ICD-10-CM > S00-T88 > S80-S89 > S86 > S86.1 > S86.11 > S86.111 S86.111 Strain of other muscle(s) and tendon(s) of posterior muscle group at lower leg level, right leg Non-Billable/Non-Specific Codes S86.111A..., initial encounterS86.111D..., subsequent encounterS86.111S..., sequela