Pathology/Lab Coding Alert

Question: Sometimes a practitioner orders BNP and NT-proBNP for the same patient. I can’t find a code for NT-proBNP — how should I file this claim?

Texas Subscriber

Answer: The same code describes either the B-type natriuretic peptide (BNP: formerly brain natriuretic peptide) or N-terminal proBNP (NT proBNP). That code is 83880 (Natriuretic peptide).

Clinicians typically test for natriuretic peptide to monitor heart conditions, particularly as an indicator of congestive heart failure. Either BNP or NT proBNP provides similar clinical information, so clinicians typically order one or the other, not both.

ProBNP is a molecule that the ventricles of the heart secrete to help regulate fluid balance and blood pressure. Once released, enzymes break the molecule into NT-proBNP and BNP.

NT-proBNP has a longer half-life in the blood, but kidney function can complicate the interpretation of test results, so many clinicians prefer the BNP test.

Both tests: Although clinicians will typically order one test or the other, there may be a medically necessary reason to order both on the same day. For instance, if an initial NT-proBNP reading is unclear based on kidney values, the physician may order a BNP test based on those initial findings. If the lab performs both tests on the same day, you may need to use modifier 91 (Repeat Clinical Diagnostic Laboratory Test), depending on the payer.