Pathology/Lab Coding Alert

Question: Our lab sometimes performs a G0431 drug screen service on the same date of service as the physician performs G0434 in the office. If the two tests screen for different drug classes, or if they don’t, how does Medicare pay if both codes are submitted for the same patient on the same day?

Tennessee Subscriber

Answer: Medicare’s Correct Coding Initiative (CCI) lists G0434 (Drug screen, other than chromatographic; any number of drug classes, by CLIA waived test or moderate complexity test, per patient encounter) as a column 2 code to G0431 (Drug screen, qualitative; multiple drug classes by high complexity test method [e.g., immunoassay, enzyme assay], per patient encounter), and assigns the edit pair a modifier indicator of “0.” That means you can’t “unbundle” the edit pair under any circumstances, and a modifier such as 59 (Distinct procedural service) won’t override the edit.

Payment: According to Medicare instruction, “If a provider submits the two codes of an edit pair, the Column One code is eligible for payment and the Column Two code is denied.” In this case, if you bill together G0434 and G0431, Medicare should pay for the G0431 service.

No recourse: Remember that you cannot use an Advance Beneficiary Notice of Noncoverage (ABN, Form CMS-R-131) to seek payment from a Medicare beneficiary when the denial is based on a CCI edit. That’s because Medicare looks at wrongfully unbundling a CCI edit as incorrect coding rather than a medical necessity issue.