A85 vs B26.2
A85 (Other viral encephalitis, not elsewhere classified) compared with B26.2 (Mumps encephalitis), 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. A85 carries an Excludes1 note covering B26.2: “encephalitis due to mumps virus (B26.2)”
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
| A85Other viral encephalitis, not elsewhere classified | B26.2Mumps encephalitis | |
|---|---|---|
| Billing status | Non-billable header | Billable |
| Classification | A00-B99 — Certain Infectious and Parasitic Diseases (A00-B99) | A00-B99 — Certain Infectious and Parasitic Diseases (A00-B99) |
| Definition | Other viral encephalitis, not elsewhere classified is a non-billable ICD-10-CM category code (A85). | Mumps encephalitis is a billable ICD-10-CM diagnosis code (B26.2). |
| Includes | specified viral encephalomyelitis NEC specified viral meningoencephalitis NEC | epidemic parotitis infectious parotitis |
Derived from the official CMS ICD-10-CM tabular data (FY2026). Not billing advice; verify sequencing rules for the encounter. All data sources