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  6. 2024 ICD-10-CM Code S21.4
Version 2024
Non-Billable Code

2024 ICD-10-CM Diagnosis Code S21.4

Open wound of back wall of thorax with penetration into thoracic cavity

ICD-10-CM Code:
S21.4
ICD-10 Code for:
Open wound of back wall of thorax w penet thoracic cavity
Is Billable?
Not Valid for Submission
Code Navigator:

Code Classification

  • Injury, poisoning and certain other consequences of external causes
    (S00–T88)
    • Injuries to the thorax
      (S20-S29)
      • Open wound of thorax
        (S21)

S21.4 is a non-specific and non-billable diagnosis code code, consider using a code with a higher level of specificity for a diagnosis of open wound of back wall of thorax with penetration into thoracic cavity. The code is not specific and is NOT valid for the year 2024 for the submission of HIPAA-covered transactions. Category or Header define the heading of a category of codes that may be further subdivided by the use of 4th, 5th, 6th or 7th characters.

Specific Coding Applicable to Open wound of back wall of thorax w penet thoracic cavity

Non-specific codes like S21.4 require more digits to indicate the appropriate level of specificity. Consider using any of the following ICD-10-CM codes with a higher level of specificity when coding for open wound of back wall of thorax w penet thoracic cavity:

  • S21.40 for Unspecified open wound of back wall of thorax with penetration into thoracic cavity - NON-BILLABLE CODE

  • S21.401 for Unspecified open wound of right back wall of thorax with penetration into thoracic cavity - NON-BILLABLE CODE

  • Use S21.401A for initial encounter - BILLABLE CODE

  • Use S21.401D for subsequent encounter - BILLABLE CODE

  • Use S21.401S for sequela - BILLABLE CODE

  • S21.402 for Unspecified open wound of left back wall of thorax with penetration into thoracic cavity - NON-BILLABLE CODE

  • Use S21.402A for initial encounter - BILLABLE CODE

  • Use S21.402D for subsequent encounter - BILLABLE CODE

  • Use S21.402S for sequela - BILLABLE CODE

  • S21.409 for Unspecified open wound of unspecified back wall of thorax with penetration into thoracic cavity - NON-BILLABLE CODE

  • Use S21.409A for initial encounter - BILLABLE CODE

  • Use S21.409D for subsequent encounter - BILLABLE CODE

  • Use S21.409S for sequela - BILLABLE CODE

  • S21.41 for Laceration without foreign body of back wall of thorax with penetration into thoracic cavity - NON-BILLABLE CODE

  • S21.411 for Laceration without foreign body of right back wall of thorax with penetration into thoracic cavity - NON-BILLABLE CODE

  • Use S21.411A for initial encounter - BILLABLE CODE

  • Use S21.411D for subsequent encounter - BILLABLE CODE

  • Use S21.411S for sequela - BILLABLE CODE

  • S21.412 for Laceration without foreign body of left back wall of thorax with penetration into thoracic cavity - NON-BILLABLE CODE

  • Use S21.412A for initial encounter - BILLABLE CODE

  • Use S21.412D for subsequent encounter - BILLABLE CODE

  • Use S21.412S for sequela - BILLABLE CODE

  • S21.419 for Laceration without foreign body of unspecified back wall of thorax with penetration into thoracic cavity - NON-BILLABLE CODE

  • Use S21.419A for initial encounter - BILLABLE CODE

  • Use S21.419D for subsequent encounter - BILLABLE CODE

  • Use S21.419S for sequela - BILLABLE CODE

  • S21.42 for Laceration with foreign body of back wall of thorax with penetration into thoracic cavity - NON-BILLABLE CODE

  • S21.421 for Laceration with foreign body of right back wall of thorax with penetration into thoracic cavity - NON-BILLABLE CODE

  • Use S21.421A for initial encounter - BILLABLE CODE

  • Use S21.421D for subsequent encounter - BILLABLE CODE

  • Use S21.421S for sequela - BILLABLE CODE

  • S21.422 for Laceration with foreign body of left back wall of thorax with penetration into thoracic cavity - NON-BILLABLE CODE

  • Use S21.422A for initial encounter - BILLABLE CODE

  • Use S21.422D for subsequent encounter - BILLABLE CODE

  • Use S21.422S for sequela - BILLABLE CODE

  • S21.429 for Laceration with foreign body of unspecified back wall of thorax with penetration into thoracic cavity - NON-BILLABLE CODE

  • Use S21.429A for initial encounter - BILLABLE CODE

  • Use S21.429D for subsequent encounter - BILLABLE CODE

  • Use S21.429S for sequela - BILLABLE CODE

  • S21.43 for Puncture wound without foreign body of back wall of thorax with penetration into thoracic cavity - NON-BILLABLE CODE

  • S21.431 for Puncture wound without foreign body of right back wall of thorax with penetration into thoracic cavity - NON-BILLABLE CODE

  • Use S21.431A for initial encounter - BILLABLE CODE

  • Use S21.431D for subsequent encounter - BILLABLE CODE

  • Use S21.431S for sequela - BILLABLE CODE

  • S21.432 for Puncture wound without foreign body of left back wall of thorax with penetration into thoracic cavity - NON-BILLABLE CODE

  • Use S21.432A for initial encounter - BILLABLE CODE

  • Use S21.432D for subsequent encounter - BILLABLE CODE

  • Use S21.432S for sequela - BILLABLE CODE

  • S21.439 for Puncture wound without foreign body of unspecified back wall of thorax with penetration into thoracic cavity - NON-BILLABLE CODE

  • Use S21.439A for initial encounter - BILLABLE CODE

  • Use S21.439D for subsequent encounter - BILLABLE CODE

  • Use S21.439S for sequela - BILLABLE CODE

  • S21.44 for Puncture wound with foreign body of back wall of thorax with penetration into thoracic cavity - NON-BILLABLE CODE

  • S21.441 for Puncture wound with foreign body of right back wall of thorax with penetration into thoracic cavity - NON-BILLABLE CODE

  • Use S21.441A for initial encounter - BILLABLE CODE

  • Use S21.441D for subsequent encounter - BILLABLE CODE

  • Use S21.441S for sequela - BILLABLE CODE

  • S21.442 for Puncture wound with foreign body of left back wall of thorax with penetration into thoracic cavity - NON-BILLABLE CODE

  • Use S21.442A for initial encounter - BILLABLE CODE

  • Use S21.442D for subsequent encounter - BILLABLE CODE

  • Use S21.442S for sequela - BILLABLE CODE

  • S21.449 for Puncture wound with foreign body of unspecified back wall of thorax with penetration into thoracic cavity - NON-BILLABLE CODE

  • Use S21.449A for initial encounter - BILLABLE CODE

  • Use S21.449D for subsequent encounter - BILLABLE CODE

  • Use S21.449S for sequela - BILLABLE CODE

  • S21.45 for Open bite of back wall of thorax with penetration into thoracic cavity - NON-BILLABLE CODE

  • S21.451 for Open bite of right back wall of thorax with penetration into thoracic cavity - NON-BILLABLE CODE

  • Use S21.451A for initial encounter - BILLABLE CODE

  • Use S21.451D for subsequent encounter - BILLABLE CODE

  • Use S21.451S for sequela - BILLABLE CODE

  • S21.452 for Open bite of left back wall of thorax with penetration into thoracic cavity - NON-BILLABLE CODE

  • Use S21.452A for initial encounter - BILLABLE CODE

  • Use S21.452D for subsequent encounter - BILLABLE CODE

  • Use S21.452S for sequela - BILLABLE CODE

  • S21.459 for Open bite of unspecified back wall of thorax with penetration into thoracic cavity - NON-BILLABLE CODE

  • Use S21.459A for initial encounter - BILLABLE CODE

  • Use S21.459D for subsequent encounter - BILLABLE CODE

  • Use S21.459S for sequela - BILLABLE CODE

Coding Guidelines

The appropriate 7th character is to be added to each code from block Open wound of thorax (S21). Use the following options for the aplicable episode of care:

  • A - initial encounter
  • D - subsequent encounter
  • S - sequela

Patient Education


Back Injuries

Your back is made of bones, muscles, and other tissues extending from your neck to your pelvis. Back injuries can result from sports injuries, work around the house or in the garden, or a sudden jolt such as a car accident. The lower back is the most common site of back injuries and back pain. Common back injuries include :

  • Sprains and strains
  • Herniated disks
  • Fractured (broken) vertebrae

These injuries can cause pain and limit your movement. Treatments vary but might include medicines, icing, bed rest, physical therapy, or surgery. You might be able to prevent some back injuries by maintaining a healthy weight, lifting objects with your legs, and using lower-back support when you sit.


[Learn More in MedlinePlus]

Wounds and Injuries

An injury is damage to your body. It is a general term that refers to harm caused by accidents, falls, hits, weapons, and more. In the U.S., millions of people injure themselves every year. These injuries range from minor to life-threatening. Injuries can happen at work or play, indoors or outdoors, driving a car, or walking across the street.

Wounds are injuries that break the skin or other body tissues. They include cuts, scrapes, scratches, and punctured skin. They often happen because of an accident, but surgery, sutures, and stitches also cause wounds. Minor wounds usually aren't serious, but it is important to clean them. Serious and infected wounds may require first aid followed by a visit to your doctor. You should also seek attention if the wound is deep, you cannot close it yourself, you cannot stop the bleeding or get the dirt out, or it does not heal.

Other common types of injuries include:

  • Animal bites
  • Bruises
  • Burns
  • Dislocations
  • Electrical injuries
  • Fractures (broken bones)
  • Sprains and strains

[Learn More in MedlinePlus]

Code History

  • FY 2024 - No Change, effective from 10/1/2023 through 9/30/2024
  • FY 2023 - No Change, effective from 10/1/2022 through 9/30/2023
  • FY 2022 - No Change, effective from 10/1/2021 through 9/30/2022
  • FY 2021 - No Change, effective from 10/1/2020 through 9/30/2021
  • FY 2020 - No Change, effective from 10/1/2019 through 9/30/2020
  • FY 2019 - No Change, effective from 10/1/2018 through 9/30/2019
  • FY 2018 - No Change, effective from 10/1/2017 through 9/30/2018
  • FY 2017 - No Change, effective from 10/1/2016 through 9/30/2017
  • FY 2016 - New Code, effective from 10/1/2015 through 9/30/2016. This was the first year ICD-10-CM was implemented into the HIPAA code set.