ICD-10-CM > S00-T88 > S60-S69 > S66 > S66.0 > S66.00 S66.00 Unspecified injury of long flexor muscle, fascia and tendon of thumb at wrist and hand level Non-Billable/Non-Specific Codes S66.001Unspecified injury of long flexor muscle, fascia and tendon of right thumb at wrist and hand levelS66.001A..., initial encounterS66.001D..., subsequent encounterS66.001S..., sequelaS66.002Unspecified injury of long flexor muscle, fascia and tendon of left thumb at wrist and hand levelS66.002A..., initial encounterS66.002D..., subsequent encounterS66.002S..., sequelaS66.009Unspecified injury of long flexor muscle, fascia and tendon of unspecified thumb at wrist and hand levelS66.009A..., initial encounterS66.009D..., subsequent encounterS66.009S..., sequela