W20 – Struck by thrown, projected or falling object

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

Non-billable header

ICD-10-CM code W20

Code: W20 (claims format: W20)
Description: Struck by thrown, projected or falling object
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 W20

W20 is a header code and cannot be used on claims. Choose the most specific code:

W20.0 – Struck by falling object in cave-inHeader (more codes below)
W20.1 – Struck by object due to collapse of buildingHeader (more codes below)
W20.8 – Other cause of strike by thrown, projected or falling objectHeader (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 W20

Excludes1 (not coded here):

falling object in machinery accident (W24, W28-W31)
falling object in transport accident (V01-V99)
object set in motion by explosion (W35-W40)
object set in motion by firearm (W32-W34)
struck by thrown sports equipment (W21.-)

Code first:

any associated:
cataclysm (X34-X39)
lightning strike (T75.00)

7th character note:

The appropriate 7th character is to be added to each code from category W20

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 W20?

W20 is the ICD-10-CM code for struck by thrown, projected or falling object, in the block W20-W49 (Exposure to inanimate mechanical forces).

Is W20 a billable code?

No. W20 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.