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