W94.21XA ICD-10-CM Code: Exposure to reduction in atmospheric pressure while surfacing from deep-water diving, initial encounter
Billing Status: YES. This is a valid, specific, and billable ICD-10-CM reference.
Code Set: Valid FY2026 and FY2027. FY2026 took effect October 1, 2025.
Official Registry Overview & Definition
Exposure to reduction in atmospheric pressure while surfacing from deep-water diving, initial encounter is a billable ICD-10-CM diagnosis code (W94.21A).
Official Tabular Instructional Notes
Sequencing, inclusion, and exclusion notes published for W94.21XA in the official ICD-10-CM tabular list.
Excludes1 — Not Coded Here
Conditions that can never be reported with this code; the two are mutually exclusive.
- 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)
Frequently Asked Questions (FAQ) & Clinical Guidance
Does W94.21XA require a 7th character?
Yes. The appropriate 7th character is to be added to each code from category W94.
Nearest Codes in This Family
Official ICD-10-CM classifications closest to W94.21XA in its code family, with their registry titles.
- W94.12XA — Exposure to other prolonged low air pressure, initial encounter
- W94.12XD — Exposure to other prolonged low air pressure, subsequent encounter
- W94.12XS — Exposure to other prolonged low air pressure, sequela
- W94.2 — Exposure to rapid changes in air pressure during ascent
- W94.21 — Exposure to reduction in atmospheric pressure while surfacing from deep-water diving
- W94.21XD — Exposure to reduction in atmospheric pressure while surfacing from deep-water diving, subsequent encounter
- W94.21XS — Exposure to reduction in atmospheric pressure while surfacing from deep-water diving, sequela
- W94.22 — Exposure to reduction in atmospheric pressure while surfacing from underground
- W94.22XA — Exposure to reduction in atmospheric pressure while surfacing from underground, initial encounter
- W94.22XD — Exposure to reduction in atmospheric pressure while surfacing from underground, subsequent encounter