ICD-10-CM 2027 diagnosis code

T24.73Corrosion of third degree of lower leg

Not billable — use a more specific codeRequires 7th character

T24.73 is a header code, so it can't be reported by itself. Choose one of the 3 more specific codes beneath it and add the required 7th character.

Code unchanged since ICD-10-CM took effect on October 1, 2015. Source: official FY2027 ICD-10-CM release from CDC/NCHS and CMS. Page updated September 29, 2026. About our data

About T24.73

T24.73 is the ICD-10-CM diagnosis code for corrosion of third degree of lower leg. It belongs to category T24 (burn and corrosion of lower limb, except ankle and foot), block T20-T25 (burns and corrosions of external body surface, specified by site) and chapter 19 (injury, poisoning and certain other consequences of external causes). It is a header code, so it can't be reported by itself; one of its 3 subcodes must be used instead.

Within T24.7 (corrosion of third degree of lower limb, except ankle and foot), T24.73 is specifically for corrosion of third degree of lower leg. Related codes cover unspecified site of lower limb, except ankle and foot (T24.70), thigh (T24.71), knee (T24.72) and multiple sites of lower limb, except ankle and foot (T24.79).

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.

7th character

The appropriate 7th character is to be added to each code from category T24

Ainitial encounter
Dsubsequent encounter
Ssequela

Notes that apply from higher levels

Instructions written at a parent level also apply to T24.73.

› From T24.7 Corrosion of third degree of lower limb, except ankle and foot

Code first

(T51-T65) to identify chemical and intent

Use additional code

external cause code to identify place (Y92)

› From T24 Burn and corrosion of lower limb, except ankle and foot

Excludes2

burn and corrosion of ankle and foot (T25.-)
burn and corrosion of hip region (T21.-)

Broader instructions also apply from T20-T25 Burns and corrosions of external body surface, specified by site and Chapter 19: Injury, poisoning and certain other consequences of external causes.

Code history

2016
2017
2018
2019
2020
2021
2022
2023
2024
2025
2026
2027

FY2016 (effective 10/1/2015): Added (first year of ICD-10-CM)
No changes since FY2016.

Common questions about T24.73

Is T24.73 billable?: No. T24.73 is a header code. Report one of its more specific subcodes instead.