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ICD-10-CM 2027 diagnosis code

T54.3Toxic effects of corrosive alkalis and alkali-like substances

Not billable — use a more specific codeRequires 7th character

T54.3 is a header code, so it can't be reported by itself. Choose one of the 1 more specific codes beneath it and add the required 7th character.Short description: Toxic effects of corrosive alkalis and alk-like substances

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 T54.3

T54.3 is the ICD-10-CM diagnosis code for toxic effects of corrosive alkalis and alkali-like substances. It belongs to category T54 (toxic effect of corrosive substances), block T51-T65 (toxic effects of substances chiefly nonmedicinal as to source) 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 1 subcodes must be used instead.

Within T54 (toxic effect of corrosive substances), T54.3 is specifically for toxic effects of corrosive alkalis and alkali-like substances. Related codes cover phenol and phenol homologues (T54.0), other corrosive organic compounds (T54.1), corrosive acids and acid-like substances (T54.2) and unspecified corrosive substance (T54.9).

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 T54

  • Ainitial encounter
  • Dsubsequent encounter
  • Ssequela

Coding notes

Applicable toConditions and synonyms classified to this code
  • Toxic effects of potassium hydroxide
  • Toxic effects of sodium hydroxide

Notes that apply from higher levels

Instructions written at a parent level also apply to T54.3.

Broader instructions also apply from T51-T65 Toxic effects of substances chiefly nonmedicinal as to source and Chapter 19: Injury, poisoning and certain other consequences of external causes.

Code history

  1. 2016
  2. 2017
  3. 2018
  4. 2019
  5. 2020
  6. 2021
  7. 2022
  8. 2023
  9. 2024
  10. 2025
  11. 2026
  12. 2027
  • FY2016 (effective 10/1/2015): Added (first year of ICD-10-CM)
  • No changes since FY2016.

Common questions about T54.3

Is T54.3 billable?

No. T54.3 is a header code. Report one of its more specific subcodes instead.