ICD-10 Code A80.9 – Acute poliomyelitis, unspecified (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code A80.9 – Acute poliomyelitis, unspecified
What it is
A80.9 identifies acute poliomyelitis when the specific type is not documented. It refers to a poliovirus infection affecting the nervous system, with the exact clinical form left unspecified.
Clinical signs
Clinical features vary; refer to documentation. Classic findings may include fever, headache, neck stiffness, and asymmetric flaccid weakness or paralysis, but the record must support poliomyelitis.
When to use this code
Use A80.9 when the provider documents acute poliomyelitis but does not specify the type or site. It is appropriate when the diagnosis is confirmed clinically or by testing, yet the chart lacks further detail. You should not infer a more specific code without documentation.
Do not use for
Do not use this code for historical poliomyelitis, post-polio syndrome, or nonspecific viral meningitis/encephalitis. If the documentation identifies a different poliovirus manifestation, check documentation for a more specific code.
Coding tip
Verify that “acute poliomyelitis” is explicitly documented before assigning A80.9.