Pyogenic (bacterial) infection of the intervertebral disc located at the sacral or sacrococcygeal spinal level, classified under other inflammatory spondylopathies.

Documentation tips

What should appear in the chart to support M46.38.

Source · Editorial brief grounded in 3 cited references ↓

• Explicitly state 'sacral' or 'sacrococcygeal' region in the assessment — vague 'lower spine' language forces the coder to default to an unspecified level.
• Record the causative organism by name or by culture result so the required B95–B97 secondary code can be assigned accurately.
• Document imaging findings that support infection: MRI signal changes, end-plate erosion, disc space narrowing, or paraspinal soft-tissue involvement.
• Note pertinent risk factors (IV drug use, recent spinal procedure, immunosuppression, diabetes) as separately coded comorbidities — they support medical necessity for advanced imaging and inpatient admission.
• If the infection spans more than one spinal region, document each affected level clearly so the correct multi-site or individual region codes can be assigned.

Related CPT procedures

Procedure codes commonly billed with M46.38. 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 M46.38 and adjacent codes.

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

• Assigning M46.38 without a companion B95–B97 organism code violates the mandatory 'Use additional code' instruction at the M46.3 parent level — expect a claim edit or audit flag.
• Using M46.38 for non-pyogenic disc infections (tuberculous, fungal) is incorrect; those infections have distinct codes (e.g., A18.01 for tuberculosis of spine).
• Defaulting to M46.40 (discitis, unspecified, site unspecified) when the record clearly documents a pyogenic etiology and sacral location — this undercodes a confirmed, site-specific diagnosis.
• Confusing the sacral region (M46.38) with the lumbosacral region (M46.37); verify the documented level against imaging before finalizing the code.

Clinical context

Source · Editorial summary grounded in 3 cited references ↓

Sibling codes

Other billable codes under M46.3 (laterality / anatomic variants).