PCR analysis of Ixodes scapularis ticks collected in New Jersey identified infections with Borrelia burgdorferi (33.6%), Babesia microti (8.4%), Anaplasma phagocytophila (1.9%), and Bartonella spp. (34.5%). The I. scapularis tick is a potential pathogen vector that can cause coinfection and contribute to the variety of clinical responses noted in some tick-borne disease patients.