ICD-10-CM > S00-T88 > S50-S59 > S56 > S56.0 > S56.00 > S56.009 S56.009 Unspecified injury of flexor muscle, fascia and tendon of unspecified thumb at forearm level Non-Billable/Non-Specific Codes S56.009A..., initial encounterS56.009D..., subsequent encounterS56.009S..., sequela