Acquired defect or stress fracture of the pars interarticularis at the lumbosacral junction (L5-S1 level), classified under other deforming dorsopathies. Does not include congenital spondylolysis (Q76.2) or spondylolisthesis (M43.1-).

Documentation tips

What should appear in the chart to support M43.07.

Source · Editorial brief grounded in 5 cited references ↓

• Specify the exact spinal region by name — 'lumbosacral' or 'L5-S1' to support M43.07 over the unspecified M43.00.
• Document whether the condition is acquired versus congenital; M43.07 covers acquired defects only — congenital pars defects require Q76.2.
• Note the presence or absence of vertebral displacement; if any slip is documented, the correct code shifts to M43.17 (spondylolisthesis, lumbosacral).
• Include imaging findings that confirm the pars defect — CT or MRI description of the pars interarticularis, plain film oblique views showing the 'Scotty dog' sign, or SPECT bone scan results.
• Record prior conservative treatment (physical therapy, bracing, activity restriction) to support medical necessity for advanced imaging or surgical referral.

Related CPT procedures

Procedure codes commonly billed with M43.07. 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 M43.07 and adjacent codes.

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

• Assigning M43.07 when the provider documents spondylolisthesis — spondylolysis and spondylolisthesis are distinct conditions with separate code families (M43.0 vs. M43.1); the Excludes1 note at M43.0 prohibits using both together.
• Using M43.07 for a defect documented at L4-L5 — that level maps to M43.06 (lumbar region), not lumbosacral.
• Defaulting to M43.07 when the operative or imaging report says 'lumbosacral spondylolysis' but the defect is actually a slip — verify displacement status before assigning.
• Applying Q76.2 for an adult patient with a longstanding pars defect without explicit documentation of congenital origin — absent that documentation, M43.07 is appropriate for acquired or unspecified-etiology defects.
• Failing to distinguish M43.07 from M43.06 when the provider documents 'lumbar spondylolysis' — query the provider if the note does not specify whether the L5-S1 junction is involved.

Clinical context

Source · Editorial summary grounded in 5 cited references ↓

Sibling codes

Other billable codes under M43.0 (laterality / anatomic variants).