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v1.0.0
ICD-10 Guide
ICD-10 CodesA81.89

A81.89

Other atypical virus infections of central nervous system

BILLABLE STATUSYes
IMPLEMENTATION DATEOctober 1, 2015
LAST UPDATED09/05/2025

Code Description

ICD-10 A81.89 is a billable code used to indicate a diagnosis of other atypical virus infections of central nervous system.

Key Diagnostic Point:

Atypical virus infections of the central nervous system (CNS) encompass a range of viral pathogens that do not fit into the more common categories of viral encephalitis or meningitis. These infections can be caused by viruses such as the human immunodeficiency virus (HIV), cytomegalovirus (CMV), and others that may lead to neurological complications. Patients may present with a variety of symptoms including altered mental status, seizures, focal neurological deficits, and signs of increased intracranial pressure. Diagnosis often involves neuroimaging, lumbar puncture for cerebrospinal fluid analysis, and serological tests to identify the specific viral agent. Vaccination status can play a crucial role in the prevention of certain viral infections, and understanding a patient's immunization history is essential in the clinical assessment. The management of atypical viral CNS infections may require antiviral therapy, supportive care, and monitoring for complications such as secondary infections or neurological sequelae.

Code Complexity Analysis

Complexity Rating: Medium

Medium Complexity

Complexity Factors

  • Variety of atypical viruses that can cause CNS infections
  • Need for comprehensive patient history including vaccination status
  • Differentiation from more common viral CNS infections
  • Potential for overlapping symptoms with other neurological conditions

Audit Risk Factors

  • Inadequate documentation of the specific viral agent
  • Failure to include vaccination history
  • Misclassification of symptoms as more common viral infections
  • Lack of detailed clinical findings in medical records

Specialty Focus

Medical Specialties

Neurology

Documentation Requirements

Detailed neurological examination findings, imaging results, and laboratory tests.

Common Clinical Scenarios

Patients presenting with seizures, altered mental status, or focal neurological deficits.

Billing Considerations

Consideration of atypical viral infections in immunocompromised patients.

Infectious Disease

Documentation Requirements

Comprehensive history of exposure, vaccination status, and laboratory confirmation of viral infection.

Common Clinical Scenarios

Patients with unexplained neurological symptoms and a history of viral infections.

Billing Considerations

Need for interdisciplinary collaboration for accurate diagnosis and management.

Coding Guidelines

Inclusion Criteria

Use A81.89 When
  • According to ICD
  • 10 coding guidelines, A81
  • 89 should be used when the specific atypical viral infection is not classified elsewhere
  • Coders should ensure that the documentation supports the diagnosis and that other potential causes of CNS symptoms are ruled out

Exclusion Criteria

Do NOT use A81.89 When
No specific exclusions found.

Related CPT Codes

87491CPT Code

Viral detection by nucleic acid (DNA or RNA)

Clinical Scenario

Used when testing for specific atypical viruses in CNS infections.

Documentation Requirements

Document the reason for testing and the specific viruses being tested.

Specialty Considerations

Infectious disease specialists may require additional documentation for testing.

ICD-10 Impact

Diagnostic & Documentation Impact

Enhanced Specificity

ICD-10 Improvements

The transition to ICD-10 has allowed for more specific coding of atypical viral infections, improving the accuracy of data collection and reimbursement processes. A81.89 provides a distinct code for atypical infections that were previously grouped under broader categories in ICD-9.

ICD-9 vs ICD-10

The transition to ICD-10 has allowed for more specific coding of atypical viral infections, improving the accuracy of data collection and reimbursement processes. A81.89 provides a distinct code for atypical infections that were previously grouped under broader categories in ICD-9.

Reimbursement & Billing Impact

reimbursement processes. A81.89 provides a distinct code for atypical infections that were previously grouped under broader categories in ICD-9.

Resources

Clinical References

  • •
    CDC Viral Infections

Coding & Billing References

  • •
    CDC Viral Infections

Frequently Asked Questions

What are the common atypical viruses that can cause CNS infections?

Common atypical viruses include cytomegalovirus (CMV), Epstein-Barr virus (EBV), and human immunodeficiency virus (HIV). Each can lead to unique clinical presentations and complications.