Open wound of thorax (S21) ICD-10-CM

About the S21 Code Range

The S21 ICD-10 codes classify various types of open wounds to the thorax, including the breast, front and back chest walls, and specify whether these injuries penetrate the thoracic cavity. These codes capture detailed injury types such as lacerations, puncture wounds, and bites, with and without foreign bodies, as well as specify laterality and encounter status.

This section includes codes like S21.0 for open wounds of the breast—often referred to as lacerations or puncture wounds of the right or left breast—and extends to complex trauma involving the chest wall. For example, “stab wound of chest” and “open bite of thorax” are synonymous with specific laceration and bite wound codes within this group, such as S21.011 or S21.051. Codes also differentiate between wounds with foreign bodies, such as glass or fishing hooks, and without. Furthermore, distinctions exist for wounds penetrating the thoracic cavity versus those limited to chest wall tissues, aiding medical coders in precise documentation. Additionally, seventh-character extensions mark whether the treatment is for an initial encounter, subsequent encounter, or sequela (complications or residuals). Overall, the ICD-10 code for open wound of thorax enables clear classification of chest injuries by location, wound type, presence of foreign objects, and treatment phase, supporting accurate medical reporting and patient management.