S21
S21: Open wound of thorax
Non-billable headerICD-10-CM
S21 is a non-billable header ICD-10-CM code for open wound of thorax. It cannot be billed on its own: choose one of the more specific child codes below. This code also requires a 7th character before it is complete.
This code requires a 7th character
The appropriate 7th character is to be added to each code from category S21
- A
- initial encounter
- D
- subsequent encounter
- S
- sequela
Excludes1: never code together
These conditions cannot occur together. Billing both on the same encounter is a denial.
- traumatic amputation (partial) of thorax (S28.1)
Code also
Both codes may be needed to describe the encounter fully. Sequencing depends on the reason for the visit.
Other codes that can never be billed with S21
Their own Excludes1 notes name this code, so the conflict is not listed above.
- S20.17Other superficial bite of breast
- S20.37Other superficial bite of front wall of thorax
- S20.47Other superficial bite of back wall of thorax
- S20.97Other superficial bite of unspecified parts of thorax
- S20.97XAOther superficial bite of unspecified parts of thorax, initial encounter
- S20.97XDOther superficial bite of unspecified parts of thorax, subsequent encounter
- S20.97XSOther superficial bite of unspecified parts of thorax, sequela
Risk adjustment
No CMS-HCC V28 category: this code does not change a RAF score.
Code history
Unchanged in every release from FY2024 to FY2027.
Code to one of these instead S21
6 child codes. Green means billable.
- S21.0Open wound of breast
- S21.1Open wound of front wall of thorax without penetration into thoracic cavity
- S21.2Open wound of back wall of thorax without penetration into thoracic cavity
- S21.3Open wound of front wall of thorax with penetration into thoracic cavity
- S21.4Open wound of back wall of thorax with penetration into thoracic cavity
- S21.9Open wound of unspecified part of thorax