ICD-10 Code J09.X1 – Influenza due to identified novel influenza A virus with pneumonia (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code J09.X1 – Influenza due to identified novel influenza A virus with pneumonia
What it is
Use this code for influenza caused by a documented novel influenza A virus when pneumonia is also present. It identifies a specific viral flu infection with lower respiratory involvement.
Clinical signs
Typical findings include acute influenza symptoms such as fever, cough, sore throat, and body aches, along with clinical or imaging evidence of pneumonia. Clinical features vary; refer to documentation.
When to use this code
Assign J09.X1 when the provider documents novel influenza A and specifies pneumonia as a complication or associated diagnosis. Use it for confirmed cases, not for suspected influenza or pneumonia without the stated viral cause. If documentation is unclear, check documentation before coding.
Do not use for
Do not use this code for seasonal influenza, influenza without pneumonia, or pneumonia from another organism. If the record does not identify a novel influenza A virus, choose a different code.
Coding tip
Verify that both the influenza type and pneumonia are explicitly documented before assigning J09.X1.