ICD-10 Code A81.2 – Progressive multifocal leukoencephalopathy (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code A81.2 – Progressive multifocal leukoencephalopathy
What it is
Progressive multifocal leukoencephalopathy is a rare, usually severe demyelinating disease of the brain caused by JC virus infection. Use this code when documentation identifies PML by name.
Clinical signs
Clinical features vary; refer to documentation. Commonly reported findings include progressive focal neurologic deficits, such as weakness, speech changes, visual disturbance, or cognitive decline.
When to use this code
Use A81.2 when the provider documents progressive multifocal leukoencephalopathy, PML, or JC virus-related demyelinating disease. It may also apply when the note clearly states the diagnosis without needing further confirmation. Check documentation if the record only mentions suspected demyelination.
Do not use for
Do not use this code for nonspecific white matter disease, multiple sclerosis, or other demyelinating disorders unless PML is documented. If the diagnosis is uncertain, check documentation.
Coding tip
Code A81.2 only when the chart explicitly supports PML; avoid assigning it from imaging findings alone.