CMM-609 Lumbar Fusion (Arthrodesis)

Covered: Lumbar fusion and associated osteotomies are medically necessary for defined indications such as actual or anticipated instability (e.g., progressive spondylolisthesis, facet/pars disruption, post‑decompression instability), adult degenerative spinal deformity meeting specific radiographic thresholds, select disc herniations (e.g., extraforaminal L5‑S1 or foraminal herniation requiring facet resection), pediatric scoliosis meeting curve criteria, failed arthroplasty/adjacent‑segment disease (prior fusion ≥6 months), symptomatic pseudoarthrosis, and specified osteotomies when strict angular/segmental correction criteria are met; excluded are fusion for isolated disc herniation without instability, multi‑level DDD without instability, neurocompressive or facet‑only pathology, initial discectomy/laminectomy without instability, and listed experimental techniques (e.g., AxiaLIF, endoscopic/percutaneous fusions). Key requirements: case‑by‑case medical necessity with specified conservative‑treatment prerequisites where applicable, required imaging/metric documentation, documentation of nicotine‑free status (never‑smoker or cotinine ≤10 ng/mL ≥6 weeks preop) except in urgent/emergent cases, operative documentation if intraoperative instability is claimed, and procedure limits (e.g., PCO ≤4 osteotomies per correction).