ICD-10 Code I63.03 – Cerebral infarction due to thrombosis of carotid artery (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code I63.03 – Cerebral infarction due to thrombosis of carotid artery
What it is
I63.03 identifies an ischemic stroke caused by a blood clot blocking the carotid artery and reducing blood flow to the brain. Use it when documentation clearly states carotid artery thrombosis as the cause of cerebral infarction.
Clinical signs
Clinical features vary; refer to documentation. Typical stroke findings may include sudden weakness, speech difficulty, facial droop, or vision loss, with imaging or provider assessment supporting cerebral infarction.
When to use this code
Use this code when the record documents cerebral infarction due to thrombosis of the carotid artery, including carotid occlusion or clot-related ischemic stroke. You should assign it only when the provider links the infarct to the carotid thrombosis. If the cause is not stated, check documentation.
Do not use for
Do not use it for hemorrhagic stroke, transient ischemic attack, or cerebral infarction from another artery. Also avoid it when the chart does not specify carotid thrombosis as the cause.
Coding tip
Confirm the causal artery and stroke type in the provider note before assigning I63.03.