ICD-10-CM 2027
ICD-10 code for head corrosion
Corrosion of unspecified degree of head, face, and neck, unspecified site
From the official ICD-10-CM alphabetic index entry “Corrosion (injury) (acid) (caustic) (chemical) (lime) (external) (internal) › head (and face) (and neck)”. Page updated September 29, 2026.
About coding head corrosion
The ICD-10-CM code for head corrosion is T20.40 (Corrosion of unspecified degree of head, face, and neck, unspecified site). The official index lists 7 more specific codes, so check the documentation for details such as type, cause, site or severity before settling on T20.40.
Within T20.4, choose T20.40 (unspecified site) only when documentation doesn't support a more specific option: ear [any part, except ear drum] (T20.41), lip(s) (T20.42), chin (T20.43), nose (septum) (T20.44), scalp [any part] (T20.45), forehead and cheek (T20.46), neck (T20.47) and multiple sites of head, face, and neck (T20.49).
Codes in this range require a 7th character: A for initial encounter, D for subsequent encounter and S for sequela. Use placeholder "X" characters to fill any empty positions before the 7th character.
It has been part of ICD-10-CM since the code set took effect on October 1, 2015 and hasn't changed since.
More specific head corrosion codes (official index)
- cheek
- chin
- ear
- eye (s) only
- first degree T20.50 — Corrosion of first degree of head, face, and neck, unspecified site
- forehead
- lip
- multiple sites T20.49 — Corrosion of unspecified degree of multiple sites of head, face, and neck
- first degree T20.59 — Corrosion of first degree of multiple sites of head, face, and neck
- second degree T20.69 — Corrosion of second degree of multiple sites of head, face, and neck
- third degree T20.79 — Corrosion of third degree of multiple sites of head, face, and neck
- neck
- nose
- scalp
- second degree T20.60 — Corrosion of second degree of head, face, and neck, unspecified site
- third degree T20.70 — Corrosion of third degree of head, face, and neck, unspecified site
Common questions about head corrosion ICD-10 codes
What is the ICD-10 code for head corrosion?
- T20.40 — Corrosion of unspecified degree of head, face, and neck, unspecified site (a header code; report a more specific subcode). More specific codes apply when the documentation supports them: T20.50, T20.49, T20.59, T20.69 and others below.
What is the ICD-10 code for first degree head corrosion?
- T20.50 — Corrosion of first degree of head, face, and neck, unspecified site (header code; choose a more specific subcode).
What is the ICD-10 code for multiple sites head corrosion?
- T20.49 — Corrosion of unspecified degree of multiple sites of head, face, and neck (header code; choose a more specific subcode).
What is the ICD-10 code for second degree head corrosion?
- T20.60 — Corrosion of second degree of head, face, and neck, unspecified site (header code; choose a more specific subcode).
What is the ICD-10 code for third degree head corrosion?
- T20.70 — Corrosion of third degree of head, face, and neck, unspecified site (header code; choose a more specific subcode).
Is T20.40 billable?
- No. T20.40 is a header code. Report one of its more specific subcodes instead.