ICD-10-CM > M00-M99 > M20-M25 > M21 > M21.7 M21.7 Unequal limb length (acquired) Non-Billable/Non-Specific Notes The site used should correspond to the shorter limb Codes M21.70Unequal limb length (acquired), unspecified siteM21.72Unequal limb length (acquired), humerusM21.721Unequal limb length (acquired), right humerusM21.722Unequal limb length (acquired), left humerusM21.729Unequal limb length (acquired), unspecified humerusM21.73Unequal limb length (acquired), ulna and radiusM21.731Unequal limb length (acquired), right ulnaM21.732Unequal limb length (acquired), left ulnaM21.733Unequal limb length (acquired), right radiusM21.734Unequal limb length (acquired), left radiusM21.739Unequal limb length (acquired), unspecified ulna and radiusM21.75Unequal limb length (acquired), femurM21.751Unequal limb length (acquired), right femurM21.752Unequal limb length (acquired), left femurM21.759Unequal limb length (acquired), unspecified femurM21.76Unequal limb length (acquired), tibia and fibulaM21.761Unequal limb length (acquired), right tibiaM21.762Unequal limb length (acquired), left tibiaM21.763Unequal limb length (acquired), right fibulaM21.764Unequal limb length (acquired), left fibulaM21.769Unequal limb length (acquired), unspecified tibia and fibula