ICD-10-CM > S00-T88 > S50-S59 > S56 > S56.4 > S56.42 > S56.421 S56.421 Laceration of extensor muscle, fascia and tendon of right index finger at forearm level Non-Billable/Non-Specific Codes S56.421A..., initial encounterS56.421D..., subsequent encounterS56.421S..., sequela