A85 vs A87.2
A85 and A87.2 can never be reported together. ICD-10-CM declares them mutually exclusive with an Excludes1 note, meaning the two conditions cannot occur in the same patient — so exactly one of them is correct for any given encounter.
The official note, declared on A85
lymphocytic choriomeningitis (A87.2)
A85
Other viral encephalitis, not elsewhere classified
Not billable
- Chapter 1
- Certain infectious and parasitic diseases
- Section
- A80-A89
Use when the record says
- specified viral encephalomyelitis NEC
- specified viral meningoencephalitis NEC
A87.2
Lymphocytic choriomeningitis
Billable
- Chapter 1
- Certain infectious and parasitic diseases
- Section
- A80-A89
Use when the record says
- Lymphocytic meningoencephalitis
Indexed under
- Chorioencephalitis (acute) (lymphocytic) (serous)
- Choriomeningitis (acute) (lymphocytic) (serous)
- Encephalitis › lymphatica (chronic) (hemorrhagic) (idiopathic) (nonepidemic) (spurious) (subacute)
- Lymphocytic › chorioencephalitis
- Lymphocytic › choriomeningitis
Excludes1 is not always absolute: where two conditions covered by the note are genuinely unrelated, CMS guidance permits reporting both. Document the reasoning rather than assuming it. More on Excludes1 vs Excludes2 · FY2027