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Compare/W40 vs X00

W40 vs X00

W40 (Explosion of other materials) compared with X00 (Exposure to uncontrolled fire in building or structure), from the official CMS tabular data. Both may be reported when both conditions are documented (Excludes2).

Can these codes be reported together?

Yes, when both are documented. X00 carries an Excludes2 note covering W40: “explosions (W35-W40)”

Excludes2 marks distinct conditions — both may be reported when both are documented.

Side by side

W40Explosion of other materialsX00Exposure to uncontrolled fire in building or structure
Billing statusNon-billable header

Report instead: W40.0XXA, W40.0XXD, W40.0XXS, W40.1XXA, W40.1XXD

Non-billable header

Report instead: X00.0XXA, X00.0XXD, X00.0XXS, X00.1XXA, X00.1XXD

ClassificationV00-Y99 — External Causes of Morbidity (V00-Y99)V00-Y99 — External Causes of Morbidity (V00-Y99)
DefinitionExplosion of other materials is a non-billable ICD-10-CM category code (W40).Exposure to uncontrolled fire in building or structure is a non-billable ICD-10-CM category code (X00).
7th characterThe appropriate 7th character is to be added to each code from category W40The appropriate 7th character is to be added to each code from category X00
Includes
conflagration in building or structure
Code first
any associated cataclysm

Derived from the official CMS ICD-10-CM tabular data (FY2026). Not billing advice; verify sequencing rules for the encounter. All data sources