ICD-10-CM > S00-T88 > S60-S69 > S66 > S66.3 > S66.30 > S66.301 S66.301 Unspecified injury of extensor muscle, fascia and tendon of left index finger at wrist and hand level Non-Billable/Non-Specific Codes S66.301A..., initial encounterS66.301D..., subsequent encounterS66.301S..., sequela