Summary & Overview
CPT 94728: Pulmonary Function Test for Airway Resistance
CPT code 94728 denotes a noninvasive pulmonary function test that measures airway resistance using sound waves. This physiologic test is used to quantify airway mechanics and can aid diagnosis and management of obstructive and restrictive lung disease, preoperative respiratory assessment, and monitoring of treatment response. Nationally, consistent coding for PFTs like 94728 matters for clinical documentation, quality measurement, and correct claims processing across commercial and public payers.
Key payers commonly involved in coverage decisions and claims for this service include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Coverage policies and documentation requirements vary by payer and by site of service, affecting authorization, bundling, and reimbursement pathways.
Readers will learn the clinical context for CPT code 94728, typical sites where the test is performed, and which payers commonly cover the service. The publication also outlines benchmarks and billing considerations relevant to payers and providers, highlights recent policy clarifications where available, and summarizes related code groupings for pulmonary function testing. Data not available in the input will be noted as such in the detailed sections.
Billing Code Overview
CPT code 94728 describes a pulmonary function test (PFT) that measures airway resistance using sound waves. The procedure evaluates airflow and resistance in the respiratory tract by applying acoustic or sound-based plethysmography techniques to assess airway mechanics.
Service type: Pulmonary function testing (noninvasive physiologic testing)
Typical site of service: Hospital outpatient department, pulmonary function laboratory, ambulatory clinic, or specialized respiratory testing center
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Clinical & Coding Specifications
Clinical Context
A 55-year-old patient with a history of chronic obstructive pulmonary disease (COPD) and progressive dyspnea is referred to pulmonary function testing to assess airway resistance and monitor response to bronchodilator therapy. The patient arrives at an outpatient pulmonary laboratory where a respiratory therapist explains the test, reviews contraindications (recent eye/ear surgery, active hemoptysis, recent myocardial infarction), and obtains informed consent. Baseline vital signs and bronchodilator withholding instructions are confirmed. The provider orders impulse oscillometry to measure airway resistance and reactance; the patient sits quietly with a mouthpiece and nose clip while tidal breathing is recorded for several breaths. The respiratory therapist ensures proper technique and repeats maneuvers as needed for reproducibility. Results are sent to the ordering pulmonologist for interpretation; findings may prompt medication adjustment, further PFTs (spirometry, lung volumes), imaging, or referral for specialty care. Typical site of service is an outpatient pulmonary function laboratory or hospital outpatient department. The service type is diagnostic pulmonary function testing using oscillometry (airway resistance assessment).
Coding Specifications
| Modifier | Description | When to Use |
|---|---|---|
26 | Professional component | Use when billing only the physician interpretation component separate from technical service |