B10.01 Human herpesvirus 6 encephalitis

The ICD-10-CM code for Human herpesvirus 6 encephalitis is B10.01 (FY2026). It is a billable, claim-ready diagnosis code.

Classification

Chapter

1: Certain infectious and parasitic diseases (A00-B99)

Section

B10: Other human herpesviruses (B10)

Category B10

8 codes (5 billable)

FY2026 Status

Stable since FY2024

Also Known As

ICD-10-CM Alphabetic Index entries that lead to B10.01:

• Meningoencephalitis › herpesviral, herpetic › due to herpesvirus 6
• Herpes, herpesvirus, herpetic › encephalitis › due to herpesvirus 6
• Encephalitis (chronic) (hemorrhagic) (idiopathic) (nonepidemic) (spurious) (subacute) › herpesviral › due to herpesvirus 6
• Encephalitis (chronic) (hemorrhagic) (idiopathic) (nonepidemic) (spurious) (subacute) › in (due to) › herpes (simplex) virus › due to herpesvirus 6
• Herpes, herpesvirus, herpetic › human › 6 › encephalitis
• Meningoencephalitis › in (due to) › herpes › due to herpesvirus 6

U.S. Hospital Utilization

• An estimated 435 U.S. inpatient stays in 2023 included B10.01 among the documented diagnoses.
• 180 stays listed it as the principal diagnosis.

Source: National Inpatient Sample (NIS), Healthcare Cost and Utilization Project (HCUP), Agency for Healthcare Research and Quality, 2016–2023. National survey-weighted estimates.

Official Coding Guidelines

HIV Infections (TOC entry)

a. Human Immunodeficiency Virus (HIV) Infections .............................................................. 19

Infectious agents causing diseases in other chapters (TOC)

b. Infectious agents as the cause of diseases classified to other chapters ................................. 22

Source: CMS — ICD-10-CM Official Guidelines for Coding and Reporting, FY2026

References

• CMS — ICD-10-CM Official Code Set and Guidelines, FY2026
• CDC/NCHS — ICD-10-CM Files and Browser Tool
• AHRQ — HCUP National Inpatient Sample, Frequencies by Diagnosis Code (2016–2023)