M99.71 identifies narrowing of the intervertebral foramina in the cervical spine caused by connective tissue overgrowth or disc pathology — a biomechanical lesion classification used when no more specific structural diagnosis applies.

Documentation tips

What should appear in the chart to support M99.71.

Source · Editorial brief grounded in 3 cited references ↓

• Document 'cervical' explicitly — the M99.7x family requires region specificity; 'neck' alone is insufficient to lock in the cervical qualifier.
• Record the anatomic structure affected: the intervertebral foramen (not the spinal canal) — this distinguishes M99.71 from M99.41 and M48.02.
• Note the causative mechanism: connective tissue hypertrophy, disc bulge, or combined — this supports the connective tissue and disc stenosis descriptor.
• Include imaging findings (MRI or CT) showing foraminal narrowing, specifying level(s) involved (e.g., C5-C6 foraminal stenosis).
• If a more specific structural diagnosis is supported by imaging (e.g., herniated nucleus pulposus with foraminal compression), code that condition instead and reserve M99.71 for true residual biomechanical classification.

Related CPT procedures

Procedure codes commonly billed with M99.71. 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 M99.71 and adjacent codes.

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

• Using M99.71 when a more specific disc or degenerative code (e.g., M50.12, M47.812) applies — the M99 category note prohibits this code when the condition is classifiable elsewhere.
• Confusing foraminal stenosis (M99.71) with neural canal stenosis (M99.41) — the foramen is the nerve-exit aperture between vertebrae; the canal is the central spinal channel. Mixing these inflates audit risk.
• Defaulting to M48.02 (spinal stenosis, cervical region) when documentation specifically names the intervertebral foramina as the stenotic site — these are not interchangeable.
• Omitting concurrent segmental dysfunction codes (e.g., M99.01) in chiropractic claims where both diagnoses are documented and medically supported.

Clinical context

Source · Editorial summary grounded in 3 cited references ↓

Sibling codes

Other billable codes under M99.7 (laterality / anatomic variants).