Summary & Overview
CPT 80428: Growth Hormone Stimulation Test, Four-Sample
CPT code 80428 denotes a four-sample growth hormone stimulation test in which a baseline blood sample and three post-stimulant samples (commonly after arginine) are collected and measured to assess pituitary growth hormone reserve. This endocrine dynamic test is important for diagnosing growth hormone deficiency or assessing abnormal growth and metabolic disorders. Nationally, accurate coding of stimulation tests affects clinical decision-making, laboratory workflows, and payer coverage determinations for specialized endocrine testing.
Key payers considered include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find a concise overview of the clinical intent and typical settings for the service, plus benchmarks and policy context relevant to laboratory reimbursement and utilization for endocrine stimulation testing. The publication outlines common billing modifiers and typical sites of service and identifies where Data not available in the input limits detailed mapping of payor-specific coverage rules, ICD-10 pairings, and related procedure codes.
This analysis helps clinicians, laboratory managers, and billing teams understand the clinical purpose of CPT code 80428, its role in diagnostic pathways for growth disorders, and the elements that commonly influence payer adjudication and administrative handling of stimulation tests.
Billing Code Overview
CPT code 80428 describes a laboratory procedure in which a lab analyst measures growth hormone (GH) levels in four blood samples: one collected before and three collected after administration of a stimulant (for example, arginine). This is a stimulation test for growth hormone used to evaluate GH reserve and diagnose disorders of growth hormone secretion.
Service type: Dynamic endocrine laboratory testing / hormonal stimulation testing
Typical site of service: Hospital outpatient laboratory, hospital outpatient clinic, or freestanding diagnostic laboratory
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Clinical & Coding Specifications
Clinical Context
A typical patient is a pediatric or adult patient referred to an endocrinology clinic for evaluation of suspected growth hormone deficiency due to short stature, poor linear growth velocity, delayed puberty, or unexplained hypoglycemia. The clinician orders a pharmacologic stimulation test using an agent such as arginine to provoke growth hormone (GH) secretion. The patient arrives to an outpatient infusion or hospital laboratory unit after appropriate pre-test preparation (fasting as indicated, review of current medications that affect GH secretion). An intravenous line is placed and a baseline blood sample is drawn. The stimulant (for example, arginine) is administered intravenously or per protocol and additional blood samples are collected at specified intervals (commonly three post-stimulation draws) to measure GH levels. A clinical laboratory analyst performs the hormone assays on four timed specimens and reports quantitative GH concentrations. Results are reviewed by the ordering endocrinologist, who integrates them with clinical findings, growth charts, and other laboratory/imaging studies to determine if GH stimulation is insufficient and to guide further management.
Coding Specifications
| Modifier | Description | When to Use |
|---|---|---|
26 | Professional component | Use when reporting only the professional interpretation component if separate from the laboratory technical component (rare for lab assays). |