When acting as co-surgeons, the two surgeons operate on the same patient but, in fact, work independently of one another. In other words, each surgeon performs a distinct portion of a single reportable procedure.
By contrast, you should use modifier -80 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. For example, an orthopedic surgeon and a neurosurgeon may work together during placement of spinal instrumentation (that is, 22842, Posterior segmental instrumentation [e.g., pedicle fixation, dual rods with multiple hooks and sublaminar wires]; 3 to 6 vertebral segments). During the procedure the orthopedic surgeon assists the neurosurgeon but does not perform any portion of the procedure himself.
Note: Most payers reimburse assistant surgeons at 16 percent of the regular fee schedule amount.
Remember: If two surgeons of different specialties work together during the same operative session but each performs a distinct, separately identifiable procedure, you would consider this "sequential surgery," and each surgeon may bill independently with no modifiers appended.