Pneumonia in other infectious diseases classified elsewhere

This code signifies pneumonia occurring as a complication or manifestation of another underlying infectious disease, where that primary infection is classified elsewhere. It describes a secondary pneumonia, not a primary pneumonia of unknown etiology or a pneumonia due to a specific organism not linked to another infectious process.

Use this code when documentation clearly indicates pneumonia arising in the context of a separately coded infectious disease, such as measles pneumonia, pertussis pneumonia, or influenza with pneumonia. The primary infectious disease should be coded first, followed by this code to specify the associated pneumonia.

• Always sequence the underlying infectious disease first, followed by this code.
• Ensure the documentation explicitly links the pneumonia to another infectious disease. Do not use for primary bacterial or viral pneumonias not associated with another systemic infection.
• Distinguish from codes for pneumonia due to specific organisms (e.g., bacterial pneumonia) when the underlying infectious disease is not separately classified.