Area code 610 serves southeastern Pennsylvania, including cities such as Allentown, Bethlehem, and Reading. Introduced in 1994 as a split from area code 215, 610 covers a region rich in American industrial history and suburban development. It serves both the Lehigh Valley and parts of Philadelphia’s outer metro area. The code is associated with regional business hubs, historical communities, and local educational institutions. Ten-digit dialing is required due to overlay area code 484. 610 remains a strong regional identifier in eastern Pennsylvania.