A81 Atypical virus infections of central nervous system

⚠ Non-Billable ICD-10-CM 2026
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The ICD-10-CM code for Atypical virus infections of central nervous system is A81 (FY2026). It is a non-billable category code — select a more specific code below for claims.

Classification

Section
A80-A89: Viral and prion infections of the central nervous system (A80-A89)
Category A81
13 codes (10 billable)
FY2026 Status
Stable since FY2024
Includes
  • diseases of the central nervous system caused by prions
Use Additional Code
  • code, if applicable, to identify:
  • dementia with anxiety (F02.84, F02.A4, F02.B4, F02.C4)
  • dementia with behavioral disturbance (F02.81-, F02.A1-, F02.B1-, F02.C1-)
  • dementia with mood disturbance (F02.83, F02.A3, F02.B3, F02.C3)
  • dementia with psychotic disturbance (F02.82, F02.A2, F02.B2, F02.C2)
  • dementia without behavioral disturbance (F02.80, F02.A0, F02.B0, F02.C0)
  • mild neurocognitive disorder due to known physiological condition (F06.7-)

Official Coding Guidelines

HIV Infections (TOC entry)

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

— ICD-10-CM Official Guidelines for Coding and Reporting, FY2026, Section I.C.1.a
Infectious agents causing diseases in other chapters (TOC)

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

— ICD-10-CM Official Guidelines for Coding and Reporting, FY2026, Section I.C.1.b

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

References

Cite This Page

Reference A81 with the canonical source and edition:

A81 — Atypical virus infections of central nervous system. ICD-10 Coding Pro (ICD-10-CM FY2026). https://icd10codingpro.com/codes/A81

Canonical URL: https://icd10codingpro.com/codes/A81

Related Codes

More Specific Codes

A81.0 Creutzfeldt-Jakob disease A81.00 Creutzfeldt-Jakob disease, unspecified A81.01 Variant Creutzfeldt-Jakob disease A81.09 Other Creutzfeldt-Jakob disease A81.1 Subacute sclerosing panencephalitis A81.2 Progressive multifocal leukoencephalopathy A81.8 Other atypical virus infections of central nervous system A81.81 Kuru A81.82 Gerstmann-Sträussler-Scheinker syndrome A81.83 Fatal familial insomnia A81.89 Other atypical virus infections of central nervous system A81.9 Atypical virus infection of central nervous system, unspecified

Related Codes in A81

A81.0 Creutzfeldt-Jakob disease A81.00 Creutzfeldt-Jakob disease, unspecified A81.01 Variant Creutzfeldt-Jakob disease A81.09 Other Creutzfeldt-Jakob disease A81.1 Subacute sclerosing panencephalitis A81.2 Progressive multifocal leukoencephalopathy A81.8 Other atypical virus infections of central nervous system A81.81 Kuru A81.82 Gerstmann-Sträussler-Scheinker syndrome A81.83 Fatal familial insomnia A81.89 Other atypical virus infections of central nervous system A81.9 Atypical virus infection of central nervous system, unspecified
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Reviewed by Prajwal Shrestha, CPC, CRC
Certified Professional Coder (CPC) and Certified Risk Adjustment Coder (CRC) · AAPC Member ID 01997614 · About · Editorial policy · Content last reviewed: 2025-10-01

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