ICD-10 Code for Ischemic Cerebrovascular Incident
The ICD-10 code for an ischemic cerebrovascular incident (stroke) is I63.x, where the fourth and fifth digits specify the subtype of ischemic stroke.
Primary Code and Specificity
The primary ICD-10 code I63 represents "Cerebral infarction" and requires additional digits to specify the type and cause of the ischemic stroke:
- I63.0: Cerebral infarction due to thrombosis of precerebral arteries
- I63.1: Cerebral infarction due to embolism of precerebral arteries
- I63.2: Cerebral infarction due to unspecified occlusion or stenosis of precerebral arteries
- I63.3: Cerebral infarction due to thrombosis of cerebral arteries
- I63.4: Cerebral infarction due to embolism of cerebral arteries
- I63.5: Cerebral infarction due to unspecified occlusion or stenosis of cerebral arteries
- I63.6: Cerebral infarction due to cerebral venous thrombosis, nonpyogenic
- I63.8: Other cerebral infarction
- I63.9: Cerebral infarction, unspecified
Coding Accuracy and Validation
Research has shown that ICD-10 codes for ischemic stroke have high positive predictive value (PPV) for incident cases. A validation study found that the PPV for incident ischemic stroke using I63.x codes was 93% (95% CI: 88%, 99%) 1. This indicates that these codes reliably identify true cases of ischemic stroke.
Additional Relevant Codes
In some circumstances, related codes may be used:
- G46.3: Brain stem stroke syndrome
- G46.4: Cerebellar stroke syndrome
- G45.8: Other transient cerebral ischemic attacks and related syndromes
- G45.9: Transient cerebral ischemic attack, unspecified
Coding Considerations
When coding ischemic stroke, consider the following:
Specificity: Use the most specific code available based on the documented cause (thrombosis, embolism, etc.) and location of the infarct.
Incident vs. Recurrent: For recurrent strokes, the same I63.x codes are used, but accuracy is lower (PPV of 72%) 1. Consider applying a gap of at least 20 days between events to improve accuracy when coding recurrent strokes.
Avoid Common Errors:
- Don't confuse with hemorrhagic stroke codes (I60-I62)
- Don't use history of stroke (Z86.73) for acute events
- Don't use TIA codes (G45.x) for completed strokes
Documentation Requirements: Ensure documentation includes:
- Confirmation of infarction (typically via imaging)
- Etiology if known (embolic, thrombotic, etc.)
- Affected vascular territory
Improving Coding Accuracy
To improve coding accuracy, validation studies suggest combining diagnostic codes with clinical information:
- When diagnostic codes are combined with brain imaging performed within 1 day, the accuracy increases to 90% 2
- Using modifier codes indicating cerebral infarction significantly improves specificity 3
For research and surveillance purposes, ICD-10 has been found to be as accurate as ICD-9 for stroke identification, with approximately 92% correct classification 4.