ICD-10-CM > S00-T88 > S10-S19 > S13 > S13.1 > S13.18 > S13.180 S13.180 Subluxation of C7/T1 cervical vertebrae Non-Billable/Non-Specific Codes S13.180A..., initial encounterS13.180D..., subsequent encounterS13.180S..., sequela