ICD-10-CM > S00-T88 > S20-S29 > S21 > S21.2 > S21.25 > S21.252 S21.252 Open bite of left back wall of thorax without penetration into thoracic cavity Non-Billable/Non-Specific Codes S21.252A..., initial encounterS21.252D..., subsequent encounterS21.252S..., sequela