A84.1 Central European tick-borne encephalitis

The ICD-10-CM code for Central European tick-borne encephalitis is A84.1 (FY2026). It is a billable, claim-ready diagnosis code.

Classification

Chapter

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

Section

A80-A89: Viral and prion infections of the central nervous system (A80-A89)

Category A84

7 codes (5 billable)

FY2026 Status

Stable since FY2024

Also Known As

ICD-10-CM Alphabetic Index entries that lead to A84.1:

• Meningoencephalitis › diphasic
• Encephalitis (chronic) (hemorrhagic) (idiopathic) (nonepidemic) (spurious) (subacute) › Central European (tick-borne)
• Encephalitis (chronic) (hemorrhagic) (idiopathic) (nonepidemic) (spurious) (subacute) › Czechoslovakian
• Encephalitis (chronic) (hemorrhagic) (idiopathic) (nonepidemic) (spurious) (subacute) › viral, virus › arthropod-borne NEC › tick-borne › diphasic meningoencephalitis
• Encephalitis (chronic) (hemorrhagic) (idiopathic) (nonepidemic) (spurious) (subacute) › viral, virus › arthropod-borne NEC › tick-borne › biundulant
• Encephalitis (chronic) (hemorrhagic) (idiopathic) (nonepidemic) (spurious) (subacute) › viral, virus › arthropod-borne NEC › tick-borne › Czechoslovakian
• Encephalitis (chronic) (hemorrhagic) (idiopathic) (nonepidemic) (spurious) (subacute) › viral, virus › arthropod-borne NEC › tick-borne › central European

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