Unbundling molecular steps means too much pay -- and costly paybacks. Every time you see DNA or RNA in a code, you don't need to rush to the CPT molecular diagnostics section. With changes to those codes in CPT 2009, now is a good time to remember when you should -- and should not -- use molecular diagnostics codes 83890-83914. Beware of Double-Dipping Although some of the procedures are similar, be careful not to confuse infectious agent detection assays with molecular diagnostics. When a lab uses methods such as DNA extraction or probe technique to detect a specific infectious agent, you should report the service with the specific code from the microbiology section rather than the 83890-83914 series, according to Elizabeth Sheppard, HT(ASCP), senior manager, technical marketing for Ventana Medical Systems in Tucson, Ariz. For instance: The lab tests a blood specimen for a patient with suspected lyme disease using a DNA direct probe technique. Report 87475 (Infectious agent detection by nucleic acid [DNA or RNA]; Borrelia burgdorferi, direct probe technique). Don't additionally report each step using the molecular diagnostics codes, such as 83896 (Molecular diagnostics; nucleic acid probe, each). Code 87475 describes the comprehensive procedure and includes every step of the process. The National Correct Coding Initiative (CCI) bundles infectious agent and molecular diagnostics codes to ensure that you don't double-dip on these services.