S21

ICD-10Non-billable category

Open wound of thorax

Official ICD-10-CM descriptor (FY2026)

Open wound of thorax

S21 is a category heading, not a billable code. CMS does not accept it on a claim; report one of the more specific codes beneath it.

Excludes1

Not coded here. An Excludes1 code should never be reported at the same time as the code above it.

  • traumatic amputation (partial) of thorax (S28.1)

Code also

Two codes may be needed; sequencing depends on the reason for the encounter.

  • any associated injury, such as:
  • injury of heart (S26.-)
  • injury of intrathoracic organs (S27.-)
  • rib fracture (S22.3-, S22.4-)
  • spinal cord injury (S24.0-, S24.1-)
  • traumatic hemopneumothorax (S27.3)
  • traumatic hemothorax (S27.1)
  • traumatic pneumothorax (S27.0)
  • wound infection

7th character

  • The appropriate 7th character is to be added to each code from category S21

Permitted 7th characters

Ainitial encounter
Dsubsequent encounter
Ssequela

More specific codes under S21

Where this code sits

Krasyn AI Coder

Get code suggestions automatically as you type notes. Free for 50 analyses.

Install for Chrome — free

Source

ICD-10-CM FY2026. Centers for Medicare & Medicaid Services (CMS) / National Center for Health Statistics (NCHS), “2026 ICD-10-CM Code Descriptions in Tabular Order” (icd10cm_order_2026.txt). Download the original file from cms.gov. Public domain (US Government work). Descriptors, billable flags and instructional notes on this page are reproduced from that file without modification. Krasyn adds no clinical guidance.

Get codes automatically as you write notes. Krasyn AI Coder for Chrome — free for 50 analyses.Install free →