ICD-10-CM > S00-T88 > S60-S69 > S63 > S63.6 > S63.63 > S63.631 S63.631 Sprain of interphalangeal joint of left index finger Non-Billable/Non-Specific Codes S63.631A..., initial encounterS63.631D..., subsequent encounterS63.631S..., sequela