ICD-10-CM > S00-T88 > S50-S59 > S56 > S56.5 > S56.59 > S56.591 S56.591 Other injury of other extensor muscle, fascia and tendon at forearm level, right arm Non-Billable/Non-Specific Codes S56.591A..., initial encounterS56.591D..., subsequent encounterS56.591S..., sequela