Corrosion of second degree of unspecified toe(s) (nail)

Not billableICD-10-CM diagnosis code.

This code exists but cannot be submitted on its own. It groups the more specific codes beneath it.

A category header for its whole life, FY2016 onwards. It has never been valid for submission on its own.

Submit one of these 3 more specific codes instead:

T25.639A Corrosion of second degree of unspecified toe(s) (nail), initial encounter
T25.639D Corrosion of second degree of unspecified toe(s) (nail), subsequent encounter
T25.639S Corrosion of second degree of unspecified toe(s) (nail), sequela

This code requires a seventh character. See the rule below.

What has happened to this code

Every change the publisher made, from 2014 to now. Entries marked draft are from the pre-implementation releases: ICD-10 took effect on 1 October 2015, so nothing before FY2016 was ever valid on a claim.

FY2014 Added to the draft code set draft Corrosion of second degree of unspecified toe(s) (nail)

Official coding rules

Published by CDC for FY2027. A rule attached to a category binds every code beneath it, so the rules inherited from this code's ancestors are shown with the code they come from.

Inherited from T25 Burn and corrosion of ankle and foot

Seventh character required

The appropriate 7th character is to be added to each code from category T25

Inherited from the T20-T25 section Burns and corrosions of external body surface, specified by site (T20-T25)

Use additional code

code from category T31 or T32 to identify extent of body surface involved

Includes

burns and corrosions of first degree [erythema]
burns and corrosions of second degree [blisters][epidermal loss]
burns and corrosions of third degree [deep necrosis of underlying tissue] [full- thickness skin loss]

How CDC's index refers to this code

Wording from the official alphabetic index. Much of it appears nowhere in the code description, which is why a search for the everyday phrase so often finds nothing.

Corrosion > toe > second degree

Codes in the same group

Code	Description	Status
T25.631	Corrosion of second degree of right toe(s) (nail)	Not billable
T25.632	Corrosion of second degree of left toe(s) (nail)	Not billable