S21.0 — Open wound of breast
S21.0 is a non-billable header ICD-10-CM code for open wound of breast. 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
Other codes that can never be billed with S21.0
These codes carry an Excludes1 note pointing at S21.0. The conflict binds both ways, but ICD-10-CM only writes it down on one side — so you would not find this by reading S21.0 alone.
- S20.17Other superficial bite of breast
Risk adjustment
S21.0 does not map to an HCC and does not risk-adjust under CMS-HCC V28. That is normal — most ICD-10 codes do not. It still needs to be coded correctly; it just will not move a RAF score.
Code to one of these instead S21.0
6 child codes. Green means billable.
Related codes at this level
Codes that share S21. If S21.0 is not quite right, the correct code is usually one of these.
- 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
Questions about S21.0
- Is S21.0 a billable ICD-10-CM code?
- No. S21.0 is a non-billable header code. Code to a higher level of specificity using one of its child codes.
- Where does S21.0 sit in the tabular list?
- Injury, poisoning and certain other consequences of external causes (S00-T88), in the block Injuries to the thorax (S20-S29).