Coding Viral Meningitis, Viral Encephalitis, Viral Meningoencephalitis and Aseptic Meningitis

While the clinical distinction can sometimes be subtle in young patients, the encoder distinctly differentiates between viral meningitis, viral meningoencephalitis, viral encephalitis and aseptic meningitis. The alphabetic index in the encoder is the best way to reach the appropriate code for these conditions. There are numerous codes/modifiers to comb through. ICD 9 CM Coding Clinic January-February 1987 pages 6 to 7 tells us to use the modifier for the specific organism, if possible. It also provides direction regarding viral meningitis and aseptic meningitis codes. )The relevant ICD-10 codes in are brackets below:)

“Meningitis has a detailed listing of sub term modifiers that are to be referenced for specificity…purulent, granulomatous, and aseptic meningitis are classified to specific organisms in the infectious codes…Aseptic meningitis is presumed to be caused principally by viruses, such as those classified in the 047 category [ICD-10 A87.9]. When no virus or other organism can be identified as the cause of aseptic meningitis, category 322 is assigned [ICD-10 G03.0].”

Pearls/Using the Alphabetic Index in the Encoder

•For all of these conditions, if you know the organism, scroll to that modifier

•Pay attention to includes/excludes notes as these provide further specificity

•A query may be needed for specificity, especially for aseptic vs viral as these terms are often used interchangeably in the clinical world, but are coded differently

For viral meningitis when the organism is not known:

Encoder: meningitis --> viral --> A87.9 (Viral meningitis, unspecified) --> DRG 076 Viral meningitis

For aseptic meningitis, not documented/not presumed to be viral:

Encoder: meningitis --> aseptic --> G03.0 (Nonpyogenic meningitis) --> DRG 099 Non-bacterial infection of nervous system except viral meningitis

For viral encephalitis when the organism is not known:

Encoder: encephalitis à acute – see also Encephalitis, viral A86 --> A86 (Unspecified viral encephalitis) --> DRG 099 Non-bacterial infection of nervous system except viral meningitis

For viral meningoencephalitis when the organism is not known:

Encoder: meningoencephalitis --> see also Encephalitis --> acute --> see also encephalitis, viral A86 --> A86 (Unspecified viral encephalitis) --> DRG 099 Non-bacterial infection of nervous system except viral meningitis