ICDcodes.org
FY2027

S21.321ALaceration with foreign body of right front wall of thorax with penetration into thoracic cavity, initial encounter

BillableMCC

Is S21.321A billable?

Yes — S21.321A is billable for FY2027. S21.321A is a valid, billable ICD-10-CM code at the highest level of specificity in its branch. S21.321A may be submitted for encounters from October 1, 2026 through September 30, 2027.

S21.321A at a glance

CodeS21.321A
DescriptionLaceration with foreign body of right front wall of thorax with 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 S21.321A?

In S21.321A, the 7th character A means initial encounter. The 7th character is required for S21.321A to be a valid, complete code.

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

Which MS-DRGs does S21.321A group to?

S21.321A sits in MDC 21 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.

  • 913Traumatic Injury with MCCmedical
  • 914Traumatic Injury without MCCmedical

As a secondary diagnosis, S21.321A is a major complication or comorbidity (MCC), which can move a stay into a higher-paying DRG.

How is S21.321A listed in the Alphabetic Index?

The Alphabetic Index lists these routes under S21.32, the nearest indexed parent of S21.321A. Use them to find the family, then select the specific code.

  • Lacerationthorax, thoracicwith foreign bodyfrontwith penetration into thoracic cavity
  • Lacerationthorax, thoracicfrontwithforeign bodywith penetration into thoracic cavity

Excludes1 — never code together — inherited from S21

The conditions below can never be reported together with S21.321A 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 S21.321A to fully describe the condition. S21.321A 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 S21.321A, but a patient may have both at the same time. When documentation supports it, S21.321A 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 S21.321A, but a patient may have both at the same time. When documentation supports it, S21.321A 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 S21.321A 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 S21.321A existed?

S21.321A 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.