T20.40
⚠ Non-billable (Header)Corrosion of unspecified degree of head, face, and neck, unspecified site
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.
⚠️ Excludes2
inheritedRules inherited from parent codes.
- • burn and corrosion of ear drum (T28.41, T28.91)
- • burn and corrosion of eye and adnexa (T26.-)
- • burn and corrosion of mouth and pharynx (T28.0)
📋 Code Instructions
inherited- • external cause code to identify place (Y92)
- • Code first: (T51-T65) to identify chemical and intent
Child Codes (3)
Clinical Description
ICD-10-CM code T20.40 represents corrosion of unspecified degree of head, face, and neck, unspecified site. 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 6-character code at the 5th level of specificity. There are 3 more specific child codes under T20.40.
Frequently Asked Questions
What is ICD-10 code T20.40?
ICD-10-CM code T20.40 is "Corrosion of unspecified degree of head, face, and neck, unspecified site". It belongs to the category: Injury, poisoning and certain other consequences of external causes (S00-T88).
Is T20.40 a billable ICD-10 code?
No, T20.40 is a non-billable header code. A more specific child code must be used for billing.
Can T20.40 be coded with other codes?
T20.40 has 3 Excludes2 note(s). These conditions can be coded together if both are documented in the patient record.
Related Codes in T20.4
Other codes in the same category that may be relevant for differential coding:
🧪 Validate Combinations
Add T20.40 to the Excludes Checker to validate against your full code list.
Open in Checker →Code Information
Data Source
CMS ICD-10-CM 2026 Tabular List
Updated October 1, 2025 (FY2026)