Summary & Overview
CPT 80163: Free Digoxin Blood Level
CPT code 80163 represents a laboratory assay for free digoxin in the blood, a diagnostic test used in therapeutic drug monitoring for patients treated with digoxin for congestive heart failure or rate control. Measuring free digoxin can be important when clinicians need to assess the pharmacologically active fraction of the drug, particularly in complex clinical situations where protein binding or interactions may alter total levels. Nationally, accurate reporting and consistent billing for drug level assays support clinical decision-making and claims processing across payers.
Key payers covered in this analysis include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find a concise explanation of what the code represents, the typical clinical contexts for ordering the test, and the usual site of service. The publication summarizes payer coverage considerations, common modifiers that appear on laboratory service lines, and the clinical rationale for measuring free versus total digoxin. Additionally, readers will receive guidance on benchmarking elements and policy update highlights when available. Data not available in the input is explicitly noted where applicable.
Billing Code Overview
CPT code 80163 describes a laboratory measurement of free digoxin concentration in a patient’s blood. Digoxin is a cardiac glycoside used to treat congestive heart failure and to control heart rate in certain arrhythmias. The test quantifies the unbound (free) fraction of digoxin, which can be clinically relevant when total drug levels may not reflect active circulating drug.
Service type: Therapeutic drug monitoring / clinical laboratory test
Typical site of service: Clinical laboratory or hospital laboratory
Data not available in the input.
Clinical & Coding Specifications
Clinical Context
A 72-year-old patient with a history of chronic heart failure and atrial fibrillation presents for routine therapeutic drug monitoring after a recent change in digoxin dosing. The ordering provider is a cardiologist who requests a serum digoxin level to assess for therapeutic range and potential toxicity given symptoms of nausea, visual changes, and bradycardia. A phlebotomist draws a blood sample in the outpatient laboratory or ambulatory clinic; the sample is processed by the laboratory and the lab analyst performs an assay to measure the concentration of free digoxin in the blood (80163). Results are reported to the ordering provider and documented in the patient’s chart. Typical sites of service include hospital laboratories, independent outpatient laboratories, and ambulatory care clinics. The clinical workflow includes specimen collection, transport to the lab, analytic measurement, verification by a laboratory technologist, and result reporting to the ordering clinician for medication management decisions.
Coding Specifications
| Modifier | Description | When to Use |
|---|---|---|
26 | Professional component | Use when reporting only the professional interpretation component if applicable (rare for this lab test). |
TC |