ICD-10-CM > S00-T88 > S80-S89 > S86 > S86.1 > S86.10 S86.10 Unspecified injury of other muscle(s) and tendon(s) of posterior muscle group at lower leg level Non-Billable/Non-Specific Codes S86.101Unspecified injury of other muscle(s) and tendon(s) of posterior muscle group at lower leg level, right legS86.101A..., initial encounterS86.101D..., subsequent encounterS86.101S..., sequelaS86.102Unspecified injury of other muscle(s) and tendon(s) of posterior muscle group at lower leg level, left legS86.102A..., initial encounterS86.102D..., subsequent encounterS86.102S..., sequelaS86.109Unspecified injury of other muscle(s) and tendon(s) of posterior muscle group at lower leg level, unspecified legS86.109A..., initial encounterS86.109D..., subsequent encounterS86.109S..., sequela