MORE VIDEOS
Explore more

Chapter 20: External causes of morbidity (V00–Y99)

This chapter records how an injury or health event happened — falls, transport accidents, accidental poisoning and other external causes. Its codes are used together with the injury codes in Chapter 19 rather than on their own.

Chapter 20 spans codes V00–Y99 in the FY2027 ICD-10-CM tabular list. This guide explains 12 of its most common codes — select a code for its official description, a plain-English explanation and a note on when the code is used.

ICD-10 Chapter 20: External Causes of Morbidity — illustrative image

Codes in this chapter

CodeOfficial descriptionIn plain words
V89.2XXAPerson injured in unspecified motor-vehicle accident, traffic, initial encounterAn external-cause code recording that a person was injured in a motor-vehicle accident (traffic), the vehicle and role not specified; first encounter.
W01.0XXAFall on same level from slipping, tripping and stumbling without subsequent striking against object, initial encounterAn external-cause code recording a fall on the same level from slipping, tripping or stumbling, without striking an object; first encounter.
W10.9XXAFall (on) (from) unspecified stairs and steps, initial encounterAn external-cause code recording a fall on or from stairs or steps (not further specified); first encounter.
W19.XXXAUnspecified fall, initial encounterAn external-cause code recording a fall whose circumstances are not specified; first encounter.
W54.0XXABitten by dog, initial encounterAn external-cause code recording a bite by a dog; first encounter. Used alongside the injury code for the wound itself.
W55.01XABitten by cat, initial encounterAn external-cause code recording a scratch by a cat; first encounter.
W57.XXXABitten or stung by nonvenomous insect and other nonvenomous arthropods, initial encounterAn external-cause code recording a bite or sting by a nonvenomous insect or other nonvenomous arthropod, such as a tick or bedbug; first encounter.
X50.0XXAOverexertion from strenuous movement or load, initial encounterAn external-cause code recording overexertion from strenuous movement or load, such as lifting something heavy; first encounter.
X58.XXXAExposure to other specified factors, initial encounterAn external-cause code recording exposure to other specified factors as the cause of an injury or condition; first encounter.
Y92.9Unspecified place or not applicableAn external-cause code recording that the place where an injury or exposure occurred is unspecified or not applicable.
Y93.9Activity, unspecifiedAn external-cause code recording that the activity being performed when an injury occurred is unspecified.
Y99.9Unspecified external cause statusAn external-cause code recording that the person's status (such as civilian or military) at the time of injury is unspecified.

This guide explains ICD-10-CM codes in plain language for patients, students and other readers. It is educational information only — not coding, billing or medical advice. The code recorded for any real encounter is assigned from the full clinical documentation by the treating team and qualified coders, and only they can decide which code fits a specific case.

Other chapters

← ICD-10 Codes home