ICD-10-CM > M00-M99 > M20-M25 > M25 > M25.6 > M25.64 M25.64 Stiffness of hand, not elsewhere classified Non-Billable/Non-Specific Codes M25.641Stiffness of right hand, not elsewhere classifiedM25.642Stiffness of left hand, not elsewhere classifiedM25.649Stiffness of unspecified hand, not elsewhere classified