S21.4 — Open wound of back wall of thorax with penetration into thoracic cavity
Not billable
Is S21.4 billable?
No — S21.4 is a non-billable header code. S21.4 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 54 billable codes beneath S21.4.
Billable codes under this header
- S21.401AUnspecified open wound of right back wall of thorax with penetration into thoracic cavity, initial encounter
- S21.401DUnspecified open wound of right back wall of thorax with penetration into thoracic cavity, subsequent encounter
- S21.401SUnspecified open wound of right back wall of thorax with penetration into thoracic cavity, sequela
- S21.402AUnspecified open wound of left back wall of thorax with penetration into thoracic cavity, initial encounter
- S21.402DUnspecified open wound of left back wall of thorax with penetration into thoracic cavity, subsequent encounter
- S21.402SUnspecified open wound of left back wall of thorax with penetration into thoracic cavity, sequela
- S21.409AUnspecified open wound of unspecified back wall of thorax with penetration into thoracic cavity, initial encounter
- S21.409DUnspecified open wound of unspecified back wall of thorax with penetration into thoracic cavity, subsequent encounter
- S21.409SUnspecified open wound of unspecified back wall of thorax with penetration into thoracic cavity, sequela
- S21.411ALaceration without foreign body of right back wall of thorax with penetration into thoracic cavity, initial encounter
- S21.411DLaceration without foreign body of right back wall of thorax with penetration into thoracic cavity, subsequent encounter
- S21.411SLaceration without foreign body of right back wall of thorax with penetration into thoracic cavity, sequela
- S21.412ALaceration without foreign body of left back wall of thorax with penetration into thoracic cavity, initial encounter
- S21.412DLaceration without foreign body of left back wall of thorax with penetration into thoracic cavity, subsequent encounter
- S21.412SLaceration without foreign body of left back wall of thorax with penetration into thoracic cavity, sequela
- S21.419ALaceration without foreign body of unspecified back wall of thorax with penetration into thoracic cavity, initial encounter
- S21.419DLaceration without foreign body of unspecified back wall of thorax with penetration into thoracic cavity, subsequent encounter
- S21.419SLaceration without foreign body of unspecified back wall of thorax with penetration into thoracic cavity, sequela
- S21.421ALaceration with foreign body of right back wall of thorax with penetration into thoracic cavity, initial encounter
- S21.421DLaceration with foreign body of right back wall of thorax with penetration into thoracic cavity, subsequent encounter
- S21.421SLaceration with foreign body of right back wall of thorax with penetration into thoracic cavity, sequela
- S21.422ALaceration with foreign body of left back wall of thorax with penetration into thoracic cavity, initial encounter
- S21.422DLaceration with foreign body of left back wall of thorax with penetration into thoracic cavity, subsequent encounter
- S21.422SLaceration with foreign body of left back wall of thorax with penetration into thoracic cavity, sequela
- S21.429ALaceration with foreign body of unspecified back wall of thorax with penetration into thoracic cavity, initial encounter
- S21.429DLaceration with foreign body of unspecified back wall of thorax with penetration into thoracic cavity, subsequent encounter
- S21.429SLaceration with foreign body of unspecified back wall of thorax with penetration into thoracic cavity, sequela
- S21.431APuncture wound without foreign body of right back wall of thorax with penetration into thoracic cavity, initial encounter
- S21.431DPuncture wound without foreign body of right back wall of thorax with penetration into thoracic cavity, subsequent encounter
- S21.431SPuncture wound without foreign body of right back wall of thorax with penetration into thoracic cavity, sequela
- S21.432APuncture wound without foreign body of left back wall of thorax with penetration into thoracic cavity, initial encounter
- S21.432DPuncture wound without foreign body of left back wall of thorax with penetration into thoracic cavity, subsequent encounter
- S21.432SPuncture wound without foreign body of left back wall of thorax with penetration into thoracic cavity, sequela
- S21.439APuncture wound without foreign body of unspecified back wall of thorax with penetration into thoracic cavity, initial encounter
- S21.439DPuncture wound without foreign body of unspecified back wall of thorax with penetration into thoracic cavity, subsequent encounter
- S21.439SPuncture wound without foreign body of unspecified back wall of thorax with penetration into thoracic cavity, sequela
- S21.441APuncture wound with foreign body of right back wall of thorax with penetration into thoracic cavity, initial encounter
- S21.441DPuncture wound with foreign body of right back wall of thorax with penetration into thoracic cavity, subsequent encounter
- S21.441SPuncture wound with foreign body of right back wall of thorax with penetration into thoracic cavity, sequela
- S21.442APuncture wound with foreign body of left back wall of thorax with penetration into thoracic cavity, initial encounter
- S21.442DPuncture wound with foreign body of left back wall of thorax with penetration into thoracic cavity, subsequent encounter
- S21.442SPuncture wound with foreign body of left back wall of thorax with penetration into thoracic cavity, sequela
- S21.449APuncture wound with foreign body of unspecified back wall of thorax with penetration into thoracic cavity, initial encounter
- S21.449DPuncture wound with foreign body of unspecified back wall of thorax with penetration into thoracic cavity, subsequent encounter
- S21.449SPuncture wound with foreign body of unspecified back wall of thorax with penetration into thoracic cavity, sequela
- S21.451AOpen bite of right back wall of thorax with penetration into thoracic cavity, initial encounter
- S21.451DOpen bite of right back wall of thorax with penetration into thoracic cavity, subsequent encounter
- S21.451SOpen bite of right back wall of thorax with penetration into thoracic cavity, sequela
- S21.452AOpen bite of left back wall of thorax with penetration into thoracic cavity, initial encounter
- S21.452DOpen bite of left back wall of thorax with penetration into thoracic cavity, subsequent encounter
- S21.452SOpen bite of left back wall of thorax with penetration into thoracic cavity, sequela
- S21.459AOpen bite of unspecified back wall of thorax with penetration into thoracic cavity, initial encounter
- S21.459DOpen bite of unspecified back wall of thorax with penetration into thoracic cavity, subsequent encounter
- S21.459SOpen bite of unspecified back wall of thorax with penetration into thoracic cavity, sequela
S21.4 at a glance
| Code | S21.4 |
|---|---|
| Description | Open wound of back wall of thorax with penetration into thoracic cavity |
| Billable | No — header code |
| Code set | ICD-10-CM FY2027 |
| Valid for encounters | October 1, 2026 – September 30, 2027 |
Excludes1 — never code together — inherited from S21
The conditions below can never be reported together with S21.4 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)
Use additional code — inherited from Chapter 19
Report an additional code alongside S21.4 to fully describe the condition. S21.4 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 S21.4, but a patient may have both at the same time. When documentation supports it, S21.4 and the excluded code may both be reported.
Excludes2 — not included here — inherited from S20-S29
The conditions below are not part of S21.4, but a patient may have both at the same time. When documentation supports it, S21.4 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)
Code also — inherited from S21
Two codes may be needed to describe the condition fully. Whether S21.4 is sequenced first depends on the reason for the encounter.
What codes fall under S21.4? (6)
- S21.40Unspecified open wound of back wall of thorax with penetration into thoracic cavitynot billable
- S21.41Laceration without foreign body of back wall of thorax with penetration into thoracic cavitynot billable
- S21.42Laceration with foreign body of back wall of thorax with penetration into thoracic cavitynot billable
- S21.43Puncture wound without foreign body of back wall of thorax with penetration into thoracic cavitynot billable
- S21.44Puncture wound with foreign body of back wall of thorax with penetration into thoracic cavitynot billable
- S21.45Open bite of back wall of thorax with penetration into thoracic cavitynot billable
How long has S21.4 existed?
S21.4 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.
What other codes are in the S21 family? (5)
- 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
- S21.9Open wound of unspecified part of thoraxnot billable