2027 ICD-10-CM Diagnosis Code W94Exposure to high and low air pressure and changes in air pressure

ICD-10-CM Codes›V01–Y99›W85-W99›W94

ICD-10-CM W94
CMSSource: CMS FY 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

W94 is a non-billable ICD-10-CM category code for exposure to high and low air pressure and changes in air pressure, so it cannot be submitted on claims. Use a more specific code from this category instead, such as W94.0XXA, W94.0XXD, W94.0XXS, and W94.11XA.

Code Identity

ICD-10-CM Code
W94
Billable Status
No — Non-Billable Category
Code Describes
Exposure to high and low air pressure and changes in air pressure
Short Description
Expsr to high and low air pressr and changes in air pressure
Chapter
W85-W99
Exposure to electric current, radiation and extreme ambient air temperature and pressure

Code Classification

ChapterV01–Y99External causes of morbidity and mortality
SectionW85-W99Exposure to electric current, radiation and extreme ambient air temperature and pressure
CategoryW94Exposure to high and low air pressure and changes in air pressure
This CodeW94Exposure to high and low air pressure and changes in air pressure

Specific Coding for Expsr to high and low air pressr and changes in air pressureOverview

Non-specific codes like W94 require more characters. Use one of these billable codes instead:

  • W94.0 for Exposure to prolonged high air pressure

  • W94.1 for Exposure to prolonged low air pressure

  • W94.11 for Exposure to residence or prolonged visit at high altitude

  • W94.12 for Exposure to other prolonged low air pressure

  • W94.2 for Exposure to rapid changes in air pressure during ascent

  • W94.21 for Exposure to reduction in atmospheric pressure while surfacing from deep-water diving

  • W94.22 for Exposure to reduction in atmospheric pressure while surfacing from underground

  • W94.23 for Exposure to sudden change in air pressure in aircraft during ascent

  • W94.29 for Exposure to other rapid changes in air pressure during ascent

  • W94.3 for Exposure to rapid changes in air pressure during descent

  • W94.31 for Exposure to sudden change in air pressure in aircraft during descent

  • W94.32 for Exposure to high air pressure from rapid descent in water

  • W94.39 for Exposure to other rapid changes in air pressure during descent

Instructional NotesGuidance

Instructions from the official ICD-10-CM Tabular List that apply to W94: its own notes plus those printed at block W85-W99 and Chapter 20. A note printed at a category, block or chapter applies to every code under it.

Excludes1

Not coded here: the excluded code is never reported together with this one, unless the two conditions are unrelated.

From Block W85-W99 Exposure to electric current, radiation and extreme ambient air temperature and pressure applies to 99 codes
  • exposure to:
  • failure in dosage of radiation or temperature during surgical and medical care (Y63.2-Y63.5)
  • lightning (T75.0-)
  • natural cold (X31)
  • natural heat (X30)
  • natural radiation NOS (X39)
  • radiological procedure and radiotherapy (Y84.2)
  • sunlight (X32)

Notes

General instructions on how these codes are used.

From Chapter 20 (V00-Y99) External causes of morbidity and mortality applies to 7,461 codes
  • This chapter permits the classification of environmental events and circumstances as the cause of injury, and other adverse effects. Where a code from this section is applicable, it is intended that it shall be used secondary to a code from another chapter of the Classification indicating the nature of the condition. Most often, the condition will be classifiable to Chapter 19, Injury, poisoning and certain other consequences of external causes (S00-T88). Other conditions that may be stated to be due to external causes are classified in Chapters I to XVIII. For these conditions, codes from Chapter 20 should be used to provide additional information as to the cause of the condition.

7th Character

Every code in the category takes a 7th character from the listed values, with the placeholder X filling any empty positions before it.

  • The appropriate 7th character is to be added to each code from category W94
Values for category W94 Encounter: Initial, Subsequent, Sequela
  • Ainitial encounter
  • Dsubsequent encounter
  • Ssequela

Source: CMS ICD-10-CM Tabular List. How to read instructional notes.

Referenced in Other NotesGuidance

Instructional notes printed at other codes that name W94, its category, or a range that includes it.

Excludes1 2

These codes carry an Excludes1 note naming W94: they are not reported together with it, unless the two conditions are unrelated.

  • V97.8 Other air transport accidents, not elsewhere classified
    exposure to changes in air pressure during ascent or descent (W94.-)
  • W16 Fall, jump or diving into water
    effects of air pressure from diving (W94.-)

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2026No changes
FY 2027CurrentCurrent code set, no changesEffective October 1, 2026 through September 30, 2027.

Questions About W94Overview

What is the ICD-10 code for exposure to high and low air pressure and changes in air pressure?

W94 is the ICD-10-CM category for exposure to high and low air pressure and changes in air pressure, but it is a non-billable header: claims need a more specific code from this category, listed on this page.

Is W94 a billable code?

No. This is a category header that groups the codes for exposure to high and low air pressure and changes in air pressure, and headers cannot be submitted on claims. Claims for exposure to high and low air pressure and changes in air pressure need a more specific code from this category, such as W94.0XXA, W94.0XXD, and W94.0XXS.

Can W94 be reported with a code from T75.0?

Not as a rule. The Excludes1 note at block W85-W99, which applies to W94, lists "lightning (T75.0-)". An Excludes1 note means the excluded code is never reported together with this one; the only exception is when the two conditions are unrelated to each other (Official Guidelines, Section I.A.12.a).