A86 vs A88
A86 (Unspecified viral encephalitis) compared with A88 (Other viral infections of central nervous system, not elsewhere classified), from the official CMS tabular data. Do not report these codes together: the official tabular list marks them Excludes1.
Can these codes be reported together?
No — do not report together. A88 carries an Excludes1 note covering A86: “viral encephalitis NOS (A86)”
Sole exception: when the two conditions are documented as unrelated to each other (ICD-10-CM Official Guidelines, Section I.A.12.a).
Side by side
| A86Unspecified viral encephalitis | A88Other viral infections of central nervous system, not elsewhere classified | |
|---|---|---|
| Billing status | Billable | Non-billable header |
| Classification | A00-B99 — Certain Infectious and Parasitic Diseases (A00-B99) | A00-B99 — Certain Infectious and Parasitic Diseases (A00-B99) |
| Definition | Unspecified viral encephalitis is a billable ICD-10-CM diagnosis code (A86). | Other viral infections of central nervous system, not elsewhere classified is a non-billable ICD-10-CM category code (A88). |
| Includes | Viral encephalomyelitis NOS Viral meningoencephalitis NOS | — |
Derived from the official CMS ICD-10-CM tabular data (FY2026). Not billing advice; verify sequencing rules for the encounter. All data sources