Acquired spondylolisthesis — forward or backward slip of one vertebra relative to an adjacent vertebra — with the affected spinal region not documented or not specified.

Documentation tips

What should appear in the chart to support M43.10.

Source · Editorial brief grounded in 6 cited references ↓

• Name the specific spinal region in every note — lumbar, lumbosacral, thoracic, etc. — so you never need M43.10 in the first place.
• Record the vertebral levels involved (e.g., L4-L5) and the slip grade (Meyerding Grade I–IV) to support medical necessity for surgery or injection.
• Reference the imaging modality and findings — X-ray flexion-extension, MRI, or CT — including the degree of anterolisthesis or retrolisthesis documented in the radiology report.
• Distinguish degenerative, isthmic, and other etiologies in the clinical note; the ICD-10 M43.1x series does not capture etiology, but payer LCDs for fusion often require it in the narrative.
• If the provider's note says only 'spondylolisthesis,' send a query before assigning M43.10 — the level is almost always identifiable on imaging already in the chart.

Related CPT procedures

Procedure codes commonly billed with M43.10. 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 M43.10 and adjacent codes.

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

• Defaulting to M43.10 when the imaging report clearly states 'L4-L5 spondylolisthesis' — that maps to M43.16 (lumbar region), not the unspecified code.
• Using M43.10 for congenital spondylolisthesis — that is excluded from M43.1x entirely and belongs under Q76.2.
• Assigning M43.10 for an acute traumatic slip — acute traumatic lumbosacral spondylolisthesis requires S33.1xx (with appropriate 7th character); other acute traumatic sites require a vertebral fracture code.
• Failing to update M43.10 to a site-specific code after a query or addendum is returned — the amended note controls the final code assignment.
• Pairing M43.10 with a procedure code tied to a specific level (e.g., L5-S1 fusion CPT 22630) without reconciling the diagnosis level; this mismatch can trigger NCCI or payer edits.

Clinical context

Source · Editorial summary grounded in 6 cited references ↓

Sibling codes

Other billable codes under M43.1 (laterality / anatomic variants).