ICD10BillableValid for clinical use
ICD-10 Code A89: Unspecified viral infection of central nervous system
Reviewed by HealthAssure Clinical TeamUpdated 26 May 2026
What is this code?
ICD-10 codes are diagnosis classification codes used in healthcare records, reporting, coding workflows, and billing support. This code sits within the broader ICD-10 area for Certain infectious and parasitic diseases (A00-B99).
When is it used?
- May be used when a clinician documents unspecified viral infection of central nervous system in a patient's medical record.
- May appear in hospital records, claims, referrals, and clinical documentation.
- This code can be used as a clinically usable diagnosis entry in standardized coding workflows.
What it does not mean
- A code alone does not explain severity, treatment plan, or outcome.
- A medical code should not be treated as a substitute for a doctor's diagnosis or advice.
Code hierarchy
chapter
1Certain infectious and parasitic diseases (A00-B99)
block
A80-A89Viral and prion infections of the central nervous system
currentA80-A89
Where you may see this code
You may see this code in hospital records, discharge summaries, insurance claims, encounter documentation, referrals, or other healthcare billing and coding records.
Related specialists
Infectious Disease SpecialistGeneral Physician
Related codes
A80Acute poliomyelitiscategoryA81Atypical virus infections of central nervous systemcategoryA82RabiescategoryA83Mosquito-borne viral encephalitiscategoryA84Tick-borne viral encephalitiscategoryA85Other viral encephalitis, not elsewhere classifiedcategoryA86Unspecified viral encephalitiscodeA87Viral meningitiscategoryA88Other viral infections of central nervous system, not elsewhere classifiedcategory
Sibling codes
A80Acute poliomyelitisA81Atypical virus infections of central nervous systemA82RabiesA83Mosquito-borne viral encephalitisA84Tick-borne viral encephalitisA85Other viral encephalitis, not elsewhere classifiedA86Unspecified viral encephalitisbillableA87Viral meningitisA88Other viral infections of central nervous system, not elsewhere classified
Coverage-related procedures and services
CPT 70460high
COMPUTED TOMOGRAPHY, HEAD OR BRAIN; WITH CONTRAST MATERIAL(S)
Source: CMS coverage guidance
CPT 70450high
COMPUTED TOMOGRAPHY, HEAD OR BRAIN; WITHOUT CONTRAST MATERIAL
Source: CMS coverage guidance
CPT 70470high
COMPUTED TOMOGRAPHY, HEAD OR BRAIN; WITHOUT CONTRAST MATERIAL, FOLLOWED BY CONTRAST MATERIAL(S) AND FURTHER SECTIONS
Source: CMS coverage guidance
HCPCS G2189high
PATIENTS WITH CLINICAL INDICATIONS FOR IMAGING OF THE HEAD: ABNORMAL NEUROLOGIC EXAM
Source: CMS coverage guidance
HCPCS G2187high
PATIENTS WITH CLINICAL INDICATIONS FOR IMAGING OF THE HEAD: HEAD TRAUMA
Source: CMS coverage guidance
HCPCS G2190high
PATIENTS WITH CLINICAL INDICATIONS FOR IMAGING OF THE HEAD: HEADACHE RADIATING TO THE NECK
Source: CMS coverage guidance
Mapped diagnoses and classifications
Coding guidelines
Compatibility
Legacy and official ICD code match exactly.
Legacy codes
A89
Common synonyms
Unspecified viral infection of central nervous system
Frequently asked questions
About this content
This page is prepared by HealthAssure's clinical team using official coding standards from ICD-10. AI tools assist with drafting explanations, which are then reviewed and verified by healthcare professionals for accuracy. This content is for informational purposes and does not replace professional medical advice. Meet our team.