ICD-10-CM > S00-T88 > S60-S69 > S66 > S66.2 > S66.29 > S66.299 S66.299 Other specified injury of extensor muscle, fascia and tendon of unspecified thumb at wrist and hand level Non-Billable/Non-Specific Codes S66.299A..., initial encounterS66.299D..., subsequent encounterS66.299S..., sequela