ICD-10-CM > S00-T88 > S20-S29 > S21 > S21.4 > S21.43 S21.43 Puncture wound without foreign body of back wall of thorax with penetration into thoracic cavity Non-Billable/Non-Specific Codes S21.431Puncture wound without foreign body of right back wall of thorax with penetration into thoracic cavityS21.431A..., initial encounterS21.431D..., subsequent encounterS21.431S..., sequelaS21.432Puncture wound without foreign body of left back wall of thorax with penetration into thoracic cavityS21.432A..., initial encounterS21.432D..., subsequent encounterS21.432S..., sequelaS21.439Puncture wound without foreign body of unspecified back wall of thorax with penetration into thoracic cavityS21.439A..., initial encounterS21.439D..., subsequent encounterS21.439S..., sequela