Locations for Area Code - 858

Area code 858 serves northwestern San Diego County, California, including communities like La Jolla, Del Mar, Rancho Bernardo, and Mira Mesa. Created in 1999 from a split with 619, it covers a region known for biotechnology, higher education, and affluent residential neighborhoods. UC San Diego and the biotech corridor in Sorrento Valley are key economic drivers. Ten-digit dialing is required. Area code 858 is a mark of distinction in the San Diego area, often associated with innovation, research, and upscale living along California’s southern coast.