Area codes 916 and 279 are California telephone area codes that serve Sacramento, the state capital, and most of its suburbs. Area code 916 was one of the first three original area codes established in California in October 1947. It originally covered most of Northern California, but area code splits have reduced its coverage to the greater Sacramento area. Area code 279 began service in March 2018 to relieve an exhausted supply of telephone numbers in the 916 area code. History Originally, the plan area covered the far northern portion of the state. In 1950, as part of a realignment of California's area codes, 916 was rotated to cover the northeastern corner of California, from the Sierra Nevada to the Central Valley. This involved changing Sacramento from area code 415 to 916. The numbering plan area was split in a flash-cut on March 1, 1959, when area code 707 was created out of the northwest portion. On November 1, 1997, it was split again. The northeastern portion, including Redding, Yreka and Mount Shasta, became area code 530, reducing the 916 numbering plan area to Sacramento and its immediate area. On the same day, Dixon was reassigned from 916 to 707. This split left 916 as the only one of the original 86 area codes that no longer covers any part of its original area. In 2017, the CPUC approved an overlay area code to take effect in 2018, as all available prefixes were expected to be allocated by December 2018. On February 9, 2017, the CPUC announced that the new overlay area code would be area code 279. The new area code began service on March 10, 2018. Towns and cities Area codes 916 and 279 encompass Sacramento and its surrounding suburbs: El Dorado County El Dorado Hills Placer County Granite Bay Lincoln Loomis Newcastle Penryn Rocklin Roseville Sacramento County Antelope Arden-Arcade Carmichael Citrus Heights Elk Grove Fair Oaks Florin Folsom Foothill Farms Gold River Isleton La Riviera Locke McClellan Park North Highlands Orangevale Parkway-South Sacramento Rancho Cordova Rancho Murieta Rio Linda Rosemont Sacramento Vineyard Walnut Grove Wilton Sutter County Pleasant Grove Yolo County Clarksburg West Sacramento See also List of California area codes List of NANP area codes North American Numbering Plan References External links List of exchanges from AreaCodeDownload.com, 916 Area Code 916 916 Northern California Telecommunications-related introductions in 1947