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ICD-10/S21.10

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

Billing Status: NO. This is a clinician non-billable / parent hierarchy grouping in the ICD-10-CM system.

Code Set: Valid FY2026 and FY2027. FY2026 took effect October 1, 2025.

Official Registry Overview & Definition

Unspecified open wound of front wall of thorax without penetration into thoracic cavity is a non-billable ICD-10-CM category code (S21.10). A more specific billable subcode must be selected for claims submission.

Official Tabular Instructional Notes

Sequencing, inclusion, and exclusion notes published for S21.10 in the official ICD-10-CM tabular list.

Includes

Conditions the official ICD-10-CM tabular list includes under this code.

  • injuries of breast
  • injuries of chest (wall)
  • injuries of interscapular area

Excludes1 — Not Coded Here

Conditions that can never be reported with this code; the two are mutually exclusive.

  • traumatic amputation (partial) of thorax (S28.1)

Excludes2 — Not Included Here

Conditions not covered by this code, but which may be reported alongside it when both are present.

  • burns and corrosions (T20-T32)
  • effects of foreign body in bronchus (T17.5)
  • effects of foreign body in esophagus (T18.1)
  • effects of foreign body in lung (T17.8)
  • effects of foreign body in trachea (T17.4)
  • frostbite (T33-T34)
  • injuries of axilla
  • injuries of clavicle
  • injuries of scapular region
  • injuries of shoulder
  • insect bite or sting, venomous (T63.4)

Code Also

Additional codes that may be required to fully describe the encounter.

  • any associated injury, such as:
  • injury of heart (S26.-)
  • injury of intrathoracic organs (S27.-)
  • rib fracture (S22.3-, S22.4-)
  • spinal cord injury (S24.0-, S24.1-)
  • traumatic hemopneumothorax (S27.3)
  • traumatic hemothorax (S27.1)
  • traumatic pneumothorax (S27.0)
  • wound infection

Frequently Asked Questions (FAQ) & Clinical Guidance

Can S21.10 be billed directly?

No. S21.10 (Unspecified open wound of front wall of thorax without penetration into thoracic cavity) is a non-billable ICD-10-CM category code. A more specific billable subcode must be selected based on clinical documentation.

Does S21.10 require a 7th character?

Yes. The appropriate 7th character is to be added to each code from category S21.

Nearest Codes in This Family

Official ICD-10-CM classifications closest to S21.10 in its code family, with their registry titles.

  • S21.059 — Open bite of unspecified breast
  • S21.059A — Open bite of unspecified breast, initial encounter
  • S21.059D — Open bite of unspecified breast, subsequent encounter
  • S21.059S — Open bite of unspecified breast, sequela
  • S21.1 — Open wound of front wall of thorax without penetration into thoracic cavity
  • S21.101 — Unspecified open wound of right front wall of thorax without penetration into thoracic cavity
  • S21.101A — Unspecified open wound of right front wall of thorax without penetration into thoracic cavity, initial encounter
  • S21.101D — Unspecified open wound of right front wall of thorax without penetration into thoracic cavity, subsequent encounter
  • S21.101S — Unspecified open wound of right front wall of thorax without penetration into thoracic cavity, sequela
  • S21.102 — Unspecified open wound of left front wall of thorax without penetration into thoracic cavity

View all codes in the S21 family