Viral and prion infections of the central nervous system
ICD-10 Codes (51)
A81A81.0A81.00A81.01A81.09A81.1A81.2A81.8A81.81A81.82A81.83A81.89A81.9A82A82.0A82.1A82.9A83A83.0A83.1A83.2A83.3A83.4A83.5A83.6A83.8A83.9A84A84.0A84.1A84.8A84.81A84.89A84.9A85A85.0A85.1A85.2A85.8A86A87A87.0A87.1A87.2A87.8A87.9A88A88.0A88.1A88.8A89Updates & Changes
FY 2026 Updates
New Codes (2)
Revised Codes (2)
Deleted Codes
No codes deleted in this range for FY 2026
Historical Changes
- •FY 2025: Routine maintenance updates with minor terminology clarifications
- •FY 2024: Enhanced specificity requirements for certain code ranges
- •FY 2023: Updated documentation guidelines for improved clarity
Upcoming Changes
- •Proposed updates pending review by Coordination and Maintenance Committee
- •Under consideration: Enhanced digital health integration codes
Implementation Guidance
- •Review all FY 2026 updates for A80-A89 codes before implementation
- •Always verify the most current codes in the ICD-10-CM manual
- •Ensure clinical documentation supports the selected diagnosis codes
- +3 more guidance items...
Range Overview
The ICD-10 code range A80-A89 is designated for viral and prion infections of the central nervous system (CNS). This includes conditions such as acute poliomyelitis, aseptic meningitis, and other viral infections characterized by CNS involvement. It also covers prion diseases, which are rare progressive neurodegenerative disorders that affect both humans and animals. These codes are used to classify and track these diseases for epidemiological purposes, and are essential for accurate medical billing and insurance reimbursement.
Key Usage Points:
- •These codes are used when a patient has a confirmed diagnosis of a viral or prion infection of the CNS.
- •The specific type of infection and its manifestations should be accurately documented to select the correct code.
- •The use of a fifth or sixth character is required for some codes in this range to specify the type of infection and its manifestations.
- •For prion diseases, the code selection depends on the specific type of prion disease diagnosed.
- •In some cases, additional codes may be used to identify any associated conditions or complications.
Coding Guidelines
When to Use:
- ✓When a patient is diagnosed with acute poliomyelitis.
- ✓When a patient has a confirmed case of aseptic meningitis.
- ✓When a patient is diagnosed with a specific prion disease, such as Creutzfeldt-Jakob disease.
- ✓When a patient has a viral infection characterized by CNS involvement.
- ✓When a patient has a viral encephalitis not elsewhere classified.
When NOT to Use:
- ✗When a patient has symptoms suggestive of a CNS infection, but no confirmed diagnosis.
- ✗When a patient has a bacterial, fungal, or parasitic CNS infection.
- ✗When a patient has a non-infectious neurological disorder.
- ✗When a patient has a viral infection without CNS involvement.
- ✗When a patient has a prion disease that affects parts of the body other than the CNS.
Code Exclusions
Always verify exclusions by referring to the official ICD-10 guidelines and the specific code's instructions.
Documentation Requirements
Accurate documentation is crucial for coding within the A80-A89 range. The specific type of infection, its manifestations, and any associated conditions or complications should be clearly documented. The documentation should also include the patient's symptoms, clinical findings, diagnostic tests, and treatment plan.
Clinical Information:
- •Specific type of viral or prion infection.
- •Clinical manifestations of the infection.
- •Any associated conditions or complications.
- •Results of diagnostic tests.
- •Treatment plan.
Supporting Evidence:
- •Laboratory reports confirming the infection.
- •Imaging studies showing CNS involvement.
- •Clinical notes detailing the patient's symptoms and findings on physical examination.
- •Notes on the patient's response to treatment.
Good Documentation Example:
Patient presented with fever, headache, and stiff neck. CSF analysis confirmed aseptic meningitis. Patient responded well to antiviral treatment.
Poor Documentation Example:
Patient diagnosed with CNS infection.
Common Documentation Errors:
- âš Not specifying the type of infection.
- âš Not documenting the clinical manifestations of the infection.
- âš Not including supporting evidence such as laboratory reports.
- âš Not documenting the patient's response to treatment.
Range Statistics
Coding Complexity
Coding within the A80-A89 range is of medium complexity due to the need to accurately identify the specific type of infection and its clinical manifestations. This often requires interpretation of laboratory reports and other supporting evidence. Additionally, coders need to stay up to date with changes to the ICD-10 guidelines, as these can affect code selection.
Key Factors:
- â–¸Identifying the specific type of infection.
- â–¸Determining the clinical manifestations of the infection.
- â–¸Identifying any associated conditions or complications.
- â–¸Interpreting supporting evidence such as laboratory reports.
- â–¸Keeping up to date with changes to the ICD-10 guidelines.
Specialty Focus
The A80-A89 range is primarily used by infectious disease specialists, neurologists, and general practitioners. It is also relevant for public health professionals tracking the epidemiology of these diseases.
Primary Specialties:
Clinical Scenarios:
- • A patient presenting with fever, headache, and stiff neck who is diagnosed with aseptic meningitis.
- • A patient with a history of travel to a region with a polio outbreak who develops acute flaccid paralysis.
- • A patient with rapidly progressive dementia who is diagnosed with Creutzfeldt-Jakob disease.
- • A patient with a viral encephalitis not elsewhere classified.
- • A patient with a viral infection characterized by CNS involvement.
Resources & References
There are several resources available for coding within the A80-A89 range. These include the official ICD-10 guidelines, clinical reference books, and educational materials from professional coding organizations.
Official Guidelines:
- ICD-10-CM Official Guidelines for Coding and Reporting
- World Health Organization's ICD-10 online browser
- National Center for Health Statistics' ICD-10-CM webpage
Clinical References:
- Harrison's Principles of Internal Medicine
- Mandell, Douglas, and Bennett's Principles and Practice of Infectious Diseases
Educational Materials:
- American Health Information Management Association's coding resources
- American Academy of Professional Coders' ICD-10 training materials
Frequently Asked Questions
Can I use a code from the A80-A89 range if the patient has a suspected, but not confirmed, CNS infection?
No, these codes should only be used when the patient has a confirmed diagnosis of a viral or prion CNS infection. If the infection is suspected but not confirmed, use a code from the R00-R99 range for symptoms, signs, and abnormal clinical and laboratory findings, not elsewhere classified.