ICD-10-CM > S00-T88 > S50-S59 > S56 > S56.3 > S56.31 > S56.319 S56.319 Strain of extensor or abductor muscles, fascia and tendons of unspecified thumb at forearm level Non-Billable/Non-Specific Codes S56.319A..., initial encounterS56.319D..., subsequent encounterS56.319S..., sequela