A81

Atypical virus infections of central nervous system

Header / non-billable

This code does not map to a risk-adjusting HCC in the loaded models.

Coding notes

Excludes 1 never coded together · Excludes 2 may co-exist

This code · A81
Includes

diseases of the central nervous system caused by prions

Use additional

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-)

Inherited from A80-A89Viral and prion infections of the central nervous system
Excludes 1

postpolio syndrome (G14) sequelae of poliomyelitis (B91) sequelae of viral encephalitis (B94.1)

Inherited from chapter 1Certain infectious and parasitic diseases
Includes

diseases generally recognized as communicable or transmissible

Excludes 1

certain localized infections - see body system-related chapters

Excludes 2

carrier or suspected carrier of infectious disease (Z22.-) infectious and parasitic diseases complicating pregnancy, childbirth and the puerperium (O98.-) infectious and parasitic diseases specific to the perinatal period (P35-P39) influenza and other acute respiratory infections (J00-J22)

Use additional

code to identify resistance to antimicrobial drugs (Z16.-)

Official Guidelines for A81

FY 2026 ›