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T21.5

⚠ Non-billable (Header)

Corrosion of first degree of trunk

Injury, poisoning and certain other consequences of external causes (S00-T88)

⚠️ This is a category header code — not billable. Use a more specific child code below.

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⚠️ Excludes2

inherited

Rules inherited from parent codes.

T21
  • • burns and corrosion of axilla (T22.- with fifth character 4)
  • • burns and corrosion of scapular region (T22.- with fifth character 6)
  • • burns and corrosion of shoulder (T22.- with fifth character 5)

📋 Code Instructions

direct
  • • external cause code to identify place (Y92)
  • • Code first: (T51-T65) to identify chemical and intent

Child Codes (9)

T21.50Corrosion of first degree of trunk, unspecified siteT21.51Corrosion of first degree of chest wallT21.52Corrosion of first degree of abdominal wallT21.53Corrosion of first degree of upper backT21.54Corrosion of first degree of lower backT21.55Corrosion of first degree of buttockT21.56Corrosion of first degree of male genital regionT21.57Corrosion of first degree of female genital regionT21.59Corrosion of first degree of other site of trunk

Clinical Description

ICD-10-CM code T21.5 represents corrosion of first degree of trunk. This code falls under the Injury, poisoning and certain other consequences of external causes (S00-T88) classification. It is a non-billable category header code. A more specific child code from the list below must be used for billing and reimbursement purposes.

This is a 5-character code at the 4th level of specificity. There are 9 more specific child codes under T21.5.

Frequently Asked Questions

What is ICD-10 code T21.5?

ICD-10-CM code T21.5 is "Corrosion of first degree of trunk". It belongs to the category: Injury, poisoning and certain other consequences of external causes (S00-T88).

Is T21.5 a billable ICD-10 code?

No, T21.5 is a non-billable header code. A more specific child code must be used for billing.

Can T21.5 be coded with other codes?

T21.5 has 3 Excludes2 note(s). These conditions can be coded together if both are documented in the patient record.

Related Codes in T21

Other codes in the same category that may be relevant for differential coding:

T21.0Burn of unspecified degree of trunkT21.1Burn of first degree of trunkT21.2Burn of second degree of trunkT21.3Burn of third degree of trunkT21.4Corrosion of unspecified degree of trunkT21.6Corrosion of second degree of trunkT21.7Corrosion of third degree of trunk

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Code Information

CodeT21.5
BillableNo — Header code
ParentT21
CategoryInjury, poisoning and certain other consequences of external causes (S00-T88)
Excludes10 rule(s)
Excludes23 note(s)
Child codes9

Data Source

CMS ICD-10-CM 2026 Tabular List

Updated October 1, 2025 (FY2026)