Summary & Overview
HCPCS Level II A4618: Breathing Circuits
HCPCS Level II code A4618 designates breathing circuits — assemblies used to deliver gases and manage respiratory support during anesthesia and mechanical ventilation. Nationally, this supply code matters because it captures billable respiratory delivery equipment across inpatient, outpatient, and ambulatory surgical settings where ventilators or anesthesia machines are used. Accurate coding affects supply tracking, facility billing, and clinical documentation for perioperative and critical care services.
Key payers discussed in this analysis include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find a concise overview of how A4618 is used in clinical practice, typical sites of service, and the service type it represents. The publication also outlines common billing considerations, available benchmarks where provided, and relevant policy and coverage context that influence reimbursement for respiratory delivery equipment. Where specific payer policies or data are not provided, the report notes that input data are not available.
This summary equips billing managers, supply chain personnel, and clinical coders with the factual context for A4618, clarifying its role in respiratory and anesthesia supply billing and highlighting the areas — such as payer coverage policy and documentation requirements — that typically drive coding and payment outcomes.
Billing Code Overview
HCPCS Level II code A4618 represents breathing circuits — disposable or reusable assemblies used to deliver gases and manage respiratory support during anesthesia, ventilation, or procedural sedation. These assemblies typically include tubing, connectors, and interfaces that connect a patient to a ventilator or anesthesia machine.
Service type: Respiratory support / anesthesia delivery equipment
Typical site of service: Hospital inpatient and outpatient settings, ambulatory surgery centers, and procedural suites where mechanical ventilation or anesthesia is administered
Data not available in the input for payers, taxonomies, ICD-10 diagnoses, related codes, and service line.
Clinical & Coding Specifications
Clinical Context
Breathing circuits (HCPCS A4618) are disposable or reusable tubing assemblies and accessories used to deliver inhaled gases from ventilators, anesthesia machines, or other respiratory support devices to a patient and to return exhaled gas to monitoring or scavenging systems. A typical patient scenario involves an adult or pediatric patient requiring mechanical ventilation in an operating room, post-anesthesia care unit, intensive care unit, or procedural sedation setting. For example, a 62-year-old patient undergoing general anesthesia for abdominal surgery is intubated and connected to the anesthesia machine via a breathing circuit; the circuit provides the pathway for delivery of anesthetic gases and oxygen and allows connection of filters, heat-moisture exchangers, and end-tidal CO2 sampling lines.
Clinical workflow: the anesthesia or respiratory therapy team selects an appropriately sized breathing circuit before induction, assembles and connects the circuit to the ventilator/anesthesia machine and the endotracheal tube or mask, performs a leak and compliance check, incorporates inline filters or humidification as indicated, monitors ventilator parameters and gas sampling during the procedure, and discards or reprocesses the circuit per device and infection control policies after use. Documentation includes device description (A4618), size/type, date/time of use, associated ventilator or anesthesia machine, and disposables attached (filters, humidifiers).
Coding Specifications
| Modifier | Description | When to Use |
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