S21Header code — not billable
Open wound of thorax
- Chapter
- 19. Injury, poisoning and certain other consequences of external causes
- Category
- S21
- Effective date
- October 1, 2026
Related codes in category S21
S21.0Open wound of breastS21.00Unspecified open wound of breastS21.001Unspecified open wound of right breastS21.001AUnspecified open wound of right breast, initial encounterYesS21.001DUnspecified open wound of right breast, subsequent encounterYesS21.001SUnspecified open wound of right breast, sequelaYesS21.002Unspecified open wound of left breastS21.002AUnspecified open wound of left breast, initial encounterYesS21.002DUnspecified open wound of left breast, subsequent encounterYesS21.002SUnspecified open wound of left breast, sequelaYesS21.009Unspecified open wound of unspecified breastS21.009AUnspecified open wound of unspecified breast, init encntrYes
Frequently asked questions
What is ICD-10 code S21?
S21 is an ICD-10-CM diagnosis code for Open wound of thorax.
Is S21 a billable code?
No. S21 is a category/header code, not billable on its own — use one of its more specific child codes instead.
What ICD-10-CM chapter is S21 in?
S21 falls under Chapter 19: Injury, poisoning and certain other consequences of external causes.
When did S21 become effective?
S21 has been effective since October 1, 2026, per the CMS/CDC ICD-10-CM annual release.
What other codes are related to S21?
S21 belongs to category S21, which includes 12 other codes — see the related codes list on this page.
ICD-10-CM data maintained by CDC/CMS (public domain). Always verify codes with authoritative sources before making coding or billing decisions.