ICD-10-CM > S00-T88 > S80-S89 > S86 > S86.1 > S86.10 > S86.109 S86.109 Unspecified injury of other muscle(s) and tendon(s) of posterior muscle group at lower leg level, unspecified leg Non-Billable/Non-Specific Codes S86.109A..., initial encounterS86.109D..., subsequent encounterS86.109S..., sequela