A81 ICD-10-CM Code: Atypical virus infections of central nervous system
A clear reference for the official code description, hierarchy, and related coding information from the FY 2027 U.S. release.
Code definition
Official description
A81Atypical virus infections of central nervous system
ICD-10-CM diagnosis code · United States clinical modification
Classification
Where A81 sits
- 1
Chapter 1
Certain infectious and parasitic diseases (A00-B99)
- 2
Section
Viral and prion infections of the central nervous system (A80-A89)
- 3
Category A81
Atypical virus infections of central nervous system
- 4
Code A81
Atypical virus infections of central nervous system
More specific choices
Codes under A81
A81 is a non-billable category. Choose the child code that best matches the documented diagnosis.
Documentation details
Notes for this code
Inclusion terms
No inclusion terms are listed for A81.
Code first
No “code first” instruction is listed for A81.
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-)
Excludes1
Conditions that should not be reported together with this code.
No Excludes1 note is listed for A81.
Excludes2
Conditions not included here that may be reported separately when present.
No Excludes2 note is listed for A81.
Transparency
Source and release
This reference is generated from Vero’s ICD-10-CM description, hierarchy, and code-note dataset. The visible content and structured data share that source.
Review the CDC/NCHS ICD-10-CM sourceCode-specific guidance
Frequently asked questions
What does ICD-10-CM code A81 mean?
A81 is the FY 2027 U.S. ICD-10-CM code for “Atypical virus infections of central nervous system.”
Is A81 a billable or specific ICD-10-CM code?
No. A81 has more specific child codes in the FY 2027 reference data. Select the code that matches the documentation and confirm the active code set and payer requirements.
Where is A81 located in ICD-10-CM?
A81 is listed in Chapter 1, Certain infectious and parasitic diseases (A00-B99), within Viral and prion infections of the central nervous system (A80-A89) (A80–A89), under category A81, Atypical virus infections of central nervous system.
What coding notes are listed for A81?
No inclusion terms are listed for A81 in this reference record. No code-first instruction is listed. Additional-code instructions: 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-). No Excludes1 note is listed. No Excludes2 note is listed.
Ready to transform your clinical documentation?
Join Vero and see how effortless documentation can be.
No credit card required
Cancel anytime