ICD-10-CM 2027 diagnosis code
S21Open wound of thorax
Not billable — use a more specific code
S21 is a header code, so it can't be reported by itself. Choose one of the 6 more specific codes beneath it.
Code unchanged since ICD-10-CM took effect on October 1, 2015. Source: official FY2027 ICD-10-CM release from CDC/NCHS and CMS. Page updated September 29, 2026. About our data
About S21
S21 is the ICD-10-CM diagnosis code for open wound of thorax. It belongs to block S20-S29 (injuries to the thorax) and chapter 19 (injury, poisoning and certain other consequences of external causes). It is a header code, so it can't be reported by itself; one of its 6 subcodes must be used instead.
To report this condition, pick the subcode that matches the documentation: S21.0 (breast), S21.1 (cavity), S21.2 (cavity), S21.3 (cavity), S21.4 (cavity) and S21.9 (thorax).
Don't report S21 together with the conditions in its Excludes1 note: traumatic amputation (partial) of thorax (S28.1).
It has been part of ICD-10-CM since the code set took effect on October 1, 2015 and hasn't changed since.
Specific codes under S21
- S21.0Open wound of breast
- S21.1Open wound of front wall of thorax without penetration into thoracic cavity
- S21.10Unspecified open wound of front wall of thorax without penetration into thoracic cavity
- S21.101Unspecified open wound of right front wall of thorax without penetration into thoracic cavity
- S21.102Unspecified open wound of left front wall of thorax without penetration into thoracic cavity
- S21.109Unspecified open wound of unspecified front wall of thorax without penetration into thoracic cavity
- S21.11Laceration without foreign body of front wall of thorax without penetration into thoracic cavity
- S21.111Laceration without foreign body of right front wall of thorax without penetration into thoracic cavity
- S21.112Laceration without foreign body of left front wall of thorax without penetration into thoracic cavity
- S21.119Laceration without foreign body of unspecified front wall of thorax without penetration into thoracic cavity
- S21.12Laceration with foreign body of front wall of thorax without penetration into thoracic cavity
- S21.121Laceration with foreign body of right front wall of thorax without penetration into thoracic cavity
- S21.122Laceration with foreign body of left front wall of thorax without penetration into thoracic cavity
- S21.129Laceration with foreign body of unspecified front wall of thorax without penetration into thoracic cavity
- S21.13Puncture wound without foreign body of front wall of thorax without penetration into thoracic cavity
- S21.131Puncture wound without foreign body of right front wall of thorax without penetration into thoracic cavity
- S21.132Puncture wound without foreign body of left front wall of thorax without penetration into thoracic cavity
- S21.139Puncture wound without foreign body of unspecified front wall of thorax without penetration into thoracic cavity
- S21.14Puncture wound with foreign body of front wall of thorax without penetration into thoracic cavity
- S21.141Puncture wound with foreign body of right front wall of thorax without penetration into thoracic cavity
- S21.142Puncture wound with foreign body of left front wall of thorax without penetration into thoracic cavity
- S21.149Puncture wound with foreign body of unspecified front wall of thorax without penetration into thoracic cavity
- S21.15Open bite of front wall of thorax without penetration into thoracic cavity
- S21.10Unspecified open wound of front wall of thorax without penetration into thoracic cavity
- S21.2Open wound of back wall of thorax without penetration into thoracic cavity
- S21.20Unspecified open wound of back wall of thorax without penetration into thoracic cavity
- S21.201Unspecified open wound of right back wall of thorax without penetration into thoracic cavity
- S21.202Unspecified open wound of left back wall of thorax without penetration into thoracic cavity
- S21.209Unspecified open wound of unspecified back wall of thorax without penetration into thoracic cavity
- S21.21Laceration without foreign body of back wall of thorax without penetration into thoracic cavity
- S21.211Laceration without foreign body of right back wall of thorax without penetration into thoracic cavity
- S21.212Laceration without foreign body of left back wall of thorax without penetration into thoracic cavity
- S21.219Laceration without foreign body of unspecified back wall of thorax without penetration into thoracic cavity
- S21.22Laceration with foreign body of back wall of thorax without penetration into thoracic cavity
- S21.221Laceration with foreign body of right back wall of thorax without penetration into thoracic cavity
- S21.222Laceration with foreign body of left back wall of thorax without penetration into thoracic cavity
- S21.229Laceration with foreign body of unspecified back wall of thorax without penetration into thoracic cavity
- S21.23Puncture wound without foreign body of back wall of thorax without penetration into thoracic cavity
- S21.231Puncture wound without foreign body of right back wall of thorax without penetration into thoracic cavity
- S21.232Puncture wound without foreign body of left back wall of thorax without penetration into thoracic cavity
- S21.239Puncture wound without foreign body of unspecified back wall of thorax without penetration into thoracic cavity
- S21.24Puncture wound with foreign body of back wall of thorax without penetration into thoracic cavity
- S21.241Puncture wound with foreign body of right back wall of thorax without penetration into thoracic cavity
- S21.242Puncture wound with foreign body of left back wall of thorax without penetration into thoracic cavity
- S21.249Puncture wound with foreign body of unspecified back wall of thorax without penetration into thoracic cavity
- S21.25Open bite of back wall of thorax without penetration into thoracic cavity
- S21.20Unspecified open wound of back wall of thorax without penetration into thoracic cavity
- S21.3Open wound of front wall of thorax with penetration into thoracic cavity
- S21.30Unspecified open wound of front wall of thorax with penetration into thoracic cavity
- S21.31Laceration without foreign body of front wall of thorax with penetration into thoracic cavity
- S21.311Laceration without foreign body of right front wall of thorax with penetration into thoracic cavity
- S21.312Laceration without foreign body of left front wall of thorax with penetration into thoracic cavity
- S21.319Laceration without foreign body of unspecified front wall of thorax with penetration into thoracic cavity
- S21.32Laceration with foreign body of front wall of thorax with penetration into thoracic cavity
- S21.321Laceration with foreign body of right front wall of thorax with penetration into thoracic cavity
- S21.322Laceration with foreign body of left front wall of thorax with penetration into thoracic cavity
- S21.329Laceration with foreign body of unspecified front wall of thorax with penetration into thoracic cavity
- S21.33Puncture wound without foreign body of front wall of thorax with penetration into thoracic cavity
- S21.331Puncture wound without foreign body of right front wall of thorax with penetration into thoracic cavity
- S21.332Puncture wound without foreign body of left front wall of thorax with penetration into thoracic cavity
- S21.339Puncture wound without foreign body of unspecified front wall of thorax with penetration into thoracic cavity
- S21.34Puncture wound with foreign body of front wall of thorax with penetration into thoracic cavity
- S21.341Puncture wound with foreign body of right front wall of thorax with penetration into thoracic cavity
- S21.342Puncture wound with foreign body of left front wall of thorax with penetration into thoracic cavity
- S21.349Puncture wound with foreign body of unspecified front wall of thorax with penetration into thoracic cavity
- S21.35Open bite of front wall of thorax with penetration into thoracic cavity
- S21.4Open wound of back wall of thorax with penetration into thoracic cavity
- S21.40Unspecified open wound of back wall of thorax with penetration into thoracic cavity
- S21.41Laceration without foreign body of back wall of thorax with penetration into thoracic cavity
- S21.411Laceration without foreign body of right back wall of thorax with penetration into thoracic cavity
- S21.412Laceration without foreign body of left back wall of thorax with penetration into thoracic cavity
- S21.419Laceration without foreign body of unspecified back wall of thorax with penetration into thoracic cavity
- S21.42Laceration with foreign body of back wall of thorax with penetration into thoracic cavity
- S21.421Laceration with foreign body of right back wall of thorax with penetration into thoracic cavity
- S21.422Laceration with foreign body of left back wall of thorax with penetration into thoracic cavity
- S21.429Laceration with foreign body of unspecified back wall of thorax with penetration into thoracic cavity
- S21.43Puncture wound without foreign body of back wall of thorax with penetration into thoracic cavity
- S21.431Puncture wound without foreign body of right back wall of thorax with penetration into thoracic cavity
- S21.432Puncture wound without foreign body of left back wall of thorax with penetration into thoracic cavity
- S21.439Puncture wound without foreign body of unspecified back wall of thorax with penetration into thoracic cavity
- S21.44Puncture wound with foreign body of back wall of thorax with penetration into thoracic cavity
- S21.441Puncture wound with foreign body of right back wall of thorax with penetration into thoracic cavity
- S21.442Puncture wound with foreign body of left back wall of thorax with penetration into thoracic cavity
- S21.449Puncture wound with foreign body of unspecified back wall of thorax with penetration into thoracic cavity
- S21.45Open bite of back wall of thorax with penetration into thoracic cavity
- S21.9Open wound of unspecified part of thorax
- S21.90Unspecified open wound of unspecified part of thorax
- S21.91Laceration without foreign body of unspecified part of thorax
- S21.92Laceration with foreign body of unspecified part of thorax
- S21.93Puncture wound without foreign body of unspecified part of thorax
- S21.94Puncture wound with foreign body of unspecified part of thorax
- S21.95Open bite of unspecified part of thorax
Coding notes
Excludes1Not coded here — never report together with this code
- traumatic amputation (partial) of thorax (S28.1)
Code alsoTwo codes may be needed; sequencing depends on circumstances
Notes that apply from higher levels
Instructions written at a parent level also apply to S21.
Broader instructions also apply from S20-S29 Injuries to the thorax and Chapter 19: Injury, poisoning and certain other consequences of external causes.
Codes whose notes reference S21
Code history
- 2016
- 2017
- 2018
- 2019
- 2020
- 2021
- 2022
- 2023
- 2024
- 2025
- 2026
- 2027
- FY2016 (effective 10/1/2015): Added (first year of ICD-10-CM)
- No changes since FY2016.
Common questions about S21
Is S21 billable?
- No. S21 is a header code. Report one of its more specific subcodes instead.