Area codes 223 and 717

Area codes 717 and 223 are telephone area codes which serve South Central Pennsylvania and the Susquehanna Valley. They cover the Harrisburg, Lancaster and York metropolitan areas as well as most of the area generally known as Pennsylvania Dutch Country--covering an area of nearly two million people.

The main area code, 717, was one of the original area codes established in 1947. It originally covered the eastern half of the state except for the Delaware and Lehigh valleys, which were in area code 215. 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 616.

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. As a result, 717 remained unchanged for 41 years. For nearly all of this time, it was the largest numbering plan area on the Eastern Seaboard. It was pushed slightly eastward in 1994 as part of the split of Philadelphia's 215, when a few towns in eastern Lancaster County and western Chester County that were slated to transfer to area code 610 were instead shifted to 717.

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