CPT code 80400 denotes the ACTH stimulation test, a key diagnostic procedure used by endocrinologists to evaluate adrenal gland function by measuring cortisol response to synthetic adrenocorticotropic hormone. Nationally, this test matters for accurate diagnosis of adrenal insufficiency and related endocrine disorders, impacting treatment decisions and follow-up care.

Key payers referenced in this analysis include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. The publication summarizes clinical context, common sites of service, and payer coverage considerations where available. Readers will find succinct benchmarks and service descriptions, clinical indications for ordering an ACTH stimulation test, and a summary of relevant billing and coding considerations tied to this CPT code. Where payer-specific coverage details are not available, the text notes that the input did not include those data.

This resource is intended to provide clinicians, billing professionals, and policy analysts with a concise national overview of CPT code 80400, its clinical role, typical service settings, and what to expect when documenting and reporting this endocrine diagnostic test.