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ICD-10-CM 2027 diagnosis code

X37.4Tidalwave

Not billable — use a more specific codeRequires 7th character

X37.4 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 X37.4

X37.4 is the ICD-10-CM diagnosis code for Tidalwave. It belongs to category X37 (cataclysmic storm), block X30-X39 (exposure to forces of nature) and chapter 20 (external causes of morbidity). It is a header code, so it can't be reported by itself; one of its 3 subcodes must be used instead.

Within X37 (cataclysmic storm), X37.4 is specifically for Tidalwave. Related codes cover Hurricane (X37.0), Tornado (X37.1), Blizzard (snow)(ice) (X37.2), dust storm (X37.3), other cataclysmic storms (X37.8) and unspecified cataclysmic storm (X37.9).

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 X37

  • Ainitial encounter
  • Dsubsequent encounter
  • Ssequela

Notes that apply from higher levels

Instructions written at a parent level also apply to X37.4.

Broader instructions also apply from Chapter 20: External causes of morbidity.

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 X37.4

Is X37.4 billable?

No. X37.4 is a header code. Report one of its more specific subcodes instead.