Summary & Overview
CPT 84134: Prealbumin (Transthyretin) Measurement, Serum
CPT code 84134 represents the laboratory assay for prealbumin (transthyretin) measurement in patient serum. This test is clinically significant for evaluating nutritional status and monitoring short-term changes in protein stores, making it relevant across inpatient and outpatient care settings. Nationally, measurement of prealbumin informs clinical management of malnutrition, critical illness, and recovery monitoring, and it carries implications for laboratory billing and coverage determinations.
Key payers in the national landscape include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find a concise overview of the code’s clinical role and typical sites of service, followed by benchmark considerations and payer coverage patterns where available. The publication addresses how 84134 is used in clinical workflows, common billing considerations, and places the test in context with related laboratory services. Data not available in the input is noted where applicable, and policy or reimbursement updates from major payers are summarized when accessible. The content is intended for clinical laboratory managers, billing professionals, and policy analysts seeking a national-level briefing on CPT code 84134.
Billing Code Overview
CPT code 84134 describes a laboratory test in which a lab analyst measures prealbumin (transthyretin) concentration in a patient specimen, typically serum. This assay is used to assess nutritional status, monitor short-term changes in protein-calorie malnutrition, and evaluate response to nutritional interventions.
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Service type: Clinical laboratory diagnostic test
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Typical site of service: Hospital laboratory, independent clinical laboratory, or outpatient phlebotomy/diagnostic collection site
Clinical & Coding Specifications
Clinical Context
A 68-year-old hospitalized patient with recent major surgery is being monitored for nutritional status and risk of protein-calorie malnutrition. The clinician orders a prealbumin (transthyretin) measurement to assess acute changes in nutritional status and response to nutritional support. A phlebotomy technician obtains a serum specimen and sends it to the hospital clinical laboratory. The lab analyst performs the 84134 assay, documents specimen type and collection time, runs the prealbumin assay on the immunoassay or nephelometry platform, validates results per laboratory policy, and reports numeric prealbumin concentration to the ordering provider via the electronic medical record. Typical sites of service include inpatient hospital clinical laboratories, outpatient hospital labs, and independent clinical laboratories processing physician office or clinic specimens. Turnaround time is generally within hours for inpatient management. Results guide nutritional interventions, monitoring of recovery, and correlation with inflammatory states and hepatic function.
Coding Specifications
| Modifier | Description | When to Use |
|---|---|---|
26 | Professional component | Use when only the professional interpretation or oversight of the laboratory testing is billed separately from the technical component. |