The 505 area code is used in the state of New Mexico and covers about 13 cities, including Albuquerque, Gallup and Santa Fe. Prior to 2007, the 505 area code applied to the whole state of New Mexico. Due to the need for new numbers, it was reassigned to the northwestern and central parts of New Mexico, while the rest of the state was assigned the 575 area code.
The 505 area code was originally assigned in October 1947 and remained the sole area code for the state for 60 years. The need for a new area code was discussed as early as 2000, but the initial plans to reassign area codes, particularly to Albuquerque and Santa Fe, were met with protests and death threats. Due to the volatile situation between cities and towns in New Mexico, the idea was shelved until a plan to retain telephone numbers made the addition of a new code unnecessary.
In October 7, 2007, the New Mexico Public Regulation Commission approved the split of the area code, with Albuquerque retaining the old 505 code. The complete list of cities within the area code is as follows:
- Las Vegas
- Los Lunas
- Los Alamos
- Rio Rancho
- Santa Fe