ICD-10 Code J09.X9 – Influenza due to identified novel influenza A virus with other manifestations (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code J09.X9 – Influenza due to identified novel influenza A virus with other manifestations
What it is
This code identifies influenza caused by a confirmed novel influenza A virus when the illness includes manifestations not captured by other specific J09 codes. Use it when the record links the infection to a novel influenza A strain.
Clinical signs
Typical influenza findings include abrupt fever, cough, sore throat, myalgia, headache, and fatigue. Clinical features vary; refer to documentation for the specific manifestations that support the diagnosis.
When to use this code
Use J09.X9 when the provider documents influenza from an identified novel influenza A virus and the chart does not specify a more exact J09 subtype or manifestation code. You should code it from confirmed documentation, not from suspected exposure alone. Check documentation if the record is unclear.
Do not use for
Do not use this code for seasonal influenza, influenza-like illness, or unspecified viral respiratory infection. Avoid it when the chart does not identify a novel influenza A virus.
Coding tip
Match the code to the provider’s exact wording and verify whether a more specific J09 code applies before defaulting to J09.X9.