ICD-10-CM 2027
ICD-10 code for toe corrosion
Corrosion of unspecified degree of unspecified toe(s) (nail)
From the official ICD-10-CM alphabetic index entry “Corrosion (injury) (acid) (caustic) (chemical) (lime) (external) (internal) › toe”. Page updated September 29, 2026.
About coding toe corrosion
The ICD-10-CM code for toe corrosion is T25.439 (Corrosion of unspecified degree of unspecified toe(s) (nail)). The official index lists 11 more specific codes, so check the documentation for details such as type, cause, site or severity before settling on T25.439.
Within T25.43, choose T25.439 (unspecified toe(s) (nail)) only when documentation doesn't support a more specific option: right toe(s) (nail) (T25.431) and left toe(s) (nail) (T25.432).
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 toe corrosion codes (official index)
- first degree T25.539 — Corrosion of first degree of unspecified toe(s) (nail)
- left T25.432 — Corrosion of unspecified degree of left toe(s) (nail)
- first degree T25.532 — Corrosion of first degree of left toe(s) (nail)
- second degree T25.632 — Corrosion of second degree of left toe(s) (nail)
- third degree T25.732 — Corrosion of third degree of left toe(s) (nail)
- right T25.431 — Corrosion of unspecified degree of right toe(s) (nail)
- first degree T25.531 — Corrosion of first degree of right toe(s) (nail)
- second degree T25.631 — Corrosion of second degree of right toe(s) (nail)
- third degree T25.731 — Corrosion of third degree of right toe(s) (nail)
- second degree T25.639 — Corrosion of second degree of unspecified toe(s) (nail)
- third degree T25.739 — Corrosion of third degree of unspecified toe(s) (nail)
Common questions about toe corrosion ICD-10 codes
What is the ICD-10 code for toe corrosion?
- T25.439 — Corrosion of unspecified degree of unspecified toe(s) (nail) (a header code; report a more specific subcode). More specific codes apply when the documentation supports them: T25.539, T25.432, T25.532, T25.632 and others below.
What is the ICD-10 code for first degree toe corrosion?
- T25.539 — Corrosion of first degree of unspecified toe(s) (nail) (header code; choose a more specific subcode).
What is the ICD-10 code for left toe corrosion?
- T25.432 — Corrosion of unspecified degree of left toe(s) (nail) (header code; choose a more specific subcode).
What is the ICD-10 code for right toe corrosion?
- T25.431 — Corrosion of unspecified degree of right toe(s) (nail) (header code; choose a more specific subcode).
What is the ICD-10 code for second degree toe corrosion?
- T25.639 — Corrosion of second degree of unspecified toe(s) (nail) (header code; choose a more specific subcode).
What is the ICD-10 code for third degree toe corrosion?
- T25.739 — Corrosion of third degree of unspecified toe(s) (nail) (header code; choose a more specific subcode).
Is T25.439 billable?
- No. T25.439 is a header code. Report one of its more specific subcodes instead.