ICD-10-CM > S00-T88 > S50-S59 > S56 > S56.8 > S56.89 > S56.899 S56.899 Other injury of other muscles, fascia and tendons at forearm level, unspecified arm Non-Billable/Non-Specific Codes S56.899A..., initial encounterS56.899D..., subsequent encounterS56.899S..., sequela