S21 — Open wound of thorax
Not billable
Is S21 billable?
No — S21 is a non-billable header code. S21 groups more specific codes and cannot be submitted on a claim. A valid ICD-10-CM code must be reported at the highest level of specificity available in its branch. Select one of the 60 billable codes beneath S21.
Billable codes under this header
- S21.90XAUnspecified open wound of unspecified part of thorax, initial encounter
- S21.90XDUnspecified open wound of unspecified part of thorax, subsequent encounter
- S21.90XSUnspecified open wound of unspecified part of thorax, sequela
- S21.91XALaceration without foreign body of unspecified part of thorax, initial encounter
- S21.91XDLaceration without foreign body of unspecified part of thorax, subsequent encounter
- S21.91XSLaceration without foreign body of unspecified part of thorax, sequela
- S21.92XALaceration with foreign body of unspecified part of thorax, initial encounter
- S21.92XDLaceration with foreign body of unspecified part of thorax, subsequent encounter
- S21.92XSLaceration with foreign body of unspecified part of thorax, sequela
- S21.93XAPuncture wound without foreign body of unspecified part of thorax, initial encounter
- S21.93XDPuncture wound without foreign body of unspecified part of thorax, subsequent encounter
- S21.93XSPuncture wound without foreign body of unspecified part of thorax, sequela
- S21.94XAPuncture wound with foreign body of unspecified part of thorax, initial encounter
- S21.94XDPuncture wound with foreign body of unspecified part of thorax, subsequent encounter
- S21.94XSPuncture wound with foreign body of unspecified part of thorax, sequela
- S21.95XAOpen bite of unspecified part of thorax, initial encounter
- S21.95XDOpen bite of unspecified part of thorax, subsequent encounter
- S21.95XSOpen bite of unspecified part of thorax, sequela
- S21.001AUnspecified open wound of right breast, initial encounter
- S21.001DUnspecified open wound of right breast, subsequent encounter
- S21.001SUnspecified open wound of right breast, sequela
- S21.002AUnspecified open wound of left breast, initial encounter
- S21.002DUnspecified open wound of left breast, subsequent encounter
- S21.002SUnspecified open wound of left breast, sequela
- S21.009AUnspecified open wound of unspecified breast, initial encounter
- S21.009DUnspecified open wound of unspecified breast, subsequent encounter
- S21.009SUnspecified open wound of unspecified breast, sequela
- S21.011ALaceration without foreign body of right breast, initial encounter
- S21.011DLaceration without foreign body of right breast, subsequent encounter
- S21.011SLaceration without foreign body of right breast, sequela
- S21.012ALaceration without foreign body of left breast, initial encounter
- S21.012DLaceration without foreign body of left breast, subsequent encounter
- S21.012SLaceration without foreign body of left breast, sequela
- S21.019ALaceration without foreign body of unspecified breast, initial encounter
- S21.019DLaceration without foreign body of unspecified breast, subsequent encounter
- S21.019SLaceration without foreign body of unspecified breast, sequela
- S21.021ALaceration with foreign body of right breast, initial encounter
- S21.021DLaceration with foreign body of right breast, subsequent encounter
- S21.021SLaceration with foreign body of right breast, sequela
- S21.022ALaceration with foreign body of left breast, initial encounter
- S21.022DLaceration with foreign body of left breast, subsequent encounter
- S21.022SLaceration with foreign body of left breast, sequela
- S21.029ALaceration with foreign body of unspecified breast, initial encounter
- S21.029DLaceration with foreign body of unspecified breast, subsequent encounter
- S21.029SLaceration with foreign body of unspecified breast, sequela
- S21.031APuncture wound without foreign body of right breast, initial encounter
- S21.031DPuncture wound without foreign body of right breast, subsequent encounter
- S21.031SPuncture wound without foreign body of right breast, sequela
- S21.032APuncture wound without foreign body of left breast, initial encounter
- S21.032DPuncture wound without foreign body of left breast, subsequent encounter
- S21.032SPuncture wound without foreign body of left breast, sequela
- S21.039APuncture wound without foreign body of unspecified breast, initial encounter
- S21.039DPuncture wound without foreign body of unspecified breast, subsequent encounter
- S21.039SPuncture wound without foreign body of unspecified breast, sequela
- S21.041APuncture wound with foreign body of right breast, initial encounter
- S21.041DPuncture wound with foreign body of right breast, subsequent encounter
- S21.041SPuncture wound with foreign body of right breast, sequela
- S21.042APuncture wound with foreign body of left breast, initial encounter
- S21.042DPuncture wound with foreign body of left breast, subsequent encounter
- S21.042SPuncture wound with foreign body of left breast, sequela
S21 at a glance
| Code | S21 |
|---|---|
| Description | Open wound of thorax |
| Billable | No — header code |
| Code set | ICD-10-CM FY2027 |
| Valid for encounters | October 1, 2026 – September 30, 2027 |
Excludes1 — never code together
The conditions below can never be reported together with S21 on the same claim. An Excludes1 note means the two conditions cannot occur in the same patient, so reporting both is a coding error.
- traumatic amputation (partial) of thorax (S28.1)
Code also
Two codes may be needed to describe the condition fully. Whether S21 is sequenced first depends on the reason for the encounter.
Use additional code — inherited from Chapter 19
Report an additional code alongside S21 to fully describe the condition. S21 is sequenced first.
- code to identify any retained foreign body, if applicable (Z18.-)
Excludes2 — not included here — inherited from Chapter 19
The conditions below are not part of S21, but a patient may have both at the same time. When documentation supports it, S21 and the excluded code may both be reported.
Excludes2 — not included here — inherited from S20-S29
The conditions below are not part of S21, but a patient may have both at the same time. When documentation supports it, S21 and the excluded code may both be reported.
- burns and corrosions (T20-T32)
- effects of foreign body in bronchus (T17.5)
- effects of foreign body in esophagus (T18.1)
- effects of foreign body in lung (T17.8)
- effects of foreign body in trachea (T17.4)
- frostbite (T33-T34)
- injuries of axilla
- injuries of clavicle
- injuries of scapular region
- injuries of shoulder
- insect bite or sting, venomous (T63.4)
What codes fall under S21? (6)
- S21.0Open wound of breastnot billable
- S21.1Open wound of front wall of thorax without penetration into thoracic cavitynot billable
- S21.2Open wound of back wall of thorax without penetration into thoracic cavitynot billable
- S21.3Open wound of front wall of thorax with penetration into thoracic cavitynot billable
- S21.4Open wound of back wall of thorax with penetration into thoracic cavitynot billable
- S21.9Open wound of unspecified part of thoraxnot billable
How long has S21 existed?
S21 has been in ICD-10-CM since at least FY2016, the earliest fiscal year on record here.
Derived from the official order files for FY2016–FY2026. FY2017 and FY2020 publish no order file, so those years are not covered.
Which codes are confused with S21?
ICD-10-CM declares these codes mutually exclusive with S21 — exactly one of each pair can be correct for a given encounter.