ICD-10-CM 2027
ICD-10 code for trunk corrosion
From the official ICD-10-CM alphabetic index entry “Corrosion (injury) (acid) (caustic) (chemical) (lime) (external) (internal) › trunk”. Page updated September 29, 2026.
About coding trunk corrosion
The ICD-10-CM code for trunk corrosion is T21.40 (Corrosion of unspecified degree of trunk, unspecified site). The official index lists 8 more specific codes, so check the documentation for details such as type, cause, site or severity before settling on T21.40.
Within T21.4, choose T21.40 (unspecified site) only when documentation doesn't support a more specific option: chest wall (T21.41), abdominal wall (T21.42), upper back (T21.43), lower back (T21.44), buttock (T21.45), male genital region (T21.46), female genital region (T21.47) and other site of trunk (T21.49).
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 trunk corrosion codes (official index)
- abdominal wall
- anus
- axilla
- back
- breast
- buttock
- chest wall
- first degree T21.50 — Corrosion of first degree of trunk, unspecified site
- flank
- genital
- female
- male
- groin
- interscapular region
- labia
- lower back
- penis
- perineum
- female
- male
- scapular region
- scrotum
- second degree T21.60 — Corrosion of second degree of trunk, unspecified site
- shoulder
- specified site NEC T21.49 — Corrosion of unspecified degree of other site of trunk
- first degree T21.59 — Corrosion of first degree of other site of trunk
- second degree T21.69 — Corrosion of second degree of other site of trunk
- third degree T21.79 — Corrosion of third degree of other site of trunk
- testes
- third degree T21.70 — Corrosion of third degree of trunk, unspecified site
- upper back
- vagina T28.8 — Corrosion of internal genitourinary organs
- vulva
Common questions about trunk corrosion ICD-10 codes
What is the ICD-10 code for trunk corrosion?
- T21.40 — Corrosion of unspecified degree of trunk, unspecified site (a header code; report a more specific subcode). More specific codes apply when the documentation supports them: T21.50, T21.60, T21.49, T21.59 and others below.
What is the ICD-10 code for first degree trunk corrosion?
- T21.50 — Corrosion of first degree of trunk, unspecified site (header code; choose a more specific subcode).
What is the ICD-10 code for second degree trunk corrosion?
- T21.60 — Corrosion of second degree of trunk, unspecified site (header code; choose a more specific subcode).
What is the ICD-10 code for third degree trunk corrosion?
- T21.70 — Corrosion of third degree of trunk, unspecified site (header code; choose a more specific subcode).
What is the ICD-10 code for vagina trunk corrosion?
- T28.8 — Corrosion of internal genitourinary organs (header code; choose a more specific subcode).
Is T21.40 billable?
- No. T21.40 is a header code. Report one of its more specific subcodes instead.