ICD-10 Code I66.3 – Occlusion and stenosis of cerebellar arteries (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code I66.3 – Occlusion and stenosis of cerebellar arteries
What it is
This code describes narrowing or blockage of one or more cerebellar arteries. It is used when blood flow to the cerebellum is reduced due to vascular occlusion or stenosis.
Clinical signs
Clinical features vary; refer to documentation. Common findings may include dizziness, ataxia, vertigo, nausea, or other posterior circulation neurologic deficits consistent with cerebellar ischemia.
When to use this code
Use I66.3 when the provider documents occlusion or stenosis of a cerebellar artery, whether acute, chronic, or related to cerebrovascular disease. This code supports cases where imaging or specialist assessment identifies the affected cerebellar vessel. Check documentation if the record only states stroke, infarction, or nonspecific posterior circulation disease.
Do not use for
Do not use this code for carotid, vertebral, basilar, or other non-cerebellar artery disease. If the diagnosis is cerebral infarction without documented arterial occlusion or stenosis, select the more specific stroke code instead.
Coding tip
Verify the exact artery named in the record; cerebellar artery documentation is required for I66.3.