ICD-10 Code B10.81 – Human herpesvirus 6 infection (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code B10.81 – Human herpesvirus 6 infection
What it is
B10.81 identifies a documented infection caused by human herpesvirus 6. Use it when the provider specifically records HHV-6 infection rather than a nonspecific viral illness.
Clinical signs
Clinical features vary; refer to documentation. HHV-6 infection may be associated with fever, rash, or other viral symptoms, but the diagnosis should be supported by the provider’s assessment.
When to use this code
Use B10.81 when the medical record clearly states human herpesvirus 6 infection, including confirmed or clinically diagnosed cases. It may appear as the primary reason for care or as a documented concurrent infection. If the note only says “viral infection,” check documentation.
Do not use for
Do not use this code for nonspecific febrile illness, rash, or viral syndrome without documented HHV-6 infection. Do not assign it when another herpesvirus is identified instead.
Coding tip
Code only when HHV-6 is explicitly documented; otherwise, query the provider or use the more specific documented diagnosis.