W94.21XA – Exposure to reduction in atmospheric pressure while surfacing from deep-water diving, initial encounter

ICD-10-CM 2027 diagnosis code · Exposure to electric current, radiation and extreme ambient air temperature and pressure

Billable code

ICD-10-CM code W94.21XA

Code: W94.21XA (claims format: W9421XA)
Description: Exposure to reduction in atmospheric pressure while surfacing from deep-water diving, initial encounter
Short description: Expsr to rdct in atmos pressr wh surfc fr dp-watr div, init
Billable: Yes – valid for HIPAA-covered transactions
Valid for: Dates of service October 1, 2026 – September 30, 2027 (FY2027)
Chapter: 20. External causes of morbidity (V00-Y99)
Block: W85-W99 Exposure to electric current, radiation and extreme ambient air temperature and pressure
Parent codes: W94 › W94.2 › W94.21

7th character values

Codes in this category need a 7th character to describe the encounter or episode of care.

Character	Meaning
`A`	initial encounter
`D`	subsequent encounter
`S`	sequela

Notes inherited from parent codes

Instructional notes at a category or block level apply to every code below it.

W94 – Exposure to high and low air pressure and changes in air pressure

7th character note:

The appropriate 7th character is to be added to each code from category W94

Block W85-W99

Excludes1 (not coded here):

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)

Related codes in W94.21

Frequently asked questions

What is ICD-10 code W94.21XA?

W94.21XA is the ICD-10-CM code for exposure to reduction in atmospheric pressure while surfacing from deep-water diving, initial encounter, in the block W85-W99 (Exposure to electric current, radiation and extreme ambient air temperature and pressure).

Is W94.21XA a billable code?

Yes. W94.21XA is a billable/specific code that can be used to indicate a diagnosis for reimbursement purposes.

What category does W94.21XA belong to?

It belongs to category W94 – Exposure to high and low air pressure and changes in air pressure.

Source: CDC/NCHS ICD-10-CM FY2027 code files, tabular list and index. Reference only – code assignment must follow the official ICD-10-CM guidelines and documentation in the medical record.