ICD-10 Code I66.13 – Occlusion and stenosis of bilateral anterior cerebral arteries (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code I66.13 – Occlusion and stenosis of bilateral anterior cerebral arteries
What it is
This code identifies narrowing or blockage affecting both anterior cerebral arteries. Use it when the record documents bilateral anterior cerebral artery occlusion or stenosis, usually as a cerebrovascular diagnosis.
Clinical signs
Clinical features vary; refer to documentation. Findings may include signs of cerebral ischemia, such as weakness, speech changes, confusion, or other focal neurologic deficits linked to the affected arterial territory.
When to use this code
Use I66.13 when the provider clearly documents bilateral anterior cerebral artery stenosis or occlusion, whether acute or chronic, and the condition is being coded as a diagnosis. It may appear on imaging reports, neurology notes, or discharge summaries. If the laterality or vessel is unclear, check documentation.
Do not use for
Do not use this code for nonspecific cerebrovascular disease, generalized atherosclerosis, or stroke without documented bilateral anterior cerebral artery involvement. Check documentation if the record only mentions carotid disease or an unspecified cerebral artery.
Coding tip
Confirm both laterality and the exact artery documented before assigning I66.13.