In early 2013, four clusters of human Salmonella infections were identified through PulseNet, the national molecular subtyping network for foodborne bacteria. Many of the ill persons in these four clusters reported contact with live poultry, primarily chicks and ducklings, from a single mail-order hatchery; therefore, these investigations were merged. During March 4-October 9, 2013, a total of 158 persons infected with outbreak strains of Salmonella serotypes Infantis, Lille, Newport, and Mbandaka were reported from 30 states.