S21.10 Unspecified open wound of front wall of thorax without penetration into thoracic cavity

ICD-10-CM S21.10: Unspecified open wound of front wall of thorax without penetration into thoracic cavity

ICD-10-CM code S21.10 designates an unspecified open wound of the front wall of the thorax that does not penetrate into the thoracic cavity. The terminology record classifies this diagnosis as an active concept under the broader parent category of front wall thorax open wounds, functioning as a specific injury or poisoning designation. 1 4

Plain-language overview

This diagnosis code identifies an open wound located on the front portion of the chest wall that has not broken through into the internal thoracic cavity, though the specific clinical details of the injury remain unspecified. 1

What this code represents

The official display label for S21.10 is Unspecified open wound of front wall of thorax without penetration into thoracic cavity, and the concept carries the semantic type of Injury or Poisoning. 1

Within the ICD-10-CM hierarchy, S21.10 is a child concept falling under the parent code S21.1, which covers open wounds of the front wall of the thorax without penetration into the thoracic cavity. 1

Coding details

The S21.10 terminology record indicates that this active code has no narrower child concepts, meaning it currently stands as a terminal endpoint within this specific branch of the classification tree. 1

The code tree distinguishes S21.10 from other nearby front wall thorax injuries, such as S21.30 for wounds with cavity penetration and S21.159 for open bites without cavity penetration. 5

Documentation considerations

The terminology record for S21.10 includes a published abbreviation, Unsp opn wnd front wall of thorax w/o penet thoracic cavity, which mirrors the full official display label for this injury concept. 1

Coverage and utilization context

Medicare billing and coding articles concerning computerized axial tomography and wound care reference related codes for unspecified open wounds of the front wall of the thorax, including laterality and sequela variations. 2 3

What the sources add

While the terminology authority defines S21.10 as a single unspecified code, Medicare billing articles reference more specific laterality and encounter variations like S21.102A for right front wall wounds. 1 2

A separate terminology explorer interface confirms the S21.10 code and its official description, providing an additional official domain that mirrors the primary vocabulary services record for this injury. 4

Sources

1. ICD-10-CM S21.10 terminology record — National Cancer Institute Enterprise Vocabulary Services; accessed 2026-07-27.
2. Article - Billing and Coding: Computerized Axial Tomography (CT), Thorax (A56580) — cms.gov; accessed 2026-07-27.
3. Article - Billing and Coding: Wound and Ulcer Care (A58565) — cms.gov; accessed 2026-07-27.
4. EVS Explore — evsexplore.semantics.cancer.gov; accessed 2026-07-27.
5. ICD-10-CM 2024 | S29 - Other and unspecified injuries of thorax — unboundmedicine.com; accessed 2026-07-27.