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ICD-10 Guide
ICD-10 CodesI66.12

I66.12

Billable

Occlusion and stenosis of left anterior cerebral artery

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

Code Description

ICD-10 I66.12 is a billable code used to indicate a diagnosis of occlusion and stenosis of left anterior cerebral artery.

Key Diagnostic Point:

I66.12 refers to the occlusion and stenosis of the left anterior cerebral artery (ACA), a critical vessel supplying blood to the medial portions of the frontal lobes and the superior medial parietal lobes. Clinically, patients may present with symptoms such as unilateral weakness, sensory loss, or cognitive impairments, depending on the extent of ischemia. The ACA is part of the anterior circulation of the brain, and occlusion can lead to significant neurological deficits. Disease progression may involve gradual stenosis due to atherosclerosis or acute occlusion from embolic events. Diagnostic considerations include imaging studies such as MRI or CT angiography to visualize the artery and assess blood flow. Doppler ultrasound may also be utilized to evaluate blood flow dynamics. Early diagnosis and intervention are crucial to prevent irreversible brain damage and optimize patient outcomes.

Code Complexity Analysis

Complexity Rating: Medium

Medium Complexity

Complexity Factors

  • Diagnostic complexity: Requires imaging and clinical correlation to confirm occlusion or stenosis.
  • Treatment complexity: May involve medical management, surgical intervention, or endovascular procedures.
  • Documentation requirements: Detailed clinical notes and imaging reports are essential for accurate coding.
  • Coding specificity: Requires precise documentation of the affected artery and the nature of the occlusion.

Audit Risk Factors

  • Common coding errors: Misidentification of the affected artery or incorrect laterality.
  • Documentation gaps: Insufficient clinical details or lack of imaging reports.
  • Billing challenges: Potential denials due to lack of supporting documentation or unclear clinical rationale.

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

ICD-10 Impact

Diagnostic & Documentation Impact

Enhanced Specificity

ICD-10 Improvements

The clinical significance of I66.12 lies in its association with stroke risk and potential long-term disability. Population health impact includes increased healthcare utilization due to acute care needs and rehabilitation services. Quality measures focus on timely diagnosis and intervention to minimize neurological damage. Epidemiologically, conditions affecting the anterior cerebral artery are prevalent in older populations and those with cardiovascular risk factors, highlighting the need for effective management strategies.

ICD-9 vs ICD-10

The clinical significance of I66.12 lies in its association with stroke risk and potential long-term disability. Population health impact includes increased healthcare utilization due to acute care needs and rehabilitation services. Quality measures focus on timely diagnosis and intervention to minimize neurological damage. Epidemiologically, conditions affecting the anterior cerebral artery are prevalent in older populations and those with cardiovascular risk factors, highlighting the need for effective management strategies.

Reimbursement & Billing Impact

Reimbursement considerations include the complexity of the case and the treatment provided. Common denials may arise from insufficient documentation or failure to demonstrate medical necessity. Coders should ensure that all relevant clinical information is included in the patient's record to support the use of I66.12 and related procedure codes, ensuring compliance with payer requirements.

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 I66.12?

I66.12 covers conditions related to occlusion or stenosis of the left anterior cerebral artery, including ischemic strokes and transient ischemic attacks (TIAs) affecting this vascular territory.

When should I66.12 be used instead of related codes?

I66.12 should be used when there is documented occlusion or stenosis specifically of the left anterior cerebral artery, differentiating it from other cerebral arteries or conditions.

What documentation supports I66.12?

Documentation should include clinical findings, imaging results confirming occlusion or stenosis, and any relevant treatment plans. Detailed notes on neurological assessments are also critical.