ICD-10 Code B97.31 – Lentivirus as the cause of diseases classified elsewhere (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code B97.31 – Lentivirus as the cause of diseases classified elsewhere
What it is
B97.31 identifies lentivirus as the infectious agent causing a condition classified in another chapter. You use it when the underlying disease is documented as due to a lentivirus, such as HIV-related illness.
Clinical signs
Clinical features vary; refer to documentation. In practice, you may see evidence of lentiviral infection with related opportunistic disease, immune dysfunction, or other manifestations linked to the documented condition.
When to use this code
Use B97.31 when the provider states that a disease is caused by lentivirus and the main diagnosis is coded elsewhere. It supports sequencing with the condition being treated, not the organism alone. Check the chart for the specific associated disorder and whether the infection is confirmed or documented as causal.
Do not use for
Do not use this code for a nonspecific viral infection or when the record does not link the illness to lentivirus. If the diagnosis is only suspected or documentation is unclear, check documentation.
Coding tip
Code B97.31 only when the chart clearly ties the disease to lentivirus and pair it with the manifestation code.