Question: Should I report four units of arthrodesis when the surgeon fuses vertebrae L2 through L5 posteriorly? Massachusetts Subscriber Answer: No. You should report 22612 (Arthrodesis, posterior or posterolateral technique, single level; lumbar [with or without lateral transverse technique]) along with two units of +22614 (... each additional vertebral segment [list separately in addition to code for primary procedure]). Key: This procedure involves four vertebrae (L2, L3, L4 and L5), but the surgeon only fuses three separate levels or interspaces (L2-L3, L3-L4 and L4-L5). Arthrodesis implies a fusion of a motion segment, which includes two adjacent vertebrae and the intercalary disc and/or facet joints (in other words, two segments and the interspace/joint between them). Helpful: Additionally, the descriptors for 22600-22614 specifically refer to spinal "levels" -- not vertebrae. -- Reader Questions and You Be the Coder were reviewed by Heidi Stout, CPC, CCS-P, director of orthopedic coding services at The Coding Network LLC; and Bill Mallon, MD, orthopedic surgeon and medical director at Triangle Orthopaedic Associates in Durham, N.C.