In December 2018, the Pennsylvania Department of Agriculture (PDA) and Pennsylvania Department of Health (PADOH) were notified of a New York patient with brucellosis caused by infection with Brucella abortus RB51, the live attenuated vaccine strain of B. abortus used to prevent brucellosis in cattle (1). Brucellosis is a serious zoonotic infection caused by the bacteria Brucella spp. The most common sign is fever, followed by osteoarticular symptoms, sweating, and constitutional symptoms (2). Without proper treatment, infection can become chronic and potentially life-threatening (2). The patient had consumed raw (unpasteurized) milk from dairy A in Pennsylvania.* In July 2017, Texas health officials documented the first human case of domestically acquired RB51 infection associated with raw milk consumption from a Texas dairy (3). In October 2017, a second RB51 case associated with raw milk consumption was documented in New Jersey†; the milk source was not identified at the time.