Area code 518

Area code 518 is a telephone area code in eastern upstate New York, established as one of the original area codes in 1947. It covers 24 counties and 1,200 ZIP codes. It has 493 landline and 100 wireless exchanges serviced by 47 carriers. It is the largest area code in size in New York, extending from the eastern Mohawk Valley to the Vermont border, and from the Canada–US border to south of Albany. The bulk of the area code's population is in the Capital District (Albany, Schenectady, and Troy). Other major cities in the area code are Glens Falls and Plattsburgh.

518 is the only one of New York's original five NPAs that still has its original boundaries. Despite the presence of the Capital District and the proliferation of cell phones and pagers (particularly in the Capital District and Glens Falls), it was one of the few remaining original area codes (not counting those serving an entire state) that had never been split or overlaid. By the spring of 2016, however, 518 was on the verge of exhaustion, and it was projected that the region would need another area code by at least 2019. By the fall, however, it was anticipated that 518 would exhaust in the third quarter of 2017. An overlay area code, 838, was quickly approved, to be implemented in the fall of 2017.