916 Area Code: Sacramento, 279 Overlay & History

The essentials

916 area code: quick facts

How 916 became Sacramento's code

The CPUC describes 916 as one of the three area codes California started with in 1947. Its territory has shrunk twice since then, and in 2018 it gained an overlay rather than losing more ground. The timeline below uses the CPUC and the FCC.

1. 1947: Area code 916 is created as one of the original three area codes in California, according to the CPUC. The FCC lists 916 as opening in January 1947.
2. 1959: 916 is split to create the 707 area code (CPUC). The FCC lists 707 as opening in January 1959.
3. 1997: 916 is split again to create the 530 area code (CPUC). The FCC lists 530 as opening in November 1997. The CPUC's June 2017 release notes that this split required some customers to change their area code.
4. October 22, 2015: After NANPA forecasts that 916 will run out of prefixes, the telephone industry meets and reaches consensus to recommend an all-services overlay, according to the CPUC decision.
5. August 15 and 16, 2016: CPUC staff hold three public meetings, in Sacramento and Folsom on August 15 and in Roseville on August 16.
6. November 17, 2016: NANPA, on behalf of the industry, files Application 16-11-007 asking the CPUC for relief in the 916 area.
7. February 9, 2017: The CPUC adopts the overlay in Decision 17-02-010, with a 13-month implementation schedule. The decision was issued on February 16, 2017.
8. August 12, 2017: Permissive dialing begins. Customers with 916 numbers may start dialing 1 + area code + number for local calls.
9. February 10, 2018: Dialing 1 + area code + number becomes mandatory for calls from 916 numbers.
10. March 10, 2018: The 279 overlay takes effect. Customers asking for new or additional numbers may be assigned 279 or 916 numbers, depending on inventory.

Where area code 916 is used

The CPUC says the 916 area code serves the greater Sacramento area, including the state capital. Its 2017 decision says the territory includes small portions of El Dorado, Solano, Sutter, and Yolo counties and much of Placer and Sacramento counties. The CPUC's 916/279 page lists the same six counties as parts of the area.

The regulator names these cities in the 916 area:

The decision describes a mix of urban and suburban cities and unincorporated residential communities. It mentions state government buildings, Sacramento International Airport, the Port of Sacramento in West Sacramento, and fishing and boating on the Sacramento River Delta, with growth areas separated by agriculture and the Delta.

The decision also says the 916 area has 16 rate centers. A rate center is a billing area, not a boundary. The CPUC lists cities, not street boundaries, and the communities in El Dorado, Solano, and Sutter counties are not named in the sources checked, so confirm a specific address with your phone provider.

Why 916 needed relief, and why an overlay was chosen

An area code has a limited supply of three-digit prefixes. The CPUC decision explains that each prefix holds 10,000 line numbers and that some prefixes, such as 211, 511, and 911, are set aside, so only 792 usable prefixes exist in an area code. By August 2, 2016, only 53 usable prefixes were left in 916, about seven percent.

NANPA's forecasts moved during the planning. The decision says a September 2015 analysis showed 916 running out of prefixes in the fourth quarter of 2018, and the April 2016 analysis moved that to the first quarter of 2018. The decision also says no conservation measures or rationing would prevent exhaust.

The industry presented two options. An all-services overlay would add a new code over the whole 916 territory and had a projected life of 36 years. A geographic split would have divided 916 into two codes with projected lives of 23 and 55 years. The CPUC said that gap of 32 years broke the industry guideline that splits should avoid a difference of more than ten years. The split would also have divided the cities of Sacramento, Rancho Cordova, Elk Grove, and Citrus Heights.

Public opinion leaned the same way. The decision says 53 of the 54 people who attended the three public meetings supported the overlay or had no objection, and an official for the City of Rancho Cordova asked the CPUC not to split the city. The CPUC concluded that an overlay was less confusing and less costly for existing customers, since nobody would need to reprint stationery or tell contacts about a new number.

NANPA's April 2026 analysis, based on data as of March 1, 2026, projects that the combined 279/916 area will run out of numbers in the second quarter of 2063. That is 25 quarters later than its previous analysis. Forecasts move from one analysis to the next, so treat the date as an estimate.

Neighboring area codes in California

The CPUC says the 916/279 area is bordered on the north and east by 530, on the west by 707, and on the south by 925 and 209. The table shows what the official sources say about each.

The CPUC sources checked describe 925 and 209 only as bordering codes. They do not say which code those areas came from, so this guide does not either.

The 279 overlay and what it changes

An overlay adds another area code to the same geographic region served by an existing one. The CPUC says 279 was added to the 916 region "to ensure a continuing supply of telephone numbers for the area." Unlike the 1997 split, the overlay did not require anyone to change an existing area code or number.

• Existing numbers: residents and businesses kept their 916 numbers and area code.
• Local calls stay local: the CPUC says dialing 1 + area code + number does not change what a call costs and does not make it a toll or long distance call.
• Who had to change dialing: everyone with a 916 number, because seven-digit local dialing ended on February 10, 2018. Customers who get 279 numbers dial the same way.
• When 279 is assigned: from March 10, 2018, a new or additional line may get a 279 or a 916 number, depending on available inventory.

The decision also explains why the dialing had to change. Federal rules say no overlay may be implemented unless ten-digit dialing is mandatory for every call within and between the area codes in the overlay area, and earlier CPUC decisions made mandatory 1+10-digit dialing a condition of approving any overlay in California. The decision adds that California landline callers already used 1+10 digits to reach another area code.

To prepare customers, the CPUC ordered a public education program, paid for by the service providers holding 916 numbers, with a goal of 70 percent customer awareness. The materials had to explain the type of change, the area covered, the permissive and mandatory dialing periods, and that the cost and quality of service would not be harmed.

The CPUC's June 2017 release says California and other states had implemented approximately 60 area code overlays across the U.S. at that point. Because 916 and 279 overlap, two neighbors on the same street can have different area codes.

Time zone and daylight saving time

Area code 916 uses Pacific Time. The tz database zone table lists the zone America/Los_Angeles with the label "Pacific." Under federal rules, the Pacific standard time zone (49 CFR 71.10) covers the continental United States west of the mountain-Pacific boundary in 49 CFR 71.9, which runs along the Nevada-Arizona and Arizona-California boundaries. California lies west of that line.

NIST says daylight saving time begins at 2:00 a.m. on the second Sunday of March and ends at 2:00 a.m. on the first Sunday of November, under rules enacted by the Energy Policy Act of 2005. The NIST page lists Hawaii, American Samoa, Guam, Puerto Rico, the Virgin Islands, and Arizona as places that do not observe it, and California is not on that list. In 2026, NIST gives March 8 and November 1 as the change dates.

How to dial a 916 number

North American numbers have three parts: a country code, a three-digit area code, and a seven-digit local number. NANPA says the ITU assigned country code 1 to the NANP area. The CPUC decision gives 916-777-0100 as an example of an area code, a prefix, and a line number.

The CPUC says calls from 916 or 279 numbers must be dialed as 1 + area code + seven-digit number. A call placed without the 1 and the area code is not completed, and a recording tells the caller to hang up and dial again. The CPUC adds that callers with certain cell phone providers may be able to complete calls without dialing the 1 first. You can still dial three digits for 911, 211, 311, 411, 511, 611, 711, and 811.

The change came in two steps. From August 12, 2017, customers could use the new pattern while seven-digit local calls still worked, which the CPUC calls permissive dialing. From February 10, 2018, the old pattern stopped working. One month later, on March 10, 2018, the first 279 numbers could be assigned. The decision set this order on purpose: new numbers with the new code could be issued only after the mandatory dialing period had started.

The CPUC advises reprogramming automatic dialing equipment, and lists life safety systems and medical monitoring devices, fax machines, Internet dial-up numbers, alarm and security systems, gates, speed dialers, call forwarding settings, and voicemail services. It also asks businesses to update stationery, business cards, advertisements, websites, and catalogs to show the full number. The CPUC dialing material is from 2017 and 2018, so confirm the current rule with your provider.

Caller ID and scams with a 916 number

The FTC warns that "Scammers can make any name or number show up on your caller ID." That is called spoofing. Scammers can also match the first six digits of your own number, which the FTC calls neighbor spoofing.

• If you pick up and do not recognize the caller, the FTC advises that you hang up.
• Letting an unknown call go to voicemail is one option.
• The FTC says call blocking is your best defense against unwanted calls.

The sources checked do not say that 916 numbers are targeted more than others. A 916 number shows the code that was assigned, not who is calling or where they are. Because 279 shares the same territory, neither code is a reliable sign of where in the Sacramento area a caller is.

Choosing a 916 number for a business

916 is Sacramento's original area code, but since March 10, 2018 the CPUC says a new or additional line may be assigned a 279 or a 916 number, depending on available inventory. A new line may carry 279 instead of 916, and the area code does not show which part of the region the business is in.

Because the two codes share territory, route calls by team or extension, not by area code. Ask your provider which code a new line gets, since that depends on its current inventory.

Whether a specific 916 number can be assigned to your business depends on your phone provider and its current inventory. This guide does not make claims about availability.

Important: Confirm availability with your provider before you plan a campaign or print a number on materials.

Before you use a 916 number

• Confirm the number is available from your provider, and get its terms in writing.
• Ask who owns the number and whether it can be moved to another provider if you switch.
• Ask whether a new line would be a 916 or a 279 number.
• Dial 1 plus the area code plus the number on every system, including PBXs, fax machines, alarms, gates, call forwarding, and voicemail, as the CPUC advises.
• Print the full number, with area code, on stationery, cards, advertising, and your website.
• Route calls by team or extension, because 916 and 279 share one territory.
• Check each site's address. The CPUC names cities and counties, not street boundaries, so confirm the address with your provider.
• Plan for caller ID. A 916 number does not prove who is calling, and neighbor spoofing copies the first six digits of your own number.

Related guides and tools

• 415 area code guide: San Francisco, another of California's 1947 area codes, for comparison with Sacramento.
• 213 area code guide: Los Angeles, the third original California code from 1947.
• 619 area code guide: San Diego, a California code that shares its region with 858.
• 408 area code guide: San Jose, another Northern California code, for comparison with Sacramento.
• 503 area code guide: Portland, another West Coast metro, for comparison with Sacramento.
• What is a DID number?: what a DID is, local versus toll-free types and porting rules.
• Business phone number porting: how number porting works, how long it takes and how to prepare.
• Full list of U.S. area codes by state, with the overlay codes and time zone for every code.
• Browse all U.S. area code guides, including overlay codes that do not have their own guide yet.
• Business phone system and call routing for local numbers in Sacramento.

Frequently asked questions