Summary & Overview
HCPCS G8600: IV Thrombolytic Therapy Within 4.5 Hours of Last Known Well
HCPCS Level II code G8600 denotes intravenous thrombolytic therapy initiated within 4.5 hours (≤ 270 minutes) of time last known well for patients with acute ischemic stroke. Timely reperfusion therapy is a critical element of acute stroke care, with implications for patient outcomes, hospital workflows, and payer coverage policies. Nationally, the use of time-sensitive thrombolysis is a priority for quality measurement and emergency stroke systems of care.
Key payers included in this analysis are Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find a concise overview of the code’s clinical intent, typical settings where the service is provided, and the payers commonly involved in coverage. The publication outlines what clinicians, hospital billing teams, and policy analysts need to know about billing context, expected sites of service, and the clinical window defining this code.
This summary provides benchmarks and policy-relevant context for acute stroke thrombolytic administration, highlights common billing considerations, and summarizes areas where payer policies may affect service documentation and claims processing. Data not available in the input is noted where applicable.
Billing Code Overview
HCPCS Level II code G8600 represents intravenous thrombolytic therapy initiated within 4.5 hours (≤ 270 minutes) of time last known well. This service is the acute administration of an IV thrombolytic agent for eligible patients presenting with signs of acute ischemic stroke within the specified treatment window.
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Service type: Emergency acute stroke thrombolytic therapy
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Typical site of service: Emergency department or inpatient acute care setting
Clinical & Coding Specifications
Clinical Context
A typical patient scenario is an adult who presents to the emergency department with acute onset focal neurologic deficits (for example, sudden right-sided weakness and expressive aphasia) and a clearly documented time when the patient was last known well. Prehospital or ED triage initiates a rapid stroke evaluation: emergent noncontrast head CT to exclude intracranial hemorrhage, point-of-care glucose, vital signs, and NIH Stroke Scale assessment. Laboratory tests (including coagulation studies and basic metabolic panel) and an ECG are obtained concurrently. If CT shows no hemorrhage, the patient meets inclusion criteria and no absolute contraindications to IV thrombolysis are identified, and the time from last known well to expected bolus is within 270 minutes (4.5 hours), the treating team orders and administers IV alteplase (thrombolytic therapy) in the ED or an acute stroke unit. Documentation includes precise last-known-well time, time of CT interpretation, time of consent (if obtained), time alteplase bolus start, total dose given, and monitoring plan. Typical sites of service are emergency department, hospital inpatient unit, or an acute stroke unit; care often involves neurology/stroke team consultation and admission for post‑thrombolysis monitoring and imaging.
Coding Specifications
| Modifier | Description | When to Use |
|---|---|---|
22 | Increased procedural services | Use when complexities of thrombolysis administration require substantially greater resources than typical (extensive consent or complicated dosing adjustments). |