ICD-10-CM > S00-T88 > S60-S69 > S66 > S66.3 > S66.31 > S66.313 S66.313 Strain of extensor muscle, fascia and tendon of left middle finger at wrist and hand level Non-Billable/Non-Specific Codes S66.313A..., initial encounterS66.313D..., subsequent encounterS66.313S..., sequela