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A81.9

Billable

Atypical virus infection of central nervous system, unsp

Atypical virus infection of central nervous system, unspecified

Status

Billable / Specific

Block

A80-A89

Parent Code

A81

ICD-11 Mapping

1 equivalent

Coding Notes

Inclusion Terms

Alternative clinical terms for this condition

  • Prion diseases of the central nervous system NOS

Includes

Conditions included under this code

  • diseases generally recognized as communicable or transmissible
  • diseases of the central nervous system caused by prions

Excludes 1

Codes that cannot be used together with this code (mutual exclusion)

Excludes 2

Conditions not included here, but the patient may have both

Use Additional Code

Additional codes that should follow this code

Related Codes(4)
A81.0

Creutzfeldt-Jakob disease

A81.1

Subacute sclerosing panencephalitis

BillableA81.2

Progressive multifocal leukoencephalopathy

BillableA81.8

Other atypical virus infections of central nervous system

ICD-11 Equivalents(1)

ICD-11 Equivalents

View full mapping

Corresponding ICD-11 codes from the WHO crosswalk mapping

1C8ZViral infections of the central nervous system, unspecifiedequivalentPrimary
Also Known As / Clinical Terms(116)

SNOMED CT

UMLS

Clinical Terms

  • Transmissible dementias
  • Transmissible Dementia
  • Prion-Induced Disorder
  • Prion disease
  • Dementia, Transmissible
  • Transmissible spongiform encephalopathies
  • Tics due to prion disease
  • Prion-induced disorders
  • Spongiform Encephalopathy, Transmissible
  • disease prion
  • Slow viral central nervous system infection
  • Prion Diseases
  • TRANSM DEMENTIAS
  • PRION IND DIS
  • Prion Protein Diseases
  • Chorea due to prion disease
  • Secondary tic disorder
  • Disorder, Prion-Induced
  • PRION DIS
  • Encephalopathies, Transmissible Spongiform
  • ENCEPH SPONGIFORM TRANSM
  • Spongiform Encephalopathies, Transmissible
  • TRANSM SPONGIFORM ENCEPH
  • TSEs
  • Acquired prion disease
  • prion induced disorder
  • Autonomic disorder due to prion disease
  • diseases prions
  • Disorders, Prion-Induced
  • Tic disorder due to prion disease
  • encephalopathies spongiform
  • Encephalopathies, Spongiform, Transmissible
  • Prion diseases of the central nervous system NOS
  • spongiform encephalopathy
  • disease prions
  • SPONGIFORM ENCEPH TRANSM
  • DEMENTIAS TRANSM
  • Prion-Associated Disorders
  • Disorder of autonomic nervous system due to prion disease
  • Familial Alzheimer-like prion disease
  • Parkinsonism due to prion disease
  • PRION PROTEIN DIS
  • Dementia due to prion disease
  • Transmissible spongiform encephalopathy
  • Prion Protein Disease
  • Encephalopathy, Transmissible Spongiform
  • Dementias, Transmissible
  • diseases prion
  • Prion disease (disorder)
  • Disorder of autonomic nervous system due to infectious disease
Frequently Asked Questions
What is the ICD-10 code for atypical virus infection of central nervous system, unsp?

The ICD-10-CM code for atypical virus infection of central nervous system, unsp is A81.9. The full clinical description is "Atypical virus infection of central nervous system, unspecified". A81.9 is a billable/specific code that can be used on insurance claims and medical billing.

What does ICD-10 code A81.9 mean?

ICD-10-CM code A81.9 represents “Atypical virus infection of central nervous system, unspecified”. It is classified under Chapter 1: Certain Infectious and Parasitic Diseases and is a billable/specific code that can be used on a claim.

Is A81.9 a billable code?

Yes, A81.9 is a billable/specific ICD-10-CM code and can be used to indicate a diagnosis on a medical claim.

What chapter is A81.9 in?

A81.9 is in Chapter 1: Certain Infectious and Parasitic Diseases (codes A00-B99).

What codes cannot be used with A81.9?

A81.9 has Excludes1 notes indicating codes that cannot be used together with it, including: certain localized infections - see body system-related chapters; postpolio syndrome (G14); sequelae of poliomyelitis (B91); and 1 more.

Are additional codes required with A81.9?

Yes, when using A81.9, also report: resistance to antimicrobial drugs (Z16.-); 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-).

What SNOMED CT codes does A81.9 map to?

A81.9 maps to 11 SNOMED CT concepts: 721255002, 1259081008, 1259640001, 762350007, 724811002, and 6 more. SNOMED CT is a clinical terminology used in electronic health records.

What are the UMLS CUIs for A81.9?

A81.9 is linked to 2 UMLS Concept Unique Identifiers: C0851226, C0162534. The UMLS (Unified Medical Language System) integrates multiple biomedical vocabularies maintained by the U.S. National Library of Medicine.

How does A81.9 relate to ICF functioning codes?

ICF (International Classification of Functioning, Disability and Health) codes describe how conditions like atypical virus infection of central nervous system, unsp affect a person's functioning — body functions, activities, participation, and environmental factors. AutoICD provides ICF Core Sets for 12+ conditions and can map clinical text to ICF categories automatically. Browse the ICF directory to explore functioning codes.

What is the ICD-11 equivalent of A81.9?

A81.9 maps to the ICD-11 code: 1C8Z (Viral infections of the central nervous system, unspecified).

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Includes SNOMED Clinical Terms® (SNOMED CT®) used by permission of SNOMED International. Includes content from the UMLS Metathesaurus, courtesy of the U.S. National Library of Medicine.