I63.339

Billable

Cerebral infarction due to thrombosis of unspecified posterior cerebral artery

HCC Category Mapping

V28HCC 249 — Ischemic or Unspecified Stroke

0.289

V24HCC 100 — Ischemic or Unspecified Stroke

0.262

ESRDHCC 100 — Ischemic or Unspecified Stroke

0.000

What This Code Means

A stroke caused by a blood clot in one of the posterior cerebral arteries in the back of the brain, but the specific side is not documented.

Coding Tips

•Query the provider if laterality (right, left, or bilateral) can be determined from clinical documentation or imaging reports
•This code indicates insufficient specificity; attempt to obtain more detailed information before defaulting to 'unspecified'

Clinical Significance

This code identifies an acute ischemic stroke caused by thrombosis (in-situ clot formation) of the unspecified posterior cerebral artery, requiring precise documentation of the clot mechanism. The posterior cerebral artery supplies the occipital lobe, medial temporal lobe, and thalamus. Infarction in this territory affects vision and memory. Accurate coding of the mechanism, artery, and laterality is critical for risk adjustment and tracking stroke subtypes for quality measures and secondary prevention strategies.

Documentation Requirements

✓Provider documentation of acute cerebral infarction (stroke) as a confirmed diagnosis, not rule-out or suspected
✓Identification of the affected artery as the posterior cerebral artery
✓Documentation of laterality (unspecified) supported by clinical findings and/or imaging
✓Documentation that thrombosis (in-situ clot formation) is the underlying mechanism, typically supported by vascular imaging such as computed tomography angiography or magnetic resonance angiography
✓Neurological examination findings consistent with the identified vascular territory (e.g., contralateral homonymous hemianopia, visual agnosia, memory deficits, and thalamic sensory loss)
✓Brain imaging (computed tomography or magnetic resonance imaging) confirming acute infarction
✓Timing of symptom onset to confirm acute presentation
✓Documentation of stroke severity (National Institutes of Health Stroke Scale score preferred)
✓Treatment administered (thrombolytics, thrombectomy, antiplatelet therapy, anticoagulation)

Commonly Confused Codes

I63.439 — Cerebral infarction due to embolism of unspecified posterior cerebral artery; use for embolic rather than thrombotic mechanism I69.3xx — Sequelae of cerebral infarction; use for residual deficits from a prior stroke during follow-up visits, not during the acute event G45.9 — Transient cerebral ischemic attack, unspecified; use when symptoms resolve completely within 24 hours with no evidence of infarction on imaging

Code Hierarchy

└I63Cerebral infarction └I63.3Cerebral infarction due to thrombosis of cerebral arteries └I63.33Cerebral infarction due to thrombosis of posterior cerebral artery └I63.339Cerebral infarction due to thrombosis of unspecified posterior cerebral artery

└I63.339Cerebral infarction due to thrombosis of unspecified posterior cerebral artery