Medicare Part A and Part B MAC for Jurisdiction 14; comprised of Colorado, New Mexico, Oklahoma and Texas. TrailBlazer data analysis of billing HCPCS code G0431 identified payment errors of qualitative drug screens. Multiple units are being billed on a single date of service when the updated code description for 2011 should be reported once per specimen. HCPCS G0431 is used by providers when billing for drug screening, most commonly in the hospital outpatient setting. TrailBlazer plans to initiate prepay review of G0431 effective April 16, 2012.