November 9, 2016, the Pennsylvania Public Utility Commission (PUC) approved a plan to implement an overlay for the 16-county region in Central Pennsylvania served by the 717 area code by adding 223.
The new area code numbers will be assigned to new telephone numbers once the available supply of numbers in the current 717 area code are exhausted. New area codes are needed when existing area codes exhaust their supply of “NXX” codes (which is the second set of three digits in a 10-digit telephone number, NPA-NXX-XXXX).
Based on current forecast predictions, the supply of phone numbers available in the 717 area code is projected to exhaust by the third quarter of 2017.
In addition, telephone numbers for the 215/267 area code near Philadelphia are expected to be exhausted in the second quarter of 2018 and the PUC has authorized another area code overlay there too.