ICD-10 Code B97.8 – Other viral agents as the cause of diseases classified elsewhere (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code B97.8 – Other viral agents as the cause of diseases classified elsewhere
What it is
This code identifies a viral infection or exposure that is documented as the cause of another condition classified elsewhere. Use it when the virus is named, but the main diagnosis is coded elsewhere.
Clinical signs
Clinical features vary; refer to documentation. You may see signs of a viral illness, but the key point is that the record links a specific viral agent to a separate condition.
When to use this code
Use B97.8 when the provider states that an unspecified or other viral agent caused another coded disease, and the associated condition has its own primary diagnosis code. It is commonly assigned as an additional code to show causation. Confirm that the chart clearly supports the viral etiology.
Do not use for
Do not use this code for a primary viral disease that is coded in the infection chapter. Also avoid it when the documentation does not connect the virus to another condition; check documentation.
Coding tip
Code the underlying condition first, then add B97.8 only when the record explicitly states a viral cause.