Disclosure Statement This article represents the consensus opinion of the Infectious Diseases Multiplex Working Group of the Clinical Practice Committee; all authors contributed equally. M.A.L. is employed by and owns stock options at Roche Molecular Systems. K.A. is employed by the University of North Carolina School of Medicine and has received honorarium from Cepheid. N.E.B. is employed by the Memorial Sloan Kettering Cancer Center and is supported by the MSK Cancer Center Support Grant/Core Grant (P30 CA008748), and is a Clinical Advisory Board member at ArcBio and Scientific Advisory Board member at Bio-Rad Laboratories and Agena Bioscience. S.M.B.-W. is employed by the University of Southern California and has received consulting honoraria from Luminex and BioFire. J.D.B. is employed by the Children's Hospital of Los Angeles and the University of Southern California, is temporarily employed as a medical reviewer for GenMark Diagnostics, worked previously as a consultant and a member of the Expert Advisory panel for Accelerate Diagnostics, and is a current consultant for BioFire Diagnostics. A.L.G. is employed by the University of Washington Medical Center and is a recipient of research grants from Merck and Gilead and has central testing contracts with Abbott. S.N.N. is employed by and owns stock options at LabCorp Seattle. D.N. is employed by Bio-Rad Laboratories. F.N. is currently employed by Karius Inc. The remaining authors have declared no related conflicts of interests.