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ICD-10 Guide
ICD-10 CodesI66.1

I66.1

Non-billable

Occlusion and stenosis of anterior cerebral artery

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

Code Description

ICD-10 I66.1 is a used to indicate a diagnosis of occlusion and stenosis of anterior cerebral artery.

Key Diagnostic Point:

I66.1 refers to the occlusion and stenosis of the anterior cerebral artery (ACA), a critical vessel supplying blood to the frontal lobes and superior medial parietal lobes of the brain. Clinical presentation may include symptoms such as weakness or paralysis on one side of the body, changes in speech, and cognitive impairments, depending on the extent of ischemia. The anatomy involved includes the ACA, which branches from the internal carotid artery and is crucial for maintaining cerebral perfusion. Disease progression can lead to transient ischemic attacks (TIAs) or full-blown strokes if not addressed promptly. Diagnostic considerations include imaging studies such as MRI or CT angiography to visualize blood flow and identify occlusions or stenosis. Additionally, risk factors such as hypertension, diabetes, and hyperlipidemia should be evaluated to manage underlying conditions effectively.

Code Complexity Analysis

Complexity Rating: Medium

Medium Complexity

Complexity Factors

  • Diagnostic complexity: Requires imaging and clinical correlation to confirm diagnosis.
  • Treatment complexity: May involve medical management, surgical intervention, or rehabilitation.
  • Documentation requirements: Detailed clinical notes and imaging reports are essential.
  • Coding specificity: Requires accurate identification of the affected artery and associated conditions.

Audit Risk Factors

  • Common coding errors: Misidentification of the affected artery or incorrect use of related codes.
  • Documentation gaps: Incomplete clinical notes or lack of imaging results.
  • Billing challenges: Potential denials due to insufficient documentation or coding errors.

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

Vascular Surgery

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

CPT Code

Clinical Scenario

Documentation Requirements

ICD-10 Impact

Diagnostic & Documentation Impact

Enhanced Specificity

ICD-10 Improvements

The clinical significance of I66.1 lies in its potential to lead to severe neurological deficits if not promptly diagnosed and treated. The impact on population health is considerable, as strokes are a leading cause of morbidity and mortality. Quality measures focus on timely intervention and management of risk factors, while healthcare utilization patterns indicate a need for increased awareness and preventive strategies in at-risk populations. Epidemiologically, conditions leading to ACA occlusion are prevalent in aging populations and those with vascular risk factors.

ICD-9 vs ICD-10

The clinical significance of I66.1 lies in its potential to lead to severe neurological deficits if not promptly diagnosed and treated. The impact on population health is considerable, as strokes are a leading cause of morbidity and mortality. Quality measures focus on timely intervention and management of risk factors, while healthcare utilization patterns indicate a need for increased awareness and preventive strategies in at-risk populations. Epidemiologically, conditions leading to ACA occlusion are prevalent in aging populations and those with vascular risk factors.

Reimbursement & Billing Impact

Reimbursement considerations include the severity of the condition and the complexity of care provided. Common denials may arise from insufficient documentation or failure to demonstrate medical necessity. Best practices include ensuring that all clinical notes are comprehensive and that imaging results are clearly linked to the diagnosis to support claims.

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 I66.1?

I66.1 covers conditions related to occlusion and stenosis of the anterior cerebral artery, including ischemic strokes and transient ischemic attacks (TIAs) that affect the ACA territory.

When should I66.1 be used instead of related codes?

I66.1 should be used when there is a confirmed diagnosis of occlusion or stenosis specifically affecting the anterior cerebral artery, differentiating it from other cerebral artery occlusions.

What documentation supports I66.1?

Documentation should include clinical findings, imaging results confirming occlusion or stenosis, and any relevant patient history that supports the diagnosis.