W94.39XD ICD-10-CM Code: Exposure to other rapid changes in air pressure during descent, subsequent encounter
Billing Status: YES. This is a valid, specific, and billable ICD-10-CM reference.
Coding at a Glance
- 7th character
- Required — see the character table on this page
- Tabular directives
- 8 Excludes1
Coding instructions
Official Tabular Instructional Notes: the inclusion, exclusion and sequencing notes published for W94.39XD in the official ICD-10-CM tabular list, quoted as published.
Notes without a marker are published on W94.39XD itself; “inherited from” names the category or block whose note applies here.
Excludes1 — Not Coded Here
Conditions generally not reported together with this code (Excludes1) -- an error unless the two conditions are documented as unrelated to each other (ICD-10-CM Official Guidelines, Section I.A.12.a).
- exposure to:
- failure in dosage of radiation or temperature during surgical and medical care (Y63.2-Y63.5) Compare W94.39XD vs Y63.2 →
- lightning (T75.0-) Compare W94.39XD vs T75.0 →
- natural cold (X31) Compare W94.39XD vs X31 →
- natural heat (X30) Compare W94.39XD vs X30 →
- natural radiation NOS (X39) Compare W94.39XD vs X39 →
- radiological procedure and radiotherapy (Y84.2) Compare W94.39XD vs Y84.2 →
- sunlight (X32) Compare W94.39XD vs X32 →
Source: inherited from W85-W99
7th Character Guide
"The appropriate 7th character is to be added to each code from category W94"
- A — initial encounter
- D — subsequent encounter (this page’s code)
- S — sequela
How the encounter character is assigned. “Initial encounter” means the patient is receiving active treatment for the condition — it is not limited to the first visit, and a different or new provider giving active treatment still assigns it. “Subsequent encounter” covers care during the healing or recovery phase after active treatment. “Sequela” is for complications or conditions that arise as a direct result of the original condition.
ICD-10-CM Official Guidelines for Coding and Reporting, Section I.C.19.a (paraphrased by MedCoder).
Variant codes in this family
Character meanings are CMS's official 7th-character extensions for this family, as carried in each variant code's official description; variant codes are registry rows. The explanation of how the encounter character is assigned is MedCoder editorial, distinct from the official content above it.
Code Overview
MedCoder summary Summary composed by MedCoder from this code's official ICD-10-CM record. The tabular instructional notes themselves appear verbatim below.
Verify Before Coding
- Principal-diagnosis restriction. External cause of morbidity codes (V, W, X and Y) describe the circumstance that caused an injury, not the condition treated. The Medicare Code Editor rejects them as a principal diagnosis; sequence the injury or condition first and report this code as secondary.
From the code registry, the Medicare Code Editor, and the MS-DRG Definitions Manual. Check it against a full claim in Claim Check.
Relationships & Classification
Other codes that name W94.39XD or its code family, from the CMS ICD-10-CM tabular instructional notes. Tabular-note edges are stored at the code family level that carries each note.
Referenced by 2 Excludes1 notes: V97.8 — Other air transport accidents, not elsewhere classified (via W94.-), W16 — Fall, jump or diving into water (via W94.-).
These codes’ tabular lists mark this diagnosis as mutually exclusive — not reported together unless the conditions are documented as unrelated.
Clinical classification (AHRQ CCSR):EXT029 — External cause codes: subsequent encounter.
Clinical Classifications Software Refined (CCSR) for ICD-10-CM Diagnoses. Healthcare Cost and Utilization Project (HCUP), Agency for Healthcare Research and Quality.
Related Codes
Same clinical category (CCSR)
AHRQ's Clinical Classifications Software groups these diagnoses under the same clinical category (External cause codes: subsequent encounter).
Contextual Map
Every relationship of W94.39XD in one view: hierarchy, official tabular instructions in both directions, clinical classification, risk adjustment, MS-DRG participation, index terms and change history — each edge carrying the CMS source it derives from.
Run W94.39XD with these 2 related codes in Claim Check
Hierarchy
- V00-Y99 — Chapter 20: External Causes of Morbidity (V00-Y99) (V00-Y99)[Hierarchy]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
- W00-X58 — Other external causes of accidental injury[Hierarchy]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
- W85-W99 — Exposure to electric current, radiation and extreme ambient air temperature and pressure[Hierarchy]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
Referenced by Excludes1 notes
- V97.8 — Other air transport accidents, not elsewhere classified[Excludes1](via W94.-): “exposure to changes in air pressure during ascent or descent (W94.-)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
- W16 — Fall, jump or diving into water[Excludes1](via W94.-): “effects of air pressure from diving (W94.-)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
Clinical classification (CCSR)
- EXT029 — External cause codes: subsequent encounter[CCSR]— AHRQ CCSR for ICD-10-CM Diagnoses (HCUP)
Nearest codes (40)
- W94 — Exposure to high and low air pressure and changes in air pressure[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
- W94.0XXD — Exposure to prolonged high air pressure, subsequent encounter[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
- W94.0XXS — Exposure to prolonged high air pressure, sequela[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
- W94.1 — Exposure to prolonged low air pressure[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
- W94.11 — Exposure to residence or prolonged visit at high altitude[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
- W94.11XA — Exposure to residence or prolonged visit at high altitude, initial encounter[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
- W94.11XD — Exposure to residence or prolonged visit at high altitude, subsequent encounter[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
- W94.11XS — Exposure to residence or prolonged visit at high altitude, sequela[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
- and 32 more
Change history
- FY2016 — In the code set at ICD-10-CM adoption [Change history]— CMS release files (code change ledger) · icd10cm-fy2016
Common coding questions
Does W94.39XD require a 7th character?
Yes. The appropriate 7th character is to be added to each code from category W94.
Sources for this page
Codes, titles, notes, index terms and mappings on this page are transcribed from the datasets below. Relationships MedCoder computed and text MedCoder wrote are labelled where they appear.
- Code, title, tabular notes and index terms Official source data
- CMS/CDC ICD-10-CM FY2026 tabular list, index and tables, effective October 1, 2025 Release, file and checksum · Publisher’s page
- Claim edits Official source data
- CMS Definitions of Medicare Code Edits — v43.1 (April 2026) Release, file and checksum · Publisher’s page
- Change history and date-of-service validity Official source data
- CMS ICD-10-CM release addenda, ingested release by release into the change ledger Release, file and checksum · Publisher’s page
- Comparisons, relationships and the contextual map MedCoder structured relationship
- Computed by MedCoder from the tabular notes and tables above; every derived relationship is marked as derived where it appears
- Summary and FAQ answers MedCoder explanation
- Written by MedCoder to explain the sources above: drafted with AI assistance, checked by a person against the release files, and labelled as MedCoder text where it appears. Not official text.
Labels on this page: Official source data · MedCoder structured relationship · MedCoder explanation. How to read the labels · All data sources and release dates
Change history
- FY2016 — October 1, 2015In the code set at ICD-10-CM adoptionExposure to other rapid changes in air pressure during descent, subsequent encounter
No changes since FY2016 — additions, deletions, description changes and billable-status changes are tracked through FY2027 (effective October 1, 2026), and none are recorded for this code. Note changes are tracked from FY2027 only.
Nearest Codes in This Family
Official ICD-10-CM classifications closest to W94.39XD in its code family, with their registry titles.
- W94.31 — Exposure to sudden change in air pressure in aircraft during descent
- W94.31XA — Exposure to sudden change in air pressure in aircraft during descent, initial encounter
- W94.31XD — Exposure to sudden change in air pressure in aircraft during descent, subsequent encounter
- W94.31XS — Exposure to sudden change in air pressure in aircraft during descent, sequela
- W94.32 — Exposure to high air pressure from rapid descent in water
- W94.32XA — Exposure to high air pressure from rapid descent in water, initial encounter
- W94.32XD — Exposure to high air pressure from rapid descent in water, subsequent encounter
- W94.32XS — Exposure to high air pressure from rapid descent in water, sequela
- W94.39 — Exposure to other rapid changes in air pressure during descent
- W94.39XA — Exposure to other rapid changes in air pressure during descent, initial encounter