ICD-10-CM > S00-T88 > S50-S59 > S56 > S56.2 > S56.21 S56.21 Strain of other flexor muscle, fascia and tendon at forearm level Non-Billable/Non-Specific Codes S56.211Strain of other flexor muscle, fascia and tendon at forearm level, right armS56.211A..., initial encounterS56.211D..., subsequent encounterS56.211S..., sequelaS56.212Strain of other flexor muscle, fascia and tendon at forearm level, left armS56.212A..., initial encounterS56.212D..., subsequent encounterS56.212S..., sequelaS56.219Strain of other flexor muscle, fascia and tendon at forearm level, unspecified armS56.219A..., initial encounterS56.219D..., subsequent encounterS56.219S..., sequela