Summary & Overview
CPT 84302: Sodium Measurement in Non-Blood Body Fluids
CPT code 84302 denotes a laboratory measurement of sodium concentration in specimens other than blood, plasma, serum, or urine, including body fluids and stool. The code is used when clinicians require electrolyte assessment from alternative specimen types to support diagnosis or management of gastrointestinal, renal, or inflammatory conditions. Nationally, accurate reporting of this type of specialized laboratory service affects claims processing, quality measurement, and appropriate data capture for clinical decision-making.
Key payers in this analysis include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find a concise overview of the clinical context for non-blood sodium testing, typical sites where the service is performed, and which payers commonly cover such lab services. The publication outlines expected billing scenarios, common modifiers and operational considerations where available, and highlights benchmark considerations where payers publish fee schedules or laboratory policies.
The report provides: (1) a technical description of the service and when it is used clinically; (2) payer coverage landscape and common administrative factors that affect reimbursement; and (3) guidance on documentation and coding clarity to ensure accurate claim submission. Data not available in the input are noted where applicable.
Billing Code Overview
CPT code 84302 describes a laboratory test performed by a lab analyst to measure the concentration of sodium in specimens other than blood, plasma, serum, or urine, such as body fluids or stool. This service captures analytic measurement of sodium where the specimen source is a non-blood body fluid.
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Service type: Laboratory quantitative electrolyte measurement on non-blood specimen
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Typical site of service: Clinical laboratory, hospital laboratory, or other certified laboratory that processes body fluid or stool specimens
Clinical & Coding Specifications
Clinical Context
A hospitalized adult patient with suspected meningitis has cerebrospinal fluid (CSF) collected via lumbar puncture. The laboratory receives a CSF specimen and performs electrolytes testing on the CSF to determine the concentration of sodium in the fluid. The result assists the clinical team in evaluating central nervous system disorders, intracranial pressure issues, and fluid-electrolyte disturbances related to neurological disease. Typical workflow: specimen receipt and verification, accessioning, centrifugation if needed, analyst-performed sodium assay on the CSF using an ion-selective electrode or equivalent platform, result verification, and reporting to the ordering clinician. Typical site of service: hospital inpatient laboratory, hospital outpatient laboratory, or specialized clinical laboratory processing non-blood body fluids. Service type: laboratory/clinical pathology analytic test for sodium in non-blood body fluids.
Coding Specifications
| Modifier | Description | When to Use |
|---|---|---|
26 | Professional component | When billing only the professional interpretation/analysis portion by a pathologist or laboratory professional separate from technical component |
52 | Reduced services |