80400

ACTH Stimulation Panel for Adrenal Insufficiency

The ACTH stimulation panel, identified by CPT code 80400, is a fundamental diagnostic tool in endocrinology utilized to evaluate the responsiveness of the adrenal glands to adrenocorticotropic hormone. This provocative test is the gold standard for diagnosing primary adrenal insufficiency, also known as Addison's disease. The physiological principle behind the test is that in a healthy individual, the administration of synthetic ACTH (cosyntropin) should trigger a rapid and significant increase in the production and secretion of cortisol from the adrenal cortex. The procedure begins with the collection of a baseline blood sample to measure the resting serum cortisol level. Following this, the patient is administered a pharmacological dose of cosyntropin, typically 250 micrograms, via intravenous or intramuscular injection. Subsequent blood samples are drawn at specific timed intervals, most commonly at 30 minutes and 60 minutes post-injection, to capture the peak adrenal response. A normal response is generally characterized by a peak cortisol level exceeding 18-20 mcg/dL, depending on the specific laboratory assay and clinical guidelines. A subnormal response indicates that the adrenal cortex is unable to produce sufficient cortisol, confirming a diagnosis of adrenal insufficiency. This test is also utilized to assess patients who have been on long-term exogenous corticosteroid therapy to determine if their hypothalamic-pituitary-adrenal (HPA) axis has recovered sufficiently to allow for the tapering of medications. Accurate coding of 80400 requires that both the baseline and post-stimulation cortisol levels are obtained and analyzed as part of a single clinical encounter, providing a clear picture of adrenal reserve capacity.

Clinical Indications

  • Suspected Primary Adrenal Insufficiency (Addison's Disease)
  • Evaluation of Hypopituitarism affecting the HPA axis
  • Assessment of adrenal recovery after prolonged corticosteroid therapy
  • Investigation of unexplained hypotension or electrolyte imbalances (hyponatremia, hyperkalemia)
  • Differential diagnosis of congenital adrenal hyperplasia
  • Evaluation of clinical symptoms such as hyperpigmentation and chronic fatigue

Procedure Steps

  1. Verify patient identity and ensure the patient has not taken oral glucocorticoids for at least 12-24 hours prior to testing.
  2. Collect a baseline blood sample (Time 0) for serum cortisol measurement.
  3. Administer 250 mcg of cosyntropin (synthetic ACTH) via intravenous (IV) or intramuscular (IM) injection.
  4. Wait 30 minutes post-injection and collect the second blood sample for serum cortisol measurement.
  5. Wait 60 minutes post-injection and collect the third blood sample for serum cortisol measurement.
  6. Label all samples clearly with the timing of the draw relative to the injection.
  7. Process all cortisol samples in the laboratory and compare the results to determine the peak cortisol response.

Coding Guidelines

  • CPT 80400 specifically includes two cortisol measurements (82533 x 2). If additional measurements are taken, they should be reviewed to see if they meet the criteria for separate reporting.
  • The administration of the cosyntropin is not included in the lab panel code and should be reported using the appropriate injection code (e.g., 96372 for IM or 96374 for IV).
  • The supply of the medication (cosyntropin) is reported separately using HCPCS code J0834.
  • Routine venipuncture for the collection of blood samples should be reported using CPT 36415.
  • If the panel is performed but does not include all specified components, the individual test codes (e.g., 82533) should be reported instead of the panel code 80400.
  • Do not report 80400 in conjunction with individual cortisol tests performed during the same encounter for the same stimulation event.

Associated ICD-10 Codes