Question: Does 63056 represent a bilateral or a unilateral procedure? Washington Subscriber Answer: Medicare policy does not allow you to use modifier -50 (Bilateral procedure) with 63056 (Transpedicular approach with decompression of spinal cord, equina and/or nerve root[s] [e.g., herniated intervertebral disk, single segment; lumbar [including transfacet, or lateral extraforaminal approach] [e.g., far lateral herniated intervertebral disk]). CPT offers no specific guidance on whether the code applies to a bilateral or unilateral procedure. But in most cases, surgeons will perform the procedure unilaterally. If the surgeon must perform the procedure on both sides of the spine, your best coding choice may be to report 63056-LT (Left side) and 63056-RT (Right side) and provide documentation outlining the extensive nature of the procedure. Coders have had success with this method, although at times you may have to appeal a rejection.