ICD-10-CM > M00-M99 > M20-M25 > M21 > M21.9 > M21.93 M21.93 Unspecified acquired deformity of forearm Non-Billable/Non-Specific Codes M21.931Unspecified acquired deformity of right forearmM21.932Unspecified acquired deformity of left forearmM21.939Unspecified acquired deformity of unspecified forearm