ICD-10-CM > M00-M99 > M20-M25 > M21 > M21.2 > M21.24 M21.24 Flexion deformity, finger joints Non-Billable/Non-Specific Codes M21.241Flexion deformity, right finger jointsM21.242Flexion deformity, left finger jointsM21.249Flexion deformity, unspecified finger joints