ICD-10-CM > S00-T88 > S20-S29 > S21 > S21.2 > S21.20 S21.20 Unspecified open wound of back wall of thorax without penetration into thoracic cavity Non-Billable/Non-Specific Codes S21.201Unspecified open wound of right back wall of thorax without penetration into thoracic cavityS21.201A..., initial encounterS21.201D..., subsequent encounterS21.201S..., sequelaS21.202Unspecified open wound of left back wall of thorax without penetration into thoracic cavityS21.202A..., initial encounterS21.202D..., subsequent encounterS21.202S..., sequelaS21.209Unspecified open wound of unspecified back wall of thorax without penetration into thoracic cavityS21.209A..., initial encounterS21.209D..., subsequent encounterS21.209S..., sequela