Summary & Overview
CPT 84165: Serum Protein Electrophoresis (SPE/SPEP)
CPT code 84165 represents serum protein electrophoresis (SPE/SPEP), a laboratory procedure that fractionates and quantifies serum proteins to help diagnose conditions such as multiple myeloma, liver and kidney disease, and immune disorders. Nationally, SPEP is an important diagnostic tool that guides further testing and treatment decisions in hematology, nephrology, and hepatology care pathways. The code captures the technical laboratory performance of the electrophoretic separation and quantitation.
Key payers referenced in this analysis include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find an overview of clinical context, typical sites of service, and common billing modifiers associated with laboratory technical services. The publication summarizes what payers commonly cover for laboratory diagnostic testing and highlights operational considerations relevant to labs and clinicians who order and perform SPEP.
This report also outlines the clinical indications that drive SPEP utilization and describes where CPT code 84165 fits within diagnostic workflows. Data gaps in the input are noted as "Data not available in the input." The focus is national in scope and intended for billing managers, laboratory directors, and clinical stakeholders seeking a concise reference on this laboratory billing code.
Billing Code Overview
CPT code 84165 describes serum protein electrophoresis (SPE/SPEP) performed by a laboratory analyst to separate and quantitate serum protein components. The electrophoretic fractionation pattern assists clinicians in diagnosing conditions such as plasma cell disorders and other hematologic malignancies, liver disease, kidney disease, and immune system disorders.
Service type: Clinical laboratory diagnostic test (serum protein electrophoresis, technical component)
Typical site of service: Clinical laboratory or hospital outpatient laboratory
Data not available in the input.
Clinical & Coding Specifications
Clinical Context
A 62-year-old outpatient with progressive fatigue, unexplained weight loss, and an elevated total protein on basic metabolic panel is referred for serum protein electrophoresis. The clinician orders 84165 to fractionate and quantitate serum protein components to detect monoclonal gammopathy, evaluate suspected multiple myeloma, assess chronic liver disease with abnormal albumin/globulin ratio, or investigate renal protein loss. The typical workflow: the provider places an order for 84165 in the electronic health record, the patient presents to the outpatient phlebotomy or hospital laboratory, a venous blood sample is collected and processed, the laboratory analyst performs serum protein electrophoresis (SPEP) using electrophoretic separation and densitometry to quantitate fractions (albumin, alpha, beta, gamma), the lab issues a report with fraction percentages and M‑protein characterization, and the ordering clinician interprets results in the context of clinical findings and may order reflex testing (immunofixation, quantitative immunoglobulins) as indicated.
Coding Specifications
| Modifier | Description | When to Use |
|---|---|---|
26 | Professional component | Use when reporting only the professional interpretation portion if applicable and billable separately from the technical lab component. |