ICD-10-CM > S00-T88 > S60-S69 > S66 > S66.1 > S66.12 > S66.121 S66.121 Laceration of flexor muscle, fascia and tendon of left index finger at wrist and hand level Non-Billable/Non-Specific Codes S66.121A..., initial encounterS66.121D..., subsequent encounterS66.121S..., sequela