This article was originally published in August 2011. The article is being republished because CSC and the N.C. Division of Medical Assistance (DMA) found that provider payments were being delayed due to these coding errors. HCPCS Codes G0430 and G0434: Effective with date of service April 1, 2011, DMA end-dated HCPCS code G0430 and replaced it with HCPCS code G0434 (Drug screen, other than chromatographic; any number of drug classes, by CLIA waived test or moderate complexity test, per patient encounter). HCPCS code G0434 should be billed per patient encounter regardless of the number of drug classes testing or the use or presence of the QW modifier on the claim. If more than one patient encounter occurs, providers should bill repeat testing with an appropriate modifier. HCPCS Code G0431: HCPCS code G0431QW was end-dated with an effective date of service April 1, 2011 but all other modifier combinations for G0431 are currently active. Providers who received claim denials for HCPCS codes G0431 or G0431QW with EOB 7747 (Exceeds one procedure per day limitation) for dates of service prior to April 1, 2010 will need to resubmit new claims for processing.