M21.7
Header — not billableUnequal limb length (acquired)
The ICD-10 code for unequal limb length (acquired) is M21.7.
M21.7 is a non-billable header code. It groups related conditions but cannot be used on its own for reimbursement — select one of the 5 more specific codes below.
Documentation support
General coding-documentation guidance — not a substitute for payer-specific requirements or professional coding judgment.
- •This is a non-billable header code. Documentation must support a more specific child code before this diagnosis can be reported on a claim.
- •As a general rule, code to the highest level of specificity supported by the documentation in the medical record.
Child codes under M21.7
- M21.70Unequal limb length (acquired), unspecified site
- M21.72Unequal limb length (acquired), humerusnon-billable header
- M21.73Unequal limb length (acquired), ulna and radiusnon-billable header
- M21.75Unequal limb length (acquired), femurnon-billable header
- M21.76Unequal limb length (acquired), tibia and fibulanon-billable header
Related codes in this category
- M21.0Valgus deformity, not elsewhere classifiednon-billable header
- M21.1Varus deformity, not elsewhere classifiednon-billable header
- M21.2Flexion deformitynon-billable header
- M21.3Wrist or foot drop (acquired)non-billable header
- M21.4Flat foot [pes planus] (acquired)non-billable header
- M21.5Acquired clawhand, clubhand, clawfoot and clubfootnon-billable header
- M21.6Other acquired deformities of footnon-billable header
- M21.8Other specified acquired deformities of limbsnon-billable header
- M21.9Unspecified acquired deformity of limb and handnon-billable header
- M21.7Unequal limb length (acquired)non-billable header