Summary & Overview
CPT 84588: Vasopressin (Antidiuretic Hormone) Quantitative Assay
CPT code 84588 identifies a quantitative laboratory assay for vasopressin (antidiuretic hormone, ADH). The test is clinically important for diagnosing and managing disorders of water and sodium homeostasis, such as diabetes insipidus and SIADH, and has national relevance because it supports inpatient and outpatient diagnostic pathways in hospitals and reference laboratories. Payers evaluated in this analysis include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare.
Readers will find a concise overview of the procedure and its clinical context, common sites of service, and how the test fits into diagnostic workflows. The publication also covers payer coverage patterns and benchmark information where available, identifies coding and billing considerations tied to laboratory services, and summarizes relevant policy updates that affect payment and utilization. Clinical implications for patient care and typical use cases are described to inform payers, hospital billing staff, and laboratory managers. Data not available in the input is noted where applicable.
Billing Code Overview
CPT code 84588 describes a laboratory assay performed to measure the concentration of vasopressin, also known as antidiuretic hormone (ADH), in a patient specimen. The test is a quantitative measurement used to evaluate disorders of water balance and sodium regulation, including suspected diabetes insipidus, syndrome of inappropriate antidiuretic hormone secretion (SIADH), and other conditions affecting vasopressin physiology.
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Service type: Clinical laboratory diagnostic test (hormone assay)
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Typical site of service: Hospital laboratory, independent clinical laboratory, or other certified diagnostic laboratory setting
Clinical & Coding Specifications
Clinical Context
A typical patient is an adult admitted for evaluation of polyuria and polydipsia with suspected diabetes insipidus or a patient in the emergency department with severe hyponatremia and unclear volume status. The clinician orders a plasma vasopressin (antidiuretic hormone) level to help differentiate central diabetes insipidus, nephrogenic diabetes insipidus, primary polydipsia, or to assess vasopressin response during a water-deprivation/vasopressin-stimulation diagnostic sequence. Blood is drawn in the lab using appropriate preanalytical handling (ice, EDTA tube, rapid centrifugation) and sent to the clinical laboratory. The lab analyst performs the 84588 assay, typically using immunoassay or mass spectrometry depending on the laboratory’s methodology. Results are reported to the ordering clinician and interpreted in the context of serum sodium, serum osmolality, and urine osmolality. Typical sites of service include the hospital inpatient lab, emergency department, and outpatient clinical laboratory or reference lab. Common clinical workflow elements: clinician order -> specimen collection with preanalytic precautions -> transport to lab -> assay 84588 performed by laboratory personnel -> result reported to clinician -> correlation with other labs and clinical findings for diagnosis and management decisions.
Coding Specifications
| Modifier | Description | When to Use |
|---|---|---|
26 |