T20.4

Header — not billable

Corrosion of unspecified degree of head, face, and neck

The ICD-10 code for corrosion of unspecified degree of head, face, and neck is T20.4.

T20.4 is a non-billable header code. It groups related conditions but cannot be used on its own for reimbursement — select one of the 9 more specific codes below.

Clinical notes

Code first

This code represents a manifestation of an underlying disease. Coding convention requires the underlying (etiology) code to be sequenced first, with this code listed second.

(T51-T65) to identify chemical and intent

Use additional code

This code represents an underlying condition. When a related manifestation is also present, coding convention calls for an additional code to be listed after this one.

external cause code to identify place (Y92)

Documentation support

General coding-documentation guidance — not a substitute for payer-specific requirements or professional coding judgment.

•This is a non-billable header code. Documentation must support a more specific child code before this diagnosis can be reported on a claim.
•This code describes an unspecified presentation. If the medical record documents a more specific detail (e.g. laterality, type, or affected site), a more specific sibling code should be used instead — see Related codes below.
•This code represents a manifestation. Documentation should identify the underlying condition, which must be coded first.
•If the associated manifestation or related condition noted above is also documented, an additional code should be reported alongside this one.
•As a general rule, code to the highest level of specificity supported by the documentation in the medical record.

T20.4

Clinical notes

Code first

Use additional code

Documentation support

Child codes under T20.4

Related codes in this category