Infections caused by enteroviruses (EV) and parechoviruses (PeV), members of the Picornaviridae family, are associated with various clinical manifestations, including hand, foot, and mouth disease; respiratory illness; myocarditis; meningitis; and sepsis; and can result in death. The genus Enterovirus includes four species of enterovirus (A-D) known to infect humans, and the genus Parechovirus includes one species (A) that infects humans. These species are further divided into types, some of which are associated with specific clinical manifestations. During 2014-2016, a total of 2,967 U.S. cases of EV and PeV infections were reported to the National Enterovirus Surveillance System (NESS). The largest number of reports during that time (2,051) occurred in 2014, when a large nationwide outbreak of enterovirus D68 (EV-D68) occurred, accounting for 68% of cases reported to NESS that year (1). Reports to the National Respiratory and Enteric Virus Surveillance System (NREVSS) during 2014-2016 indicated that circulation of EV peaks annually in the summer and early fall. Because the predominant types of EV and PeV circulating from year to year tend to vary, tracking these trends requires consistent and complete reports from laboratories with the capacity to perform typing.