ICD-10 Code B97.89 – Other viral agents as the cause of diseases classified elsewhere (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code B97.89 – Other viral agents as the cause of diseases classified elsewhere
What it is
B97.89 identifies a viral agent documented as causing another condition classified elsewhere. Use it when the record names a virus or viral cause, but the main diagnosis is coded in another category.
Clinical signs
Clinical features vary; refer to documentation. You may see a confirmed viral association with another disease process, but the code itself does not describe symptoms or severity.
When to use this code
Use B97.89 when the provider links a viral agent to a separate primary diagnosis, such as a viral cause of an illness coded elsewhere. It is appropriate when the chart clearly documents the viral etiology, but no more specific code applies. Pair it with the condition being treated or evaluated.
Do not use for
Do not use this code as the principal diagnosis when the condition itself has a more specific code. Do not use it if the viral cause is not documented; check documentation.
Coding tip
Code the underlying condition first, then add B97.89 only when the record supports a documented viral cause.