Pathology/Lab Coding Alert

Question: How should we code the N-terminal pro-BNP test if a physician requests that test instead of BNP?

Ohio Subscriber

Answer: Either assay -- for brain natriuretic peptide (BNP) or N-terminal proBNP (NT proBNP) -- takes the same code: 83880 (Natriuretic peptide).

Although initially isolated from brain tissue, the ventricles primarily produce B-type, or brain, natriuretic peptide. The BNP molecule results from cleavage of the precursor amino acid (proBNP) into two molecules: BNP and NT-proBNP.

Many physicians prefer the BNP test because, although NT-proBNP has a longer half-life in the blood, kidney function can complicate the NT-proBNP results interpretation. Regardless of which test the lab performs, you should list 83880.

Watch for medical necessity: Physicians regularly test for natiuretic peptide when monitoring a heart condition. For instance, if the patient's BNP level goes up,the heart condition is getting worse; decreased levels means the condition is improving. Physicians also use BNP testing to determine if a patient's symptoms are due to congestive heart failure or chronic obstructive pulmonary disease. An ICD-9 code for any of these heart conditions, such as 428.x (Heart failure) or 404.x (Hypertensive heart and chronic kidney disease), should show medical necessity for the test.