ICD-10-CM > S00-T88 > S60-S69 > S63 > S63.6 > S63.64 S63.64 Sprain of metacarpophalangeal joint of thumb Non-Billable/Non-Specific Codes S63.641Sprain of metacarpophalangeal joint of right thumbS63.641A..., initial encounterS63.641D..., subsequent encounterS63.641S..., sequelaS63.642Sprain of metacarpophalangeal joint of left thumbS63.642A..., initial encounterS63.642D..., subsequent encounterS63.642S..., sequelaS63.649Sprain of metacarpophalangeal joint of unspecified thumbS63.649A..., initial encounterS63.649D..., subsequent encounterS63.649S..., sequela