Significant events for area code 717
| Date |
Details |
| 1947 | One of the four original area codes for Pennsylvania. It covered the east central and northeastern parts of the state. |
| December 5, 1998 | Area code 717 was split with 570 covering the northeastern area of the state. |
| August 26, 2017 | Area code 223 was overlaid on 717. |