2021 ICD-10-CM Code S21.309A

Unspecified open wound of unspecified front wall of thorax with penetration into thoracic cavity, initial encounter

Version 2021

Valid for Submission

S21.309A is a billable diagnosis code used to specify a medical diagnosis of unspecified open wound of unspecified front wall of thorax with penetration into thoracic cavity, initial encounter. The code S21.309A is valid during the fiscal year 2021 from October 01, 2020 through September 30, 2021 for the submission of HIPAA-covered transactions.

The ICD-10-CM code S21.309A might also be used to specify conditions or terms like crushed chest with open wound into thoracic cavity, crushing injury of chest or gunshot wound of chest.

S21.309A is an initial encounter code, includes a 7th character and should be used while the patient is receiving active treatment for a condition like unspecified open wound of unspecified front wall of thorax with penetration into thoracic cavity. According to ICD-10-CM Guidelines an "initial encounter" doesn't necessarily means "initial visit". The 7th character should be used when the patient is undergoing active treatment regardless if new or different providers saw the patient over the course of a treatment. The appropriate 7th character codes should also be used even if the patient delayed seeking treatment for a condition.

Unspecified diagnosis codes like S21.309A are acceptable when clinical information is unknown or not available about a particular condition. Although a more specific code is preferable, unspecified codes should be used when such codes most accurately reflect what is known about a patient's condition. Specific diagnosis codes should not be used if not supported by the patient's medical record.

ICD-10:S21.309A
Short Description:Unsp opn wnd unsp front wall of thrx w penet thor cav, init
Long Description:Unspecified open wound of unspecified front wall of thorax with penetration into thoracic cavity, initial encounter

Code Classification

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:

Approximate Synonyms

The following clinical terms are approximate synonyms or lay terms that might be used to identify the correct diagnosis code:

Convert S21.309A to ICD-9 Code

The General Equivalency Mapping (GEM) crosswalk indicates an approximate mapping between the ICD-10 code S21.309A its ICD-9 equivalent. The approximate mapping means there is not an exact match between the ICD-10 code and the ICD-9 code and the mapped code is not a precise representation of the original code.

Information for Patients


Chest Injuries and Disorders

The chest is the part of the body between your neck and your abdomen. It includes the ribs and breastbone. Inside your chest are several organs, including the heart, lungs, and esophagus. The pleura, a large thin sheet of tissue, lines the inside of the chest cavity.

Chest injuries and disorders include


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Wounds and Injuries

Also called: Traumatic 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


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Code History

  • 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 (First year ICD-10-CM implemented into the HIPAA code set)