ICD-10-CM > S00-T88 > S80-S89 > S86 > S86.1 > S86.19 S86.19 Other injury of other muscle(s) and tendon(s) of posterior muscle group at lower leg level Non-Billable/Non-Specific Codes S86.191Other injury of other muscle(s) and tendon(s) of posterior muscle group at lower leg level, right legS86.191A..., initial encounterS86.191D..., subsequent encounterS86.191S..., sequelaS86.192Other injury of other muscle(s) and tendon(s) of posterior muscle group at lower leg level, left legS86.192A..., initial encounterS86.192D..., subsequent encounterS86.192S..., sequelaS86.199Other injury of other muscle(s) and tendon(s) of posterior muscle group at lower leg level, unspecified legS86.199A..., initial encounterS86.199D..., subsequent encounterS86.199S..., sequela