ICD-10 Code I63.31 – Cerebral infarction due to thrombosis of middle cerebral artery (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code I63.31 – Cerebral infarction due to thrombosis of middle cerebral artery
What it is
This code identifies an ischemic stroke caused by a blood clot blocking the middle cerebral artery. Use it when documentation states cerebral infarction due to thrombosis of the MCA.
Clinical signs
Typical findings include sudden focal neurologic deficits such as weakness, numbness, speech difficulty, or facial droop. Clinical features vary; refer to documentation and imaging evidence of infarction in the MCA territory.
When to use this code
Use this code when the provider documents a cerebral infarction specifically attributed to thrombosis of the middle cerebral artery. It may appear in stroke admissions, emergency records, or discharge summaries with confirmed MCA territory infarction.
If the record only says ischemic stroke, cerebral infarction, or cerebral thrombosis without naming the middle cerebral artery, check documentation before coding. Laterality or additional vessel detail may require a more specific code.
Do not use for
Do not use this code for hemorrhagic stroke, transient ischemic attack, or infarction from embolism or unspecified occlusion. Check documentation if the vessel, cause, or stroke type is not clearly stated.
Coding tip
Match the code to the exact documented vessel and mechanism; if MCA thrombosis is not explicit, verify the provider’s wording before assigning I63.31.