ICD-10 Code G45.1 – Carotid artery syndrome (hemispheric) (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code G45.1 – Carotid artery syndrome (hemispheric)
What it is
G45.1 identifies a transient ischemic episode caused by reduced blood flow in the carotid artery territory. It is a short-lived neurologic event affecting one cerebral hemisphere.
Clinical signs
Typical findings include sudden weakness, numbness, or speech disturbance on one side of the body. Clinical features vary; refer to documentation for laterality, duration, and whether symptoms fully resolved.
When to use this code
Use G45.1 when the record documents carotid-territory transient ischemic symptoms, often described as hemispheric TIA or carotid artery syndrome. Code it when the provider links the episode to carotid ischemia rather than to vertebrobasilar symptoms or completed stroke.
Do not use for
Do not use this code for persistent neurologic deficits, confirmed cerebral infarction, or non-carotid TIA syndromes. Check documentation if the chart only says “stroke-like symptoms” without a clear carotid-territory diagnosis.
Coding tip
Confirm the provider documents a transient hemispheric event tied to carotid circulation before assigning G45.1.