ICD-10-CM > S00-T88 > S60-S69 > S66 > S66.4 > S66.49 > S66.491 S66.491 Other specified injury of intrinsic muscle, fascia and tendon of right thumb at wrist and hand level Non-Billable/Non-Specific Codes S66.491A..., initial encounterS66.491D..., subsequent encounterS66.491S..., sequela