ICDcodes.org
FY2027

S21.101AUnspecified open wound of right front wall of thorax without penetration into thoracic cavity, initial encounter

BillableUnspecifiedCC

Is S21.101A billable?

Yes, but S21.101A is an unspecified code. S21.101A is a valid, billable ICD-10-CM code for encounters from October 1, 2026 through September 30, 2027. However, S21.101A is an unspecified or catch-all code. Payers apply additional scrutiny to unspecified codes and many deny them when the medical record supports a more specific option, so check the documentation before selecting S21.101A — the more specific alternatives are listed below.

S21.101A at a glance

CodeS21.101A
DescriptionUnspecified open wound of right front wall of thorax without penetration into thoracic cavity, initial encounter
BillableYes
Code setICD-10-CM FY2027
Valid for encountersOctober 1, 2026 – September 30, 2027
7th character "A"initial encounter

What does the 7th character "A" mean in S21.101A?

In S21.101A, the 7th character A means initial encounter. The 7th character is required for S21.101A to be a valid, complete code.

Same condition, different episode of care — switch the 7th character:

Which MS-DRGs does S21.101A group to?

S21.101A sits in MDC 09 and helps define the logic of 2 MS-DRGs (version 44, FY2027). Which one a stay actually groups to also depends on procedures and secondary diagnoses.

  • 604Trauma to the Skin, Subcutaneous Tissue and Breast with MCCmedical
  • 605Trauma to the Skin, Subcutaneous Tissue and Breast without MCCmedical

As a secondary diagnosis, S21.101A is a complication or comorbidity (CC), which can move a stay into a higher-paying DRG.

How is S21.101A listed in the Alphabetic Index?

The Alphabetic Index lists these routes under S21.10, the nearest indexed parent of S21.101A. Use them to find the family, then select the specific code.

  • Wound, openthorax, thoracicfront

Excludes1 — never code together — inherited from S21

The conditions below can never be reported together with S21.101A 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 S21.101A to fully describe the condition. S21.101A 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 S21.101A, but a patient may have both at the same time. When documentation supports it, S21.101A and the excluded code may both be reported.

  • birth trauma (P10-P15)
  • obstetric trauma (O70-O71)

Excludes2 — not included here — inherited from S20-S29

The conditions below are not part of S21.101A, but a patient may have both at the same time. When documentation supports it, S21.101A 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 S21.101A is sequenced first 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

How long has S21.101A existed?

S21.101A 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.