Bacterial or hematogenous infection of one or more vertebral bodies localized to the thoracic spine (T1–T12), classified under other inflammatory spondylopathies.

Documentation tips

What should appear in the chart to support M46.24.

Source · Editorial brief grounded in 5 cited references ↓

• Specify the thoracic level (e.g., T6–T7) in the note — 'thoracic region' alone satisfies the code, but level-specific documentation supports clinical validation during audit.
• Add the causative organism code (B95–B97 for bacterial/viral; A18.01 for tuberculous vertebral osteomyelitis) as an additional diagnosis — ICD-10-CM instructs 'use additional code' at the M46.2 category level.
• Document MRI findings explicitly: T1 hypointensity, T2/STIR hyperintensity, endplate erosion, and/or paraspinal or epidural abscess extension — these findings are the primary imaging validators for vertebral osteomyelitis.
• Record lab markers: ESR, CRP, WBC, blood culture results, and bone biopsy or intraoperative culture results when available, as payers and RAC auditors look for objective evidence supporting this diagnosis.
• If disc involvement is also present, assign M46.34 (pyogenic infection of intervertebral disc, thoracic region) as an additional or primary code alongside M46.24 — do not rely on M46.24 alone when discitis is documented.
• Note chronicity and treatment course (IV antibiotics, duration, surgical debridement history) to support medical necessity for imaging, prolonged antibiotic therapy, and surgical procedures linked to this diagnosis.

Related CPT procedures

Procedure codes commonly billed with M46.24. Linking the right diagnosis to the right procedure is what establishes medical necessity.

Source · CMS LCDs · AAOS specialty guidance · claims-pattern analysis

Common coding pitfalls

The recurring mistakes coders make with M46.24 and adjacent codes.

Source · Editorial brief grounded in CDC ICD-10-CM tabular guidance, AAOS coding references, and cited references ↓

• Omitting the causative organism code: M46.24 requires a supplemental B95–B97 (or A-code for TB) code to satisfy the 'use additional code' instruction — claims submitted with M46.24 alone are incomplete and may be down-coded or denied.
• Confusing vertebral osteomyelitis with disc space infection: M46.24 is for bone involvement of the vertebral body; M46.34 covers pyogenic infection of the intervertebral disc in the thoracic region. When both are documented, both codes are needed.
• Applying M46.24 when the infection spans multiple spinal regions: if the provider documents osteomyelitis crossing thoracic and lumbar levels, use M46.25 (thoracolumbar) or assign multiple codes per the documented extent — do not default to M46.24 for multi-region disease.
• Defaulting to M46.20 (site unspecified) when the thoracic region is documented: if the chart specifies thoracic involvement, M46.24 is required — using the unspecified code on a complete record is a specificity failure that can trigger a query or audit.
• Using M46.24 for tuberculous spondylitis (Pott's disease): tuberculous infection of thoracic vertebrae is classified to A18.01 (tuberculosis of spine), not M46.24 — misassignment understates the infectious etiology and may affect authorization.

Clinical context

Source · Editorial summary grounded in 5 cited references ↓

Sibling codes

Other billable codes under M46.2 (laterality / anatomic variants).