Ill-defined and unknown cause of mortality (R99)

Browse all the diagnosis codes used for ill-defined and unknown cause of mortality (r99). For easy navigation, the diagnosis codes are sorted in alphabetical order and grouped by sections. Each section is clearly marked with its description, and the corresponding three-digit code range. This format makes it simple to browse diagnosis codes in this chapter or section and find what you're looking for. We've also added green checkmark icons to label billable codes, and red warning icons for non-billable ones. This makes it easy to identify which codes can be billed.

Clinical Information

Infant - A child between 1 and 23 months of age.

Infant Death - The death of a live-born INFANT within its first year of life.

Maternal Death - The death of the female parent.

Perinatal Death - The death of a FETUS of GESTATIONAL AGE 28 weeks or more, or the death of a live-born INFANT less than 28 days of age.

Sudden Infant Death - The abrupt and unexplained death of an apparently healthy infant under one year of age, remaining unexplained after a thorough case investigation, including performance of a complete autopsy, examination of the death scene, and review of the clinical history. (Pediatr Pathol 1991 Sep-Oct;11(5):677-84)

Sudden Unexpected Death in Epilepsy - Sudden death in a patient with EPILEPSY associated with SEIZURES and seizure-related symptoms (e.g., APNEA; HYPOXEMIA) without other identifiable accidental causes (e.g., DROWNING; WOUNDS AND INJURIES).

Instructional Notations

Inclusion Terms

These terms are the conditions for which that code is to be used. The terms may be synonyms of the code title, or, in the case of "other specified" codes, the terms are a list of the various conditions assigned to that code. The inclusion terms are not necessarily exhaustive. Additional terms found only in the Alphabetic Index may also be assigned to a code.

  • Death (unexplained) NOS
  • Unspecified cause of mortality