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v1.0.0
ICD-10 Guide
ICD-10 CodesS21.40

S21.40

Billable

Unspecified open wound of back wall of thorax with penetration into thoracic cavity

BILLABLE STATUSYes
IMPLEMENTATION DATEOctober 1, 2015
LAST UPDATED09/23/2025

Code Description

ICD-10 S21.40 is a billable code used to indicate a diagnosis of unspecified open wound of back wall of thorax with penetration into thoracic cavity.

Key Diagnostic Point:

An unspecified open wound of the back wall of the thorax with penetration into the thoracic cavity indicates a traumatic injury that compromises the integrity of the thoracic wall, potentially leading to serious complications such as pneumothorax, hemothorax, or cardiac injuries. This type of injury often results from penetrating trauma, such as gunshot wounds or stab wounds, and can vary in severity based on the depth and extent of the wound. The thoracic cavity houses vital organs, including the lungs and heart, making any injury in this area critical. Clinicians must assess for associated injuries, such as rib fractures, which can exacerbate the condition by causing further damage to the pleura or mediastinum. Management may involve surgical intervention to repair the wound, drain fluid collections, or address any cardiac injuries. Accurate coding is essential for appropriate treatment planning and reimbursement, as well as for tracking outcomes in trauma care.

Code Complexity Analysis

Complexity Rating: Medium

Medium Complexity

Complexity Factors

  • Variability in documentation quality regarding the nature of the wound
  • Need for detailed descriptions of associated injuries (e.g., rib fractures, pneumothorax)
  • Potential for multiple codes to be applicable based on the extent of injury
  • Differentiation between open and closed wounds in clinical documentation

Audit Risk Factors

  • Inadequate documentation of the mechanism of injury
  • Failure to document associated injuries or complications
  • Inconsistent coding of similar injuries across different encounters
  • Lack of clarity in surgical notes regarding the extent of the wound

Specialty Focus

Medical Specialties

Trauma Surgery

Documentation Requirements

Detailed operative reports, including descriptions of the wound, associated injuries, and surgical interventions performed.

Common Clinical Scenarios

Management of penetrating trauma, rib fractures, and complications such as pneumothorax or hemothorax.

Billing Considerations

Ensure that all associated injuries are documented to support the use of multiple codes.

Emergency Medicine

Documentation Requirements

Thorough initial assessment notes, including vital signs, mechanism of injury, and any immediate interventions performed.

Common Clinical Scenarios

Initial evaluation and stabilization of patients with thoracic trauma.

Billing Considerations

Accurate documentation of the patient's condition upon arrival and any changes during treatment.

Coding Guidelines

Inclusion Criteria

Use S21.40 When
  • According to ICD
  • 10 guidelines, this code should be used when the specific nature of the wound is not documented
  • Coders should ensure that the documentation supports the use of this code and that any associated injuries are coded appropriately

Exclusion Criteria

Do NOT use S21.40 When
No specific exclusions found.

Related ICD-10 Codes

Related CPT Codes

32000CPT Code

Thoracentesis

Clinical Scenario

Used to drain fluid from the thoracic cavity in cases of hemothorax.

Documentation Requirements

Document the indication for the procedure and the amount of fluid drained.

Specialty Considerations

Ensure that the procedure is linked to the diagnosis of thoracic injury.

39000CPT Code

Thoracotomy

Clinical Scenario

Performed for surgical repair of an open thoracic wound.

Documentation Requirements

Detailed operative report outlining the procedure and findings.

Specialty Considerations

Accurate coding requires clear documentation of the surgical approach and any complications.

ICD-10 Impact

Diagnostic & Documentation Impact

Enhanced Specificity

ICD-10 Improvements

The transition to ICD-10 has allowed for more specific coding of thoracic injuries, improving the accuracy of data collection and reimbursement processes. S21.40 provides a framework for capturing unspecified open wounds, but coders must ensure that documentation supports the use of this code to avoid potential denials.

ICD-9 vs ICD-10

The transition to ICD-10 has allowed for more specific coding of thoracic injuries, improving the accuracy of data collection and reimbursement processes. S21.40 provides a framework for capturing unspecified open wounds, but coders must ensure that documentation supports the use of this code to avoid potential denials.

Reimbursement & Billing Impact

reimbursement processes. S21.40 provides a framework for capturing unspecified open wounds, but coders must ensure that documentation supports the use of this code to avoid potential denials.

Resources

Clinical References

  • •
    ICD-10-CM Official Guidelines for Coding and Reporting

Coding & Billing References

  • •
    ICD-10-CM Official Guidelines for Coding and Reporting

Frequently Asked Questions

What documentation is required to support the use of S21.40?

Documentation must include a detailed description of the wound, the mechanism of injury, any associated injuries, and the treatment provided. This ensures that the coding accurately reflects the patient's condition.

Can S21.40 be used for all types of thoracic injuries?

No, S21.40 is specific to open wounds of the back wall of the thorax with penetration into the thoracic cavity. Other types of injuries, such as closed wounds or injuries to other thoracic structures, require different codes.