Area codes 717 and 223

It stretched from the Maryland border to the south to the New York and New Jersey borders, making it the largest of Pennsylvania's original four plan areas and the second-largest east of the Mississippi River that did not cover an entire state, after Michigan's area code 616.

[citation needed] Despite the presence of five of the state's 15 largest cities (Harrisburg, Lancaster, York, Scranton, and Wilkes-Barre), this part of Pennsylvania is not as densely populated as the Delaware and Lehigh Valleys.

[citation needed] By the mid-1990s, 717 was on the brink of exhaustion due to the proliferation of cell phones, pagers, and fax machines, particularly in Harrisburg, Lancaster, York, and Scranton/Wilkes-Barre.

On December 5, 1998, the northern portion of the old 717 territory, centered on Scranton, Wilkes-Barre, and Williamsport, received area code 570.

Most of those who testified in a public hearing supported an overlay as a cost-effective solution that would have spared customers the expense and burden of changing their numbers.

Area code 717 Area code 716 Area code 585 Area code 607 Area code 845 Area codes 973 and 862 Area code 908 Area codes 410 and 443 Area code 302 Area codes 240 and 301 Area codes 304 and 681 Area codes 330 and 234 Area code 440 Area code 724 Area code 878 Area code 724 Area code 814 Area codes 272 and 570 Area codes 610, 484, and 835 Area code 856 Area codes 215, 267, and 445 Area codes 609 and 640 Area codes 223 and 717 Area code 412
Pennsylvania (blue) with numbering plan area 717 shown in red.