I60.4 Nontraumatic subarachnoid hemorrhage from basilar artery

ICD-10-CM I60.4: Nontraumatic subarachnoid hemorrhage from basilar artery

ICD-10-CM code I60.4 designates a nontraumatic subarachnoid hemorrhage from the basilar artery, classified as a disease or syndrome. It exists as an active terminology record under the broader parent category of nontraumatic subarachnoid hemorrhages. This specific diagnosis code appears in official billing and coding articles, though its presence does not guarantee payer coverage. 1 4

Plain-language overview

Code I60.4 identifies a specific medical diagnosis representing a disease or syndrome rather than a routine service or external cause, providing a standardized way to track this particular cerebrovascular event. 1

What this code represents

The official display label for I60.4 is nontraumatic subarachnoid hemorrhage from basilar artery, and this terminology record is currently active within the ICD-10-CM version 2026 system. 1

This specific diagnosis code is a narrower concept nested under the parent category I60, which encompasses all nontraumatic subarachnoid hemorrhages in the ICD-10-CM coding hierarchy. 1

Coding details

Within the ICD-10-CM code tree, I60.4 sits alongside other distinct intracranial artery hemorrhage codes, including I60.2 for the anterior communicating artery and I60.6 for other intracranial arteries. 6

A research mapping resource associates the clinical description of nontraumatic subarachnoid hemorrhage from basilar artery directly with the I60.4 code, while a Medicare billing article lists adjacent codes for vertebral arteries. 3 4

Documentation considerations

The terminology record for I60.4 specifies the basilar artery as the anatomical origin and classifies the event as nontraumatic, distinguishing it from the unspecified I60.9 code listed in surveillance mapping tools. 1 5

Coverage and utilization context

The I60.4 diagnosis code appears in a Medicare billing and coding article concerning non-invasive cerebrovascular studies, placing it within an administrative context for service claims. 4

What the sources add

While a terminology record defines the code's semantic type as a disease or syndrome, a separate clinical reference document maps broader intracranial hemorrhage codes for surveillance, including the unspecified I60.9 variant. 1 5

A clinical literature index outlines extensive research on subarachnoid hemorrhages, including grading scales, delayed cerebral ischemia, and treatments for basilar artery bifurcation aneurysms, adding clinical context to the diagnosis. 2

Sources

1. ICD-10-CM I60.4 terminology record — National Cancer Institute Enterprise Vocabulary Services; accessed 2026-07-27.
2. Subarachnoid haemorrhage caused by a ruptured aneurysm — ncbi.nlm.nih.gov; accessed 2026-07-27.
3. Phecode 430 · ExPRSweb — csg.sph.umich.edu; accessed 2026-07-27.
4. Article - Billing and Coding: Non-Invasive Cerebrovascular Studies (A57592) — cms.gov; accessed 2026-07-27.
5. Disclaimer — sentinelinitiative.org; accessed 2026-07-27.
6. ICD-10-CM 2024 | I60.9 - Nontraumatic subarachnoid hemorrhage, unspecified — unboundmedicine.com; accessed 2026-07-27.