Summary & Overview
CPT 84155: Total Protein Quantitation in Serum, Plasma, or Whole Blood
CPT code 84155 represents the technical component of a quantitative laboratory assay for total protein in serum, plasma, or whole blood, excluding refractometry. Total protein measurement is a common, low-complexity clinical chemistry test used across inpatient and outpatient settings to assess hydration, nutritional status, and organ function. Nationally, this code underpins routine metabolic panels and targeted diagnostic workups, making it relevant to laboratories, hospitals, payers, and clinicians.
This analysis covers major national payers including Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find a concise clinical context for the assay, typical sites of service, and an overview of billing considerations tied to the technical component of laboratory testing. The publication summarizes standard service lines, common billing modifiers in scope, and related administrative topics.
Readers will learn the clinical purpose of the test, the operational setting where it is commonly performed, and the payers most commonly involved in coverage. Data not available in the input will be noted where applicable. The focus is national in scope and intended to inform laboratory managers, billing specialists, and policy analysts about the role and billing identity of CPT code 84155.
Billing Code Overview
CPT code 84155 reports the technical component of a laboratory procedure to quantitate total protein in a serum, plasma, or whole blood specimen using chemical or enzymatic assay methods (refractometry excluded). The test measures the aggregate concentration of major blood proteins and provides clinical information on hydration status, nutritional state, liver and kidney function, and other systemic conditions.
Service type: Clinical laboratory — quantitative chemistry test (technical component)
Typical site of service: Clinical laboratory or hospital laboratory
Data not available in the input.
Clinical & Coding Specifications
Clinical Context
A 62-year-old outpatient presents to the primary care clinic with progressive lower extremity edema and fatigue. The clinician orders routine laboratory studies including a basic metabolic panel, complete blood count, and a serum total protein to evaluate for possible hypoproteinemia or hyperproteinemia contributing to edema and volume status changes. A phlebotomist draws a serum specimen which is sent to the hospital central laboratory. The lab analyst performs 84155 to quantitate total protein using a biochemical assay method (e.g., biuret) excluding refractometry. Results are reported in g/dL and reviewed by the ordering provider to assess nutritional status, liver synthetic function, and potential paraproteinemia as part of the diagnostic workup. Typical site of service is an outpatient clinic or hospital laboratory; the service type is a clinical laboratory quantitative chemistry test performed by the technical component of the laboratory.
Coding Specifications
| Modifier | Description | When to Use |
|---|---|---|
26 | Professional component | Use when reporting only the professional component for a lab test when applicable (rare for waived or automated chemistry tests). |
TC |