Pathology/Lab Coding Alert

Question: I have received remittance advice that CPT 87522 requires a modifier when listed with 83891, 83894, 83901, 83902 and 83912. Would that require modifier -59, or a different modifier? Ive also received an error message that if 83519 and 83520 are listed together, they require a modifier. Which modifier is that? 

Ohio Subscriber

Answer: The code pairs you listed are part of Medicares Correct Coding Initiative (CCI) edits, which were put in place to identify two types of coding errors. The first type of error is unbundling, or breaking down a single comprehensive procedure into its component parts and billing for additional services. The second is reporting together mutually exclusive procedures, which are tests or procedures that would not reasonably be performed for the same patient by the same physician on the same day.

CCI considers the first set of code pairs you mentioned to be comprehensive (87522) and component (83891-83912) codes. Code 87522 (infectious agent detection by nucleic acid [DNA or RNA]; hepatitis C, quantification) reports a molecular diagnostic technique for quantifying hepatitis C virus (HCV). The component codes describe procedures used in molecular diagnostic testing for a variety of diseases. Each component code represents a step in the overall process rather than a definitive test for a specific condition. The codes describe extraction of nucleic acid (83891), gel electrophoresis (83894), amplification (83901), reverse transcription (83902) and interpretation and report (83912). These codes are generally used for genetic studies and do not fit the classification of the detection of an infectious agent.

However, because some of the steps for infectious-agent detection by DNA or RNA technique (87470-87801) are similar to the procedures described by 83891-83912, coders may incorrectly suppose that each step should be reported using the codes for molecular diagnostics. In fact, when these tests for molecular diagnostic tests are used as steps in the procedure for identifying hepatitis C infection, it is incorrect to report each of the steps separately, because the comprehensive procedure has its own code (87522). If a coder used modifier -59 to report 87522 with 83891, 83894, 83901, 83902 and 83912 for HCV testing and received payment, the lab would be subject to a serious overpayment liability.

But, if one or more of the molecular diagnostic procedures is carried out for some purpose not related to the HCV test, such as evaluation of any of a number of genetic disorders, the codes should be reported together. Tests for these disorders may require from four to six of the molecular-diagnostics codes in the range of 83890-83912. That is when modifier -59 (distinct procedural service) should be used, indicating that two separate procedures (one for HCV and one for a distinct genetic disorder) were carried out.

Codes 83519 (immunoassay, analyte, quantitative; by radiopharmaceutical technique [e.g., RIA]) and 83520 (immunoassay, analyte, quantitative; not otherwise specified) are mutually exclusive code pairs in the CCI edits. Both of these codes report specific antigen/antibody reactions to identify and quantify the presence of a specific chemical substance (other than infectious agents). The only difference between the two codes is the method: 83519 reports radio-immunoassay technique, while 83520 reports any other immunoassay technique. The codes are considered mutually exclusive because HCFA (now CMS) considers it highly unlikely that a lab would test for the same thing using two different methods.

But CCI allows these codes to be reported with a modifier to override the edit if both procedures really are carried out for the same patient on the same day. This is sometimes done when testing for multiple components using both RIA and EIA (enzyme immunoassay) techniques. Again, use modifier -59 to indicate that two distinct procedures were carried out.

-- Answers to You Be the Coder and Reader Questions reviewed by William Dettwyler, MT-AMT, coding analyst for Health Systems Concepts, laboratory coding and compliance consultants in Longwood, Fla.