ICD-10 Code I63.312 – Cerebral infarction due to thrombosis of left middle cerebral artery (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code I63.312 – Cerebral infarction due to thrombosis of left middle cerebral artery
What it is
This code identifies an ischemic stroke caused by a blood clot blocking the left middle cerebral artery. It reflects brain tissue injury from reduced blood flow in that specific artery.
Clinical signs
Typical findings include sudden neurologic deficits such as right-sided weakness, speech or language impairment, and facial droop. Clinical features vary; refer to documentation for the confirmed vascular territory and stroke type.
When to use this code
Use this code when the record clearly states cerebral infarction due to thrombosis of the left middle cerebral artery. You should also use it when imaging or provider documentation identifies an ischemic infarct in that artery’s territory. Check documentation if the side, vessel, or mechanism is not explicit.
Do not use for
Do not use this code for hemorrhagic stroke, transient ischemic attack, or infarction from another cerebral artery. Do not assign it when the chart only says “stroke” without confirming thrombosis of the left middle cerebral artery.
Coding tip
Verify both the infarction and the left middle cerebral artery involvement in the provider note or imaging report before assigning I63.312.