Multiple External Cause Coding Guidelines

More than one external cause code is required to fully describe the external cause of an illness or injury. The assignment of external cause codes should be sequenced in the following priority: If two or more events cause separate injuries, an external cause code should be assigned for each cause.

The first-listed external cause code will be selected in the following order: External codes for child and adult abuse take priority over all other external cause codes. See Section I.C.19., Child and Adult abuse guidelines. External cause codes for terrorism events take priority over all other external cause codes except child and adult abuse.

External cause codes for cataclysmic events take priority over all other external cause codes except child and adult abuse and terrorism. External cause codes for transport accidents take priority over all other external cause codes except cataclysmic events, child and adult abuse and terrorism. Activity and external cause status codes are assigned following all causal (intent) external cause codes.

The first-listed external cause code should correspond to the cause of the most serious diagnosis due to an assault, accident, or self-harm, following the order of hierarchy listed above.