External cause status (Y99)

ICD-10 code Y99 represents the category for external cause status, which records the activity status of a person at the time of an injury or external cause event. This classification helps specify whether the affected individual was engaged in work, military service, volunteer work, or other activities when the incident occurred.

These codes are used to detail the context of injuries or external causes, providing clarity for medical coders in billing and documentation. For example, Y99.0 refers to accidents occurring during civilian work-related activities, encompassing situations like drowning during underwater construction or overwork-related deaths. Similarly, Y99.1 captures incidents tied to military activities, including accidents during training or post-traumatic stress disorder following combat. Y99.2 denotes volunteer activities, while Y99.8 covers other external cause statuses such as accidental drownings during recreational activities like fishing or hunting. When the specific activity status is unknown, Y99.9 is used as an unspecified code. Understanding these distinctions is essential for correctly applying the ICD-10 code for external cause status in medical records and claims.