ICD-10-CM > S00-T88 > S60-S69 > S66 > S66.3 > S66.31 > S66.310 S66.310 Strain of extensor muscle, fascia and tendon of right index finger at wrist and hand level Non-Billable/Non-Specific Codes S66.310A..., initial encounterS66.310D..., subsequent encounterS66.310S..., sequela