2025 CPT code 80438
(Active) Effective Date: N/A Revision Date: N/A Laboratory - Evocative/Suppression Testing Procedures Pathology and Laboratory Procedures Feed
Thyrotropin-releasing hormone (TRH) stimulation panel; 1 hour.This includes three thyroid-stimulating hormone (TSH) measurements (84443 x 3).
Modifiers may be applicable depending on the circumstances of service. Consult the appropriate modifier guidelines.
Medical necessity for this test is established when there is clinical suspicion of hypothyroidism, particularly to differentiate between primary (thyroid gland issue), secondary (pituitary issue), and tertiary (hypothalamic issue) causes. It is also used to monitor treatment response in patients receiving thyroid hormone replacement.Specific payer policies should be consulted.
The clinical responsibility lies with the laboratory analyst who performs the technical aspects of the test: drawing blood samples, performing the TSH assay, and analyzing the results. The interpreting physician then uses these results within the context of the patient's clinical presentation to make a diagnosis.
- Pathology and Laboratory Procedures
- Pathology and Laboratory Procedures > Evocative/Suppression Testing Procedures
In simple words: This blood test checks how well your pituitary gland (a gland in your brain that controls hormones) responds to a hormone called TRH.It involves three blood draws: one before and two after a small injection of TRH to see how your TSH levels (a hormone controlling thyroid function) change over an hour.
This CPT code, 80438, represents a one-hour thyrotropin-releasing hormone (TRH) stimulation panel.The test involves measuring serum thyroid-stimulating hormone (TSH) levels at three time points: a baseline measurement before TRH administration, and two subsequent measurements at specific intervals (typically 30 minutes apart) after intravenous administration of TRH. The procedure assesses the pituitary gland's response to TRH, providing insights into thyroid function and potentially aiding in the diagnosis of hypothyroidism.
Example 1: A patient presents with symptoms suggestive of hypothyroidism (fatigue, weight gain, cold intolerance). The physician orders a TRH stimulation test to assess pituitary function and rule out secondary or tertiary hypothyroidism., A patient is undergoing thyroid hormone replacement therapy.The TRH stimulation test helps monitor the effectiveness of therapy and adjust medication dosages as needed., A patient has an elevated TSH level, but normal T4 and T3 levels, causing diagnostic uncertainty. The TRH stimulation test further investigates pituitary responsiveness and aids in the differential diagnosis.
Patient demographics, date and time of each blood draw, administration of TRH (dose and route), method of TSH assay, and all results including the time of each TSH measurement. Clinical indication for the test and relevant patient history should also be documented.
** The specific time intervals for blood collection after TRH administration may vary based on laboratory protocols and physician preference. Always adhere to the specific instructions provided by the ordering physician and the performing laboratory.
- Revenue Code: T1H (LAB TESTS - OTHER (NON-MEDICARE FEE SCHEDULE))
- Payment Status: Active
- Modifier TC rule: A Technical Component (TC) modifier is not applicable to this code as it represents a complete laboratory test panel.
- Specialties:Endocrinology, Internal Medicine
- Place of Service:Office, Hospital, Clinical Laboratory