifies the procedures for which it allows additional payment for a surgical assistant, as identified by the “ASST SURG” column of the Medicare Physician Fee Schedule (MPFS) Relative Value File. If Medicare does not allow payment for an assistant at surgery, you cannot charge the patient, even if using an advanced beneficiary notice (ABN).
Indicators you might see in the ASST SURG column are:
2 – Medicare will pay for an assistant at surgery for that particular code.
0 – Medicare might pay for an assistant at surgery if documentation substantiates medical necessity.
1 – An assistant at surgery will not be paid.
9 – The concept of assisted surgery does not apply (i.e., Medicare will not pay for an assistant at surgery).
Table A (on the next page) shows several codes and their assistant-at-surgery indicators, which are from the most recent PFS Relative Value File.
Table A

CPT® Short Descriptor ASST SURG Indicator
32609 Thoracoscopy w/bx pleura


48500 Surgery of pancreatic cyst


55000 Drainage of hydrocele


65760 Revision of cornea


Resource: You may download the PFS Relative Value File free from the Centers for Medicare & Medicaid Services (CMS) website. All files are dated. Be sure to choose the most recent file, and check back quarterly for updates.
Medicare has established straightforward criteria to determine which codes are eligible for assistant-at-surgery reimbursement. Per the Medicare Claims Processing Manual, chapter 12, section 20.4.3, “Contractors 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.”
Third-party payers designate their own guidelines, or may stipulate limitations on assistants at surgery by contract. The best bet with these payers is to seek pre-authorization to ensure an assistant will be reimbursed for his or her effort in the operating room.
Documentation Must Support Medical Necessity
Documentation must establish medical necessity for all cases when a surgical assistant is used. Although a payer might not request documentation when a claim is filed, and might choose to pay a claim without review, you shouldn’t file a claim without documentation to support it. An operative note detailing the need for services rendered is not just a coding and reimbursement requirement, but also a compliance and ethical requirement.
The surgeon should specify in the body of the operative report what the assistant actually did. It’s insufficient to simply list the assistant’s name. The surgeon should clearly explain in the “indications” paragraph of the note why an assistant was necessary, and that he or she was involved in the actual performance of the covered surgical procedure, and not simply there to perform other ancillary services.
Coders should inform physicians of the documentation requirements for reporting assistant-at-surgery services. It’s not always easy communicating with physicians, but the alternative is lost reimbursement, which can occur again and again if not corrected.
Remember: When the surgeon signs an operative report, it becomes a legal document that cannot be altered. If necessary, however, the surgeon may dictate an addendum to his or her documentation, and the claim may be resubmitted.
Provider Type and Extent of Assistance Determines Modifier
You’ve determined the payer allows reimbursement for an assistant at surgery, and you’ve verified documentation establishes medical necessity for the same. The next factor to consider when preparing the claim is proper reporting. With three CPT® modifiers and a HCPCS Level II modifier to describe various assistant-at-surgery scenarios, this is where the real fun begins for most coders.
The first step is to know your payer. The instructions and examples below are based on national Medicare guidelines. For third-party payers, you may use the advice below as a general guideline, but be sure to check your contracts or inquire with the individual payer to determine which modifier you should use in a particular situation.
Modifier 80 Assistant surgeon: Modifier 80 identifies services provided by a surgical assistant who is a medical doctor. Append this modifier only to the primary surgical service.
For example, an assistant surgeon frequently is used during arthrodesis surgery. The assistant helps to hold the vertebrae in place and assist in harvesting and placing the bone graft. In such a case, the primary surgeon might report 22610 Arthrodesis, posterior or posterolateral technique, single level; thoracic (with or without transverse technique), while the assistant surgeon would report 22610-80.
For assistant-at-surgery services performed by physicians, the fee schedule amount equals 16 percent of the amount otherwise applicable for the surgical payment.
Modifier 82 Assistant surgeon (when qualified resident surgeon not available): Append modifier 82 only in a teaching hospital setting and only if a qualified resident is not available to assist during surgery.
Per the Claims Processing Manual (chapter 12, section 100.1.7), Medicare does not pay for assistant-at-surgery services furnished in a teaching hospital that has a training program related to the medical specialty required for the surgical procedure, unless:

  • A qualified resident surgeon was not available.
  • Medical staff determined exceptional circumstances justified the services of an assistant at surgery, even though a qualified resident was available.
  • The primary surgeon has an across-the-board policy of never involving residents in the preoperative, operative, or postoperative care of his or her patients.

For example, a lung hernia through the chest wall needs immediate repair in a teaching hospital setting. The residents on call are assisting in another procedure, and a second thoracic surgeon assists the primary surgeon. In this case, the primary surgeon reports 32800 Repair lung hernia through chest wall, while the assistant surgeon reports 32800-82.
The assistant surgeon should document clearly in the operative report why a resident was not involved in the case. You may also use Box 19 on the CMS-1500 form to indicate why a resident did not provide assistance during the surgery.
Modifier AS Physician assistant, nurse practitioner, or clinical nurse specialist services for assistant at surgery: Use this modifier for Medicare if a physician assistant (PA), nurse practitioner (NP), or clinical nurse specialist—rather than a medical doctor or doctor of osteopathic medicine—assists during a surgical procedure. Section 110.2 of the Claims Processing Manual stipulates:
“… when a PA actively assists a physician in performing a surgical procedure and furnishes more than just ancillary services, the PA’s services are eligible for payment as assistant-at-surgery services … the actual payment amount that PAs receive for assistant-at-surgery services is 13.6 percent of the amount paid to physicians…. The AS modifier must be reported on the claim form when billing PA assistant-at-surgery services.”
Modifier 81 Minimum assistant at surgery: Modifier 81 describes minimal assistance during surgery by another physician. Payers may also allow modifier 81 to report a second physician in the operating room for a small, selective portion of a particular procedure (such as opening and closure only).
Medicare payers generally do not recognize modifier 81 for payment, and CMS does not include modifier 81 in the PFS Relative Value File. Whereas you should never use modifier 81 to indicate a non-physician (e.g., PA or NP) assisting at surgery for Medicare, some third-party payers (who don’t recognize modifier AS) may accept modifier 81 for this purpose.

Marilyn Holley, CPC, CPC-I, RHIT, CHISP, is AAPC’s director of education.

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11 Responses to “Prompt Proper Assistant-at-surgery Payment”

  1. Tammy Martinson, CPC, CPMA, CEMC says:

    Thank you Marilyn for a great article. Can this information be found on the Medicare website, stating that the information should be in the report? My employer wants it black and white from another source.

  2. Christina Hunter, CPC, COSC says:

    Hi Tammy,
    Try a specialty society that your physician belongs to we are an orthopedic practice so when my employer wanted it in black and white I was able to find an AAOS article supporting the requirement for documentation of an assistant at surgery.

  3. Claudia Yoakum-Watson says:

    Could you please share where it is documented that Modifier 80 is only for assistants who are medical doctors? Thanks.

  4. Allen Johnson says:

    Hi , my name is Allen Johnson and I am a certified inpatient & outpatient medical biller, and I bill for several Assistant Surgeons who are out of network. I am having a hard time getting the insurance carriers to pay for my Assistant Surgeons. Is there a document that I can send to the Insurance along with the operative report
    showing medical necessity? If so would you Please tell me where to go get that document? Thank You.

  5. Cindy Lamoureux says:

    Hi I would like some feedback as far as billing for an assistant surgeon please. I have taken several coding course and attended many seminars for coding and have been told to bill out the primary surgeons fee with modifier 80 and let each payer make the adjustment depending on what that payer allows. Does anyone out there have any input on this.

  6. Cathey P says:

    Allen: Can you tell me if a physician assists another doctor (outside of the practice), are there guidelines that state the assistant surgeon must bill the same fee as the primary surgeon or can we just use our UCR?

  7. Olga McIntosh says:

    Hi, I am inquiring about the requirement for “resident assist at surgery ” does the attending have to indicate in op-note what the resident did, or the statement “I was present and scrubbed for all critical portions of this case and immediately available thereafter”?.
    thanks in advance.

  8. Callie Sowder says:

    I would also like something from CMS stating the requirement that it show in the note what the assistant surgeon performed?

  9. Karen Lusk says:

    I would like to know what determines a “qualified” resident? I have been advised of several different things as far as the resident is qualified to assist starting their first year, and then I have been told that the resident is not “qualified” until their 4th or 5th year of residency. So what is considered a “qualified resident”? And is there documentation anywhere to support this information?

  10. Sharon Harris says:

    I believe the. Guidelines state: if it is not documented it did not happen! How much more black and white can you get?

  11. Cathy says:

    I have a provider that wants to bill the PA along with the Specialty surgeon who assisted. My understanding that only one assist was allowed to be billed when the documentation does not specifically state what the assist has performed . Please advise Thank you