Neurosurgery Coding Alert

Faced with the choice of three CPT modifiers, plus a HCPCS modifier -- all with similar definitions -- even an experienced coder can easily become overwhelmed when trying to report an assistant-at-surgery claim. Our experts offer five steps to reduce the confusion and append the correct modifier, every time.

As a first step, you must determine if the code for which you wish to report an assistant at surgery is eligible for assistant-at-surgery payment, says Suzan Berman-Hvizdash, CPC, CPC-E/M, CPC-EDS, physician educator for the University of Pittsburgh and past member of the American Academy of Professional Coders National Advisory Board.

Payers will not reimburse for assistants at surgery in all cases, regardless of the modifiers you append to the claim. "Many carriers create their own rules that determine which practitioners can bill as assistant surgeons," says Barbara J. Cobuzzi, MBA, CPC-OTO, CPC-H, CPC-P, CPC-I, CHCC, consulting director of education for The Coding Institute in Naples, Fla.

For Medicare, services rendered by an assistant at surgery are eligible for reimbursement only when national claims data indicate the procedure necessitated an assistant in at least 5 percent of the claims based on a national average, according to the Internet Only Manual, Chapter 20, Section 20.4.3.

The easiest way to check if a code is eligible for assistant-at-surgery payment is to check the "ASST SURG" column of the Medicare Physician Fee Schedule Relative Value File, Cobuzzi says.

If you find a "2" in this column for the code you wish to report, Medicare will reimburse for an assistant at surgery. Likewise, if you find a "0," Medicare will allow payment for an assistant at surgery as long as you submit supporting documentation to establish medical necessity.

In contrast, a "1" in the "ASST SURG" column tells you that Medicare will never pay for an assistant at surgery, while a "9" indicates that the concept of assisted surgery does not apply.

Resource: You can download the Physician Fee Schedule Relative Value File from the Medicare Web site, www.cms.hhs.gov. From the home page, search for "PFS Relative Value File," and select the first search result. Be sure to download the most recent (2008) file available.

According to Medicare guidelines set forth in the Internet Only Manual (chapter 20, section 20.4.3), "an assistant at surgery must actively assist when a physician performs a Medicare-covered surgical procedure. This necessarily entails that the assistant be involved in the actual performance of the procedure, not simply in other, ancillary services."

The IOM continues, "Since an assistant would, thus, be occupied during the surgical procedure, the assistant would not be available to perform (and thus, could not bill for) another surgical procedure during the same time period."

You should append modifier 80 (Assistant surgeon) to describe the presence of a second physician in the operating room who acts as an "extra pair of hands" to assist the primary surgeon. You would also select this modifier to describe an assistant surgeon in a "teaching" setting where the primary surgeon never uses residents in his cases, Berman-Hvizdash adds.

Important: Do not confuse modifier 80 with modifier 62 (Two surgeons), which describes two physicians acting as co-surgeons.

Chapter 20 of IOM, section 40.8, specifies that each co-surgeon serves as the primary surgeon during some part of the operation and that each performs a distinct portion of a single reportable procedure. Although the surgeons operate on the same patient during the same operative session, they in fact work independently of one another. A single surgeon can serve as both a co-surgeon and an assistant surgeon during different portions of the same operative session.

Example: A trauma patient with shattered thoracic vertebrae undergoes surgery for spinal reconstruction, resulting in the following procedures:

In this case, the complete reconstruction requires two surgeons. Surgeon A does the vertebral resection, while surgeon B decompresses the spinal cord. Surgeon A performs the arthrodesis and, with surgeon B's assistance, places the instrumentation. Coding should appear as follows:

Because each surgeon performs a distinct portion of the vertebral corpectomy (the resection and decompression, respectively), each surgeon should report 63087 and 63088 with modifier 62 appended. Surgeon A reports 22556 and 22585 x 2 for the arthrodesis, plus 22846 for instru-mentation. Because Surgeon B acted as an assistant (rather than a co-surgeon) during instrumentation placement, he reports 22846 also, but with modifier 80 appended.

If a nonphysician practitioner (NPP) serves as an assistant surgeon, you must use modifier AS (Physician assistant, nurse practitioner, or clinical nurse specialist services for assistant at surgery) for Medicare payers.

Specifically, Medicare payers will typically reimburse for the services of a clinical nurse specialist (CNS), physician assistant (PA) and nurse practitioner (NP) as assistants at surgery. Medicare will not reimburse for surgical assistants such as registered nurse first assists, orthopedic physician assistants, licensed practical nurses, and certified surgical technologists.

Important: For Medicare, the PA assisting at surgery must have a Medicare (or Medicaid) provider number to bill for assistant-at-surgery services.

Example: A PA assists the surgeon during neuro-endoscopy with dissection of adhesions and placement of a ventricular catheter (62161, Neuroendoscopy, intracranial; with dissection of adhesions, fenestration of septum pellucidum or intraventricular cysts [including placement, replacement, or removal of ventricular catheter]). The physician fee schedule database assigns a "2" to the ASST SURG column for 62161, which means you may report an assistant at surgery for this procedure.

In this case, the surgeon would report 62161, and the PA will report 62161-AS.

You should apply modifier 82 (Assistant surgeon [when qualified resident surgeon not available]) only in a teaching hospital setting, and then only if a qualified resident is not available to assist, Berman-Hvizdash says.

In general, Medicare will not make separate payment for first assisting when the service is provided in a teaching hospital that has a training program related to the particular surgical procedure and a qualified resident is available. CMS will not allow additional payment because Medicare has already reimbursed the hospital for such services via its residence funding.

But: If the teaching hospital has no qualified resident available or no teaching program related to the particular medical specialty required for the procedure, or if the primary surgeon has an across-the-board policy of not using residents, Medicare will pay an assistant surgeon.

Tip: When reporting modifier 82, you should be sure that the surgeon provides a clear note in the body of the op report as to why a resident was not involved in the case (for example, due to case complexity; there weren't enough residents; the primary surgeon never works with residents, etc.).

Berman-Hvizdash further recommends that the surgeon include a statement, such as the following, in his documentation: "I understand that -1842(b)(7)(D) of the Act generally prohibits Medicare physician fee schedule payment for the services of assistants at surgery in teaching hospitals when qualified residents are available to furnish such services. I certify that the services for which payment is claimed were medically necessary and that no qualified resident was available to perform the services. I further understand that these services are subject to post-payment review by the Medicare carrier."

Consult your payers- specific guidelines prior to reporting modifier 81 (Minimum assistant surgeon). Get payer instructions in writing, and follow them to the letter.

Modifier 81 specifies "minimum" assistant surgeon, but neither CPT nor CMS provides definitive guidelines to help physicians and coders distinguish a minimum assistant from a "regular" assistant as described by modifier 80. This absence of clarity causes payers to interpret modifier 81 differently.

Some payers will allow modifier 81 for midlevel assistants such as PAs, but Medicare will allow only modifier AS for these providers. Other payers may 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).