ICD-10 Code I63.329 – Cerebral infarction due to thrombosis of unspecified anterior cerebral artery (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code I63.329 – Cerebral infarction due to thrombosis of unspecified anterior cerebral artery
What it is
This code identifies an ischemic stroke caused by a blood clot blocking an anterior cerebral artery, but the side is not specified. It indicates brain tissue injury from reduced blood flow in that vessel territory.
Clinical signs
Clinical features vary; refer to documentation. Common findings in anterior cerebral artery stroke include weakness or sensory loss affecting the leg more than the arm, gait difficulty, and possible confusion or behavioral change.
When to use this code
Use this code when the provider documents cerebral infarction from thrombosis of the anterior cerebral artery and does not identify right or left side. It also fits cases where imaging or the note confirms an ACA-territory infarct with thrombotic cause but laterality is absent. If the record names another mechanism, code that documented cause instead.
Do not use for
Do not use it for embolic stroke, hemorrhagic stroke, or cerebral infarction with a specified right or left anterior cerebral artery. Check documentation if the cause is unclear or if the infarct is in a different vascular territory.
Coding tip
Verify both the mechanism and laterality; if either is missing, code only what the provider clearly documents.