Summary & Overview
CPT 78111: Plasma Volume Measurement, Multiple Sample Method
CPT code 78111 represents a diagnostic laboratory/nuclear medicine procedure for measuring plasma volume by administering a radioactive tracer and obtaining multiple post-mixing samples to calculate tracer dilution. This measurement is used in clinical settings to assess intravascular volume status, support evaluations for anemia, fluid management, and select hematologic or renal assessments. Nationally, accurate coding for specialized diagnostic procedures such as 78111 influences appropriate coverage decisions and claims adjudication across commercial and public payers.
Key payers covered in this analysis include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find an explanation of the clinical context for plasma volume measurement, typical sites of service, and the service type. The publication provides benchmark-oriented coverage discussion and coding considerations relevant to payers listed above, plus summaries of typical billing modifiers and administrative issues. It also outlines common clinical indications for ordering the test and operational notes on how the multiple sample method differs from single-sample alternatives.
This summary is written for a national audience and aims to clarify what CPT code 78111 denotes, why it matters for clinical and payer workflows, and what readers should expect when reviewing coverage and billing practices for specialized plasma volume studies.
Billing Code Overview
CPT code 78111 describes a laboratory procedure to determine plasma volume by introducing a known quantity of radioactive tracer into the bloodstream and measuring its concentration after adequate mixing using a multiple sample method. This test quantifies a blood component (plasma) and is categorized as a diagnostic nuclear medicine / clinical laboratory procedure.
Service type: Diagnostic laboratory / nuclear medicine plasma volume measurement
Typical site of service: Hospital outpatient department, hospital inpatient setting, or specialized diagnostic imaging/nuclear medicine laboratory
Clinical & Coding Specifications
Clinical Context
A 62-year-old male with a history of chronic kidney disease and complex fluid management is referred from nephrology for a plasma volume determination to help quantify intravascular volume status prior to planning dialysis modality and assessing need for ultrafiltration. The patient arrives fasting to the nuclear medicine outpatient clinic. The procedure workflow includes verification of orders and informed consent, review of recent medications (anticoagulants, IV fluids), and IV access placement. A measured quantity of a radiolabeled plasma tracer is injected intravenously. Multiple timed blood samples are drawn from a contralateral venous site over a defined interval after mixing to measure tracer concentration. Samples are processed by the clinical laboratory and counts are used to calculate plasma volume. Results are reviewed by the ordering nephrologist to guide volume management and dialysis planning. Typical site of service is an outpatient nuclear medicine department, hospital-based radiology or clinical laboratory area, or an ambulatory infusion center with nuclear medicine capability.
Coding Specifications
| Modifier | Description | When to Use |
|---|---|---|
26 | Professional component | When reporting only the physician interpretation/read of the plasma volume study separate from the technical service |
TC |