W40 – Explosion of other materials

ICD-10-CM 2027 diagnosis code · Exposure to inanimate mechanical forces

Non-billable header

ICD-10-CM code W40

Code: W40 (claims format: W40)
Description: Explosion of other materials
Billable: No – use a more specific code below
Valid for: Dates of service October 1, 2026 – September 30, 2027 (FY2027)
Chapter: 20. External causes of morbidity (V00-Y99)
Block: W20-W49 Exposure to inanimate mechanical forces

Billable codes under W40

W40 is a header code and cannot be used on claims. Choose the most specific code:

W40.0 – Explosion of blasting materialHeader (more codes below)
W40.1 – Explosion of explosive gasesHeader (more codes below)
W40.8 – Explosion of other specified explosive materialsHeader (more codes below)
W40.9 – Explosion of unspecified explosive materialsHeader (more codes below)

7th character values

Codes in this category need a 7th character to describe the encounter or episode of care (use placeholder X for empty positions).

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

Notes for W40

Excludes1 (not coded here):

assault by explosive material (X96)
explosion involving legal intervention (Y35.1-)
explosion involving military or war operations (Y36.0-, Y36.2-)
intentional self-harm by explosive material (X75)

7th character note:

The appropriate 7th character is to be added to each code from category W40

Notes inherited from parent codes

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

Block W20-W49

Excludes1 (not coded here):

assault (X92-Y09)
contact or collision with animals or persons (W50-W64)
exposure to inanimate mechanical forces involving military or war operations (Y36.-, Y37.-)
intentional self-harm (X71-X83)

Frequently asked questions

What is ICD-10 code W40?

W40 is the ICD-10-CM code for explosion of other materials, in the block W20-W49 (Exposure to inanimate mechanical forces).

Is W40 a billable code?

No. W40 is a header code with more specific child codes; report one of the billable codes listed above.

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.