Nontraumatic subarachnoid hemorrhage from basilar artery

This code signifies bleeding into the subarachnoid space, the area between the brain and the surrounding membranes, specifically originating from a non-traumatic rupture of the basilar artery. This is a serious type of stroke often caused by an aneurysm.

Apply this code when documentation clearly indicates a spontaneous (nontraumatic) subarachnoid hemorrhage and specifies the basilar artery as the source of the bleeding. Imaging reports (e.g., CT angiography, MRI) confirming the basilar artery as the origin, along with physician notes detailing the hemorrhage, support its use.

• Ensure the documentation explicitly states "nontraumatic" or "spontaneous" to differentiate from traumatic subarachnoid hemorrhage.
• Verify the specific artery involved; do not use this code if the hemorrhage is from an unspecified artery or a different named artery.
• Sequence this code as the principal diagnosis when it is the primary reason for the admission or encounter.