Question: Is it appropriate to report laminectomy codes 63045-63048 per segment or per interspace? CPT says "per segment," but my physician disagrees. For example, how should I report lumbar facetectomy/ foraminotomy L3-L5? Pennsylvania Subscriber Answer: CPT very specifically defines 63045-63048 as applicable per vertebral segment, and further defines a segment as "the basic constituent part into which the spine may be divided," consisting of "a single complete vertebral bone with its associated articular processes and laminae." In contrast, CPT defines an interspace as "the non-bony compartment between two adjacent vertebral bodies, which contains the intervertebral disk, and includes the nucleus pulposus, annulus fibrosus and two cartilaginous endplates." Note: Some experts have argued that 63045-63048 should apply per interspace because whatever the surgeon does to the inferior portion of one vertebra he or she also does to the superior portion of the vertebra across that interspace. This is not always the case, however, and CPT has precisely and consistently argued that the codes are to be reported per segment. In your example, the physician attends to three segments (L3, L4 and L5). Therefore, you should report 63047 (Laminectomy, facetectomy and foraminotomy [unilateral or bilateral with decompression of spinal cord, cauda equina and/or nerve root(s) (e.g., spinal or lateral recess stenosis)], single vertebral segment; lumbar) and +63048 (... each additional segment, cervical, thoracic, or lumbar [list separately in addition to code for primary procedure]) x 2. Some payers may require you to append modifier -59 (Distinct procedural service) to the second and subsequent units of 63048, but this is not a CPT requirement (see "Insurer Has Final Say on Modifiers," in article 5).