These categories may be used to provide supplementary information concerning causes of morbidity. They are not to be used for single-condition coding.

  1. Y99 External cause status

    1. Y99.0 Civilian activity done for income or pay

      Inclusion term(s):

      • Civilian activity done for financial or other compensation
    2. Y99.1 Military activity

    3. Y99.2 Volunteer activity

    4. Y99.8 Other external cause status

      Inclusion term(s):

      • Activity NEC
      • Activity of child or other family member assisting in compensated work of other family member
      • Hobby not done for income
      • Leisure activity
      • Off-duty activity of military personnel
      • Recreation or sport not for income or while a student
      • Student activity
    5. Y99.9 Unspecified external cause status

Abbreviations used here:

NEC Not elsewhere classifiable
This abbreviation in the Tabular List represents “other specified”. When a specific code is not available for a condition, the Tabular List includes an NEC entry under a code to identify the code as the “other specified” code.

NOS Not otherwise specified
This abbreviation is the equivalent of unspecified.