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ICD-10 Guide
ICD-10 CodesI66.02

I66.02

Billable

Occlusion and stenosis of left middle cerebral artery

BILLABLE STATUSYes
IMPLEMENTATION DATEOctober 1, 2015
LAST UPDATED09/06/2025

Code Description

ICD-10 I66.02 is a billable code used to indicate a diagnosis of occlusion and stenosis of left middle cerebral artery.

Key Diagnostic Point:

I66.02 refers to the occlusion and stenosis of the left middle cerebral artery (MCA), a critical vessel supplying blood to a significant portion of the lateral aspect of the cerebral hemisphere. Clinically, patients may present with neurological deficits such as weakness or numbness on the right side of the body, speech difficulties, and visual disturbances, depending on the extent of the occlusion. The MCA is vital for motor and sensory functions, and its compromise can lead to ischemic strokes. Disease progression may vary; some patients may experience transient ischemic attacks (TIAs) before a full stroke occurs. Diagnostic considerations include imaging studies such as CT or MRI to visualize the occlusion and assess collateral circulation. Doppler ultrasound may also be employed to evaluate blood flow. Early diagnosis and intervention are crucial to prevent irreversible damage and improve outcomes.

Code Complexity Analysis

Complexity Rating: Medium

Medium Complexity

Complexity Factors

  • Diagnostic complexity: Requires imaging and clinical correlation.
  • Treatment complexity: May involve medical management, surgical intervention, or rehabilitation.
  • Documentation requirements: Detailed clinical notes and imaging reports are essential.
  • Coding specificity: Requires precise coding to differentiate from other cerebrovascular conditions.

Audit Risk Factors

  • Common coding errors: Misidentifying the side of occlusion or failing to document clinical findings.
  • Documentation gaps: Incomplete records regarding patient history or imaging results.
  • Billing challenges: Potential denials due to lack of supporting documentation or incorrect coding.

Specialty Focus

Medical Specialties

Neurology

Documentation Requirements

Standard ICD-10-CM documentation requirements apply

Common Clinical Scenarios

Various clinical presentations within this specialty area

Billing Considerations

Follow specialty-specific billing guidelines

Interventional Radiology

Documentation Requirements

Standard ICD-10-CM documentation requirements apply

Common Clinical Scenarios

Various clinical presentations within this specialty area

Billing Considerations

Follow specialty-specific billing guidelines

Related ICD-10 Codes

Related CPT Codes

CPT Code

Clinical Scenario

Documentation Requirements

CPT Code

Clinical Scenario

Documentation Requirements

ICD-10 Impact

Diagnostic & Documentation Impact

Enhanced Specificity

ICD-10 Improvements

The clinical significance of I66.02 is profound, as it can lead to significant morbidity and mortality if not addressed promptly. The population health impact includes increased healthcare utilization due to emergency interventions and rehabilitation services. Quality measures focus on timely diagnosis and treatment to minimize the risk of stroke. Epidemiologically, the prevalence of cerebrovascular diseases highlights the importance of awareness and management of risk factors associated with MCA occlusion.

ICD-9 vs ICD-10

The clinical significance of I66.02 is profound, as it can lead to significant morbidity and mortality if not addressed promptly. The population health impact includes increased healthcare utilization due to emergency interventions and rehabilitation services. Quality measures focus on timely diagnosis and treatment to minimize the risk of stroke. Epidemiologically, the prevalence of cerebrovascular diseases highlights the importance of awareness and management of risk factors associated with MCA occlusion.

Reimbursement & Billing Impact

Reimbursement considerations may vary based on the severity of the condition and the treatment provided. Common denials can occur if documentation does not clearly establish the diagnosis or if the procedure codes do not align with the diagnosis. Best practices include ensuring all clinical notes are detailed and that imaging results are readily available to support the claim.

Resources

Clinical References

  • •
    ICD-10 Official Guidelines for I00-I99
  • •
    Clinical Documentation Requirements

Coding & Billing References

  • •
    ICD-10 Official Guidelines for I00-I99
  • •
    Clinical Documentation Requirements

Frequently Asked Questions

What specific conditions are covered by I66.02?

I66.02 covers occlusion and stenosis of the left middle cerebral artery, which may result from atherosclerosis, embolism, or other vascular diseases leading to ischemic events. It is crucial to differentiate it from other cerebrovascular diseases.

When should I66.02 be used instead of related codes?

I66.02 should be used specifically when the occlusion or stenosis is confirmed in the left MCA, as opposed to other codes that may refer to different arteries or unspecified occlusions.

What documentation supports I66.02?

Documentation should include imaging results confirming the occlusion or stenosis, clinical notes detailing the patient's symptoms, and any relevant history of cerebrovascular disease or risk factors.