ICD-10 Code B97.3 – Retrovirus as the cause of diseases classified elsewhere (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code B97.3 – Retrovirus as the cause of diseases classified elsewhere
What it is
B97.3 is an external cause code used when a retrovirus is documented as the infectious agent causing another condition classified elsewhere. You use it to identify the organism, not the primary disease.
Clinical signs
Clinical features depend on the linked condition, not the code itself. Documentation should identify a retroviral infection or retrovirus-related cause; if the record is unclear, check documentation.
When to use this code
Use B97.3 when the provider states that a retrovirus is the cause of a separately coded disease, and the record supports that relationship. Pair it with the principal diagnosis for the manifestation or associated condition. If the note only names a viral illness without specifying retrovirus, do not assume this code.
Do not use for
Do not use B97.3 for the primary disease itself or for infections caused by other viruses. If the organism is not documented as a retrovirus, check documentation before coding.
Coding tip
Code the underlying condition first, then add B97.3 only when the chart clearly links the disease to a retrovirus.