ICD-10 Code I66.11 – Occlusion and stenosis of right anterior cerebral artery (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code I66.11 – Occlusion and stenosis of right anterior cerebral artery
What it is
This code identifies narrowing or blockage of the right anterior cerebral artery, one of the brain’s major blood vessels. It is used when documentation specifies the right side and the vessel is intracranial.
Clinical signs
Clinical features vary; refer to documentation. Findings may include symptoms of cerebral ischemia such as weakness, sensory changes, speech difficulty, or altered mental status, depending on the affected territory.
When to use this code
Use I66.11 when the provider documents occlusion or stenosis of the right anterior cerebral artery, with or without acute stroke symptoms. Apply it for imaging-confirmed vascular narrowing or blockage when the anatomic site is clearly stated.
Do not guess laterality or vessel type from nonspecific cerebrovascular notes. If the record only says “cerebral artery stenosis” or “stroke,” check documentation for the exact artery and side before coding.
Do not use for
Do not use this code for extracranial carotid disease, unspecified cerebral artery disease, or historical stroke without current artery occlusion or stenosis. Check documentation.
Coding tip
Confirm both the artery and laterality in the report; I66.11 is only for the right anterior cerebral artery.