ICD-10-CM > S00-T88 > S20-S29 > S21 > S21.4 > S21.44 S21.44 Puncture wound with foreign body of back wall of thorax with penetration into thoracic cavity Non-Billable/Non-Specific Codes S21.441Puncture wound with foreign body of right back wall of thorax with penetration into thoracic cavityS21.441A..., initial encounterS21.441D..., subsequent encounterS21.441S..., sequelaS21.442Puncture wound with foreign body of left back wall of thorax with penetration into thoracic cavityS21.442A..., initial encounterS21.442D..., subsequent encounterS21.442S..., sequelaS21.449Puncture wound with foreign body of unspecified back wall of thorax with penetration into thoracic cavityS21.449A..., initial encounterS21.449D..., subsequent encounterS21.449S..., sequela