ICD-10-CM > S00-T88 > S60-S69 > S66 > S66.4 > S66.41 > S66.419 S66.419 Strain of intrinsic muscle, fascia and tendon of unspecified thumb at wrist and hand level Non-Billable/Non-Specific Codes S66.419A..., initial encounterS66.419D..., subsequent encounterS66.419S..., sequela