ICD-10-CM > S00-T88 > S60-S69 > S66 > S66.5 > S66.59 > S66.591 S66.591 Other injury of intrinsic muscle, fascia and tendon of left index finger at wrist and hand level Non-Billable/Non-Specific Codes S66.591A..., initial encounterS66.591D..., subsequent encounterS66.591S..., sequela