ICD-10-CM > S00-T88 > S50-S59 > S56 > S56.2 > S56.21 > S56.212 S56.212 Strain of other flexor muscle, fascia and tendon at forearm level, left arm Non-Billable/Non-Specific Codes S56.212A..., initial encounterS56.212D..., subsequent encounterS56.212S..., sequela