ICD-10 Code I60.4 – Nontraumatic subarachnoid hemorrhage from basilar artery (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code I60.4 – Nontraumatic subarachnoid hemorrhage from basilar artery
What it is
This code identifies a spontaneous subarachnoid hemorrhage arising from the basilar artery. It means bleeding has occurred into the space around the brain without trauma, and the source is documented as the basilar artery.
Clinical signs
Common findings include sudden severe headache, nausea, vomiting, neck stiffness, and altered mental status. Clinical features vary; refer to documentation, imaging, and the recorded bleeding source.
When to use this code
Use I60.4 when the provider documents a nontraumatic subarachnoid hemorrhage specifically from the basilar artery. Apply it when imaging, operative notes, or discharge documentation identifies that artery as the source. If the vessel source is not stated, check documentation before coding.
Do not use for
Do not use this code for traumatic subarachnoid hemorrhage or when the hemorrhage source is another artery. If the record only says subarachnoid hemorrhage without a basilar artery source, check documentation.
Coding tip
Code the exact artery named by the provider; unspecified source documentation should not be assumed to be basilar.