Spinal fusion is the most common surgical procedure in spinal surgery,and because of the diversity of the surgical techniques,the ICD-9-CM-3 coding is different.This article analyzes the meanings of the different subheadings under 81.0 in the ICD-9-CM-3 classification system,and combines clinical actual application surgical cases to elucidate the coding strategy for spinal fusion.The main surgical code is determined based on the entry route and the specific fusion site of the surgery.Cranio-cervical,cervical,and thoraco-cervical spinal fusion is classified under 81.01 to 81.03,thoracic and thoraco-lumbar spinal fusion is classified under 81.04 to 81.05,lumbar and lumbosacral spinal fusion is classified under 81.06 to 81.08,and try to avoid 81.00(spinal fusion,not otherwise specified),and the total number of fused vertebrae must be coded separately with codes 81.62 to 81.64.Based on the specific content of the surgical record,additional codes are selected.Attention should be paid to the codes that should be omitted in a full understanding of the coding rules,such as hone grafting surgery 78.0,vertebral internal fixation surgery(at the same level as the fusion)78.59,and the collection of bone grafting by removing autologous fragmented bone during the surgery.Only by actively participating in coding training,systematically learning coding principles,and continuously improving their understanding of medical knowledge,can coders correctly code.