Pathology/Lab Coding Alert

Question: What is the correct way to bill for a pregnancy-associated plasma protein-A (PAPP-A) for prenatal genetic screening? The test our lab performs is a radiopharmaceutical immunoassay. Should we use a generic "method" code, or is there a specific code for this test?


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Answer: CPT 2005 lists a new, specific code that you should use to bill for the PAPP-A test for prenatal screening. The code is 84163 (Pregnancy-associated plasma protein-A). Physicians frequently order this test to identify women at high-risk of carrying a fetus with Down's syndrome, trisomy 18, or other chromosomal abnormalities.

Before CPT added the new code this year, you had to use a nonspecific code that described the lab method. In your case, you should have reported PAPP-A as 83519 (Immunoassay, analyte, quantitative; by radiopharmaceutical technique [e.g., RIA]). Labs may perform the test using other methods, such as enzyme immunoassay (EIA). Although in the past, labs using EIA would have reported PAPP-A using a different code, labs should now report PAPP-A by any method using new code 84163.