AAOS Bulletin - August, 2006

Coding when there is more than one surgeon

Tips to avoid spine coding snafus

By Mary LeGrand, RN, MA, CCS-P, CPC

Coding spine cases can sometimes seem almost as challenging as performing the surgery. If there are multiple surgeons, the role of each one must be clearly identified and the procedures reported by each must be well documented.

Payers are denying cosurgeon and assistant surgeon services on spine cases more frequently. As billing staff attempt to appeal effectively, they often find that the procedural documentation and work performed by each physician or physician assistant (PA) are not clear. The following tips may help simplify spine coding.

Surgeon roles

Typically, three key clinicians will bill for spine surgery services:

• Primary surgeon

• Cosurgeon

• Assistant surgeon (a medical or osteopathic physician) or an assistant at surgery such as a physician’s assistant (PA), a nurse practitioner (NP) or a clinical nurse specialist (CNS).

The operative notes should be very clear about the status of the second surgeon. They should specify whether the second surgeon is the co-surgeon, an assistant or a non-physician provider.


Cosurgery means that two surgeons are performing distinct separate parts of the same procedure. This most frequently occurs when one surgeon performs the approach and the other surgeon performs the definitive procedure. For both surgeons to receive appropriate reimbursement, they must not be assisting each other, but performing distinct and separate parts of the same procedure.

For example, an otolaryngologist (ENT surgeon) may do the approach for an anterior cervical fusion. Both surgeons would list CPT code 22554-62 when submitting the claim. Each surgeon would dictate personal operative notes describing the distinct part of the procedure performed. Dr. Otolaryngology would dictate the approach and then turn the dictation over to Dr. Spine. Dr. Spine would begin his operative note stating the patient was positioned and the approach was performed and dictated by Dr. Otolaryngology. Dr. Spine typically states, “After Dr. Otolaryngology made the approach to the spine, we entered the case. . . ”

Dr. Spine would not dictate the work performed by Dr. Otolaryngology and Dr. Otolaryngology would not dictate the part of the procedure performed by Dr. Spine. Both surgeons would report the appropriate CPT code with a -62 modifier on the primary procedure. Subsequent procedures would be reported with the assistant surgeon modifier if one of the surgeons remained involved and assisted on the case.

Following these steps will result in Medicare reimbursement to both surgeons of 62.5 percent of the allowable amount for the procedures they report as cosurgeons. When there are cosurgeons, Medicare increases the normal allowable reimbursement (payable if only one surgeon performs the case) by 25 percent, then splits the results equally between the two surgeons, resulting in the 62.5 percent payment.

The cosurgeon modifier should be appended to only one primary procedure code and its associated add-on codes. If the second surgeon continues to assist on the case, he or she becomes the assistant surgeon. The surgeons may not append the cosurgery modifier to instrumentation or bone graft codes.

Assistant surgeon or assistant at surgery

When there is an assistant surgeon or an assistant at surgery, the surgeon of record is listed as the primary surgeon. The surgeon of record is responsible for identifying the presence of the assistant surgeon or assistant at surgery and the work performed. In this situation, the assistant surgeon or assistant at surgery does not dictate an operative note. An MD or DO serving as the assistant surgeon will report the CPT codes for those procedures.

The primary surgeon would report the procedures without a modifier and at their full fee. The assistant would append the appropriate assistant modifiers and at a reduced fee (generally some percent above the payer’s allowable amount). The following modifiers should be used:

• Modifier 80: Assistant surgeon (MD or DO) who assisted on the majority of the case

• Modifier 81: Assistant surgeon (MD or DO) who assisted on less than the majority of the case

• Modifier 82: Assistant surgeon (MD or DO) in an academic institution where no qualified resident is available-AS Modifier: Medicare modifier for a PA, NP or CNS who is an assistant at surgery

Medicare reimburses the assistant surgeon (MD or DO) 16 percent of the allowable amount for primary procedures and appends the appropriate multiple procedure payment formula for subsequent procedures. Medicare reimburses the assistant at surgery (PA, NP or CNS) 13.6 percent of the allowable amount for primary procedures and applies the appropriate multiple procedure payment formula for subsequent procedures. Private payers may use different modifiers to indicate a PA, NP or CNS assistant at surgery; be sure you know how each of your carriers wants this coded.

Cosurgeon example

An orthopaedic surgeon prepares a patient for an anterior lumbar interbody fusion at L3-L4 and L4-L5. He plans to place cages at both intervertebral spaces. A general surgeon dictates the approach, listing himself as surgeon and the orthopaedist as cosurgeon. In his operative note, the orthopaedist lists himself as the surgeon and lists the general surgeon as the cosurgeon. The orthopaedist dictates the definitive procedure after the approach. The orthopaedic surgeon’s claim submission would look like this:


(Orthopaedic surgeon)


(General surgeon)

22558-62 (anterior fusion)


22585-62 (additional spinal fusion)


22851 (anterior instrumentation)


22851-59 (removal of spine fixation device)


Assistant surgeon example

A spine surgeon is operating on a patient with spinal stenosis and disc disease. The operative plan includes a posterior lumbar interbody fusion at L3-L4 and L4-L5 as well as a posterolateral fusion from L3-L5. Pedicle screws will be placed bilaterally at L3, L4 and L5, with structural allografts at L3-L4 and L4-L5. An autograft will be harvested from the patient’s iliac crest for the posterolateral fusion.

Primary surgeon

Assistant surgeon (MD or DO)

22612 (lumbar spine fusion)


22614 (spine fusion, extra segment)


22630-51 (arthrodesis by posterior interbody technique )

22630-80, 51

22632 (additional interspace)


22842 (segmental instrumentation)


20937 (bone graft)


20931 (spinal bone allograft)


The surgeon’s partner is present for the entire case and assists with the approach, definitive surgery and insertion of spinal instrumentation, but not with placement of the allografts. The claim submission would include the following codes

If the primary surgeon had been working with an assistant at surgery (PA, NP or CNS), the claim submission would include the same codes, but with the –AS modifier, as shown below.

Primary surgeon

Assistant at surgery per Medicare

22612 (lumbar spine fusion)


22614 (spine fusion, extra segment)


22630-51 (arthrodesis by posterior interbody technique)

22630-AS, 51

22632 (additional interspace)


22842 (segmental instrumentation)


20937 (bone graft, iliac crest)


20931 (spinal bone allograft)



It is critical to appropriately document the role of each physician, as well as the medical necessity of the second surgeon/assistant. When two surgeons are reporting services as cosurgeons, two distinct operative notes are required. The operative notes should not overlap because this negates the concept of cosurgery and will drive the use of the appropriate assistant versus cosurgeon modifiers.

Do not append an assistant surgeon or assistant at surgery modifier if the physician does not document the role associated with the procedure. For example, an assistant is usually not required for the bone grafting procedures because only one surgeon inlays the allograft or autograft. Finally, watch your reimbursements closely and appeal inappropriately denied services!

Mary LeGrand, RN, MA, CCS-P, CPC, is a consultant with KarenZupko & Associates, Inc.

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