What state is the 415 area code?

North American area code +1 415 is San Francisco CA and most of Marin County, plus a small part of San Mateo County.

Effective March 21, 2015, area code 628 will be added as an overlay on 415, serving the same communities. Existing telephone numbers in area code 415 will not change; however, you will have to dial 1+area code+number for all calls to, from, or within the 415/628 area.