Otolaryngology Coding Alert

As a coder specializing in otolaryngology, it’s crucial to understand the significance of modifiers in medical claims. Misuse or incorrect application of modifiers can lead to claim denials.

Specifically, if someone of another specialty serves as an assistant surgeon during a procedure, it’s important to know the appropriate time and method to append certain modifiers.

Check out this guide to learn how to append assistant at surgery modifiers.

Understand When an Assistant Surgeon Is Necessary

According to Medicare guidelines, an assistant at surgery is “a physician who actively assists the physician in charge of a case in performing a surgical procedure.” A primary surgeon may require an assistant surgeon during a procedure for several reasons, including the complexity of the procedure or a patient having multiple comorbidities that could complicate the treatment. In those cases, the assistant surgeon works under the primary surgeon’s direct supervision.

The operative note should list the primary surgeon and the assistant surgeon. Plus, the documentation needs to include the assistant surgeon’s role during the procedure.

Your coding will depend on which surgeon you’re reporting on the claim. If you’re reporting the procedure for the primary surgeon, you’ll assign the correct procedure code without an assistant surgeon modifier. However, you’ll append an applicable modifier to the same procedure code when you’re billing for an assistant surgeon.

Master the Assistant Surgeon Modifiers

The CPT^® code set features three assistant-surgeon modifiers:

• 80 (Assistant surgeon)
• 81 (Minimum assistant surgeon)
• 82 (Assistant surgeon (when qualified resident surgeon not available))

Choosing between modifiers 80 and 81 comes down to the assistant surgeon’s involvement in the surgery. You’ll append modifier 80 if they participate in the entire procedure, but you’ll use modifier 81 when the assistant surgeon assists with a portion of the operation.

Payment is not allowed for assistants at a surgery when it is furnished in a teaching hospital that has a training program related to the medical specialty required for the surgical procedure and has a qualified resident available to perform the service. If the assistant surgeon has to perform the entire procedure, then you’ll append modifier 82 to the applicable CPT^® code. The Centers for Medicare & Medicaid Services (CMS) outlines several scenarios in the Medicare Claims Processing Manual where the qualified resident may be unavailable and when appending modifier 82 would apply.

They include situations where:

• A resident was working on other activities (i.e., partici­pating in grand rounds), rendering them unavailable.
• The resident doesn’t possess the necessary skills to assist with a complex surgery.
• The residency program has a limited number of residents.

The patient requires urgent treatment due to a life-threatening condition, multiple traumatic injuries, or another emergency situation.

Analyze These Modifier AS Uses

Medicare will pay for an assistant surgeon when an assistant is authorized for the procedure. However, the provider performing the assistance must be a physician, physician assistant (PA), nurse practitioner (NP), or clinical nurse specialist (CNS).

In procedures where a PA, NP, or CNS assists during the surgery, you’ll append HCPCS Level II modifier AS (Physician assistant, nurse practitioner, or clinical nurse specialist services for assistant at surgery) to the surgery code.

When the healthcare professionals listed above act as surgery assistants, make sure you do not include modifier 80, too.

Why? According to the Medicare Claims Processing Manual, only modifier AS should be reported on the claim:

• “When billing PA assistant-at-surgery services” (Section 110.2)
• “When an NP or CNS bills assistant-at-surgery services” (Section 120.1)

As always, you should review your individual payer preferences to check how they want billing for surgical assistants. Many commercial payers follow Medicare’s billing rules, but not all of them do. Some payers may want modifier AS, while others may not recognize it entirely.

Find Out if the Procedure Allows Assistant Surgeon Billing

Billing for an assistant at surgery for Medicare reimbursement requires more than just appending the correct modifier. The Medicare Physician Fee Schedule (MPFS) features an assistant surgeon (Asst Surg) column that indicates if a procedure allows an assistant. The indicator listed in the column will let you know the reimbursement rules for the procedure:

• 0: Medicare will allow payment for assistant at surgery only if there is documentation supporting medical necessity.
• 1: Medicare will not pay for assistant at surgery. Do not append modifier 80, 81, 82, or AS to these codes.
• 2: Medicare will allow payment for assistant at surgery. Append modifier 80, 81, 82, or AS to show that an assistant surgeon was involved in the encounter.
• 9: Assisted surgery concept doesn’t apply.

Payers won’t reimburse for assistants at surgery in every surgical case, even if you append 80, 81, 82, or AS to the claim. Medicare guidelines state that surgery services rendered by an assistant are eligible for reimbursement only when the procedure would require an assistant in 5 percent or more of claims submitted nationally. “A good guideline is that X, 0-, and 10-day global period procedures do not allow an assistant while 90-day procedures typically do. Always use the Medicare Physician Fee Schedule Database Lookup Tool to be sure,” says Terri Brame Joy, MBA, CPC, COC, CGSC, CPC-I, product manager, MRO, in Philadelphia.

“However, in otolaryngology, functional endoscopic sinus surgeries (FESS) carry zero global days, yet can be fairly complex and might require an assistant surgeon. So, do not assume that just because a CPT^® code is a minor procedure, carrying a 0- or 10-day global period, it does not support an assistant surgeon. Also, procedures that do not support an assistant surgeon may have circumstances, such as extensive hemorrhage, that make the need for an assistant surgeon necessary,” says Barbara Cobuzzi MBA, CPC, COC, CPC-P, CPC-I, CENTC, CPCO, CMCS, of CRN Healthcare Solutions of Tinton Falls, New Jersey.

Tip: Make sure the complications causing the primary surgeon to need the assistant surgeon are sufficiently documented in the operative note — in the body and in the findings paragraph — so the billing staff can appeal and support the medical necessity of that assistant surgeon.

“For example, basic FESS surgeries, ethmoidectomy, maxillary antrostomy, and frontal sinusotomy do not allow for an assistant surgeon. A sphenoidotomy does allow for an assistant surgeon when supported, which means the documentation has to show why the assistant surgeon was needed. But if a patient who has an ethmoidectomy, maxillary antrostomy, and/ or frontal sinusotomy hemorrhages significantly while the hyperplastic tissue is being removed, causing the surgeon to need assistance in getting all the hyperplastic tissue removed as quickly as possible to minimize the hemorrhage and blood loss for the patient, the documentation will make the difference as to whether the practice will be able to get that assistant surgeon compensated,” Cobuzzi notes.

Scenario: An ENT surgeon uses an endoscope to examine the nasal cavity and sinuses and ties off the sphenopalatine artery (SPA) to control epistaxis (nosebleed). A PA acts as an assistant at the surgery.

For this scenario, you’ll assign 31241 (Nasal/sinus endoscopy, surgical; with ligation of sphenopalatine artery) to report the procedure. Under the Asst Surg column of the MPFS, 31241 carries a “2,” which means Medicare will provide reimbursement for an assistant surgeon when supported. So, when you are billing for the assistant surgeon’s services and appending the modifier AS to the code, the conditions making the need for the assistant surgeon must be clearly outlined in the operative note.

“I recommend summarizing the conditions calling for that assistant surgeon in the findings paragraph at the beginning of the operative note and then providing details of the complexities encountered creating the need for an assistant in the body of the operative note in order to support the request for payment for the assistant surgeon,” Cobuzzi advises.