Acquired anterior spinal curvature localized to the thoracolumbar junction (T10–L2 region) that arises from postural habits rather than structural or congenital deformity.

Documentation tips

What should appear in the chart to support M40.45.

Source · Editorial brief grounded in 6 cited references ↓

• Specify the thoracolumbar region by name — a note that says only 'lumbar lordosis' or 'back hyperlordosis' does not support M40.45.
• Document the postural or acquired etiology explicitly; distinguish from congenital or postprocedural lordosis, which map to separate code blocks.
• Include standing lateral radiograph findings: Cobb angle measurement, levels involved, and absence of vertebral fractures or structural deformity that would suggest a secondary cause.
• If an underlying systemic condition (e.g., muscular dystrophy, connective tissue disorder) is contributing to the curvature, document it as the primary diagnosis and sequence M40.45 after it per the 'code first underlying disease' instruction at M40.4.
• Note any functional limitations, conservative treatment history (physical therapy, bracing), and pain pattern to support medical necessity for associated services.

Related CPT procedures

Procedure codes commonly billed with M40.45. 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 M40.45 and adjacent codes.

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

• Assigning M40.45 when documentation only references 'lumbar lordosis' — the correct code in that scenario is M40.46 (lumbar region) or M40.47 (lumbosacral region).
• Using M40.45 for congenital lordosis — congenital kyphosis and lordosis is an Excludes1 condition under M40, requiring Q76.4 instead.
• Failing to sequence an underlying disease first when postural lordosis is secondary to a systemic or neuromuscular condition; the tabular 'code first' note at M40.4 makes this a sequencing error.
• Dropping to the unspecified site code M40.40 when the provider has documented thoracolumbar involvement — specificity is available and should be captured.
• Confusing postural lordosis (M40.45) with postural kyphosis at the same region (M40.05); review the direction of curvature documented before selecting the code.

Clinical context

Source · Editorial summary grounded in 6 cited references ↓

Sibling codes

Other billable codes under M40.4 (laterality / anatomic variants).