All 41 California area codes
California's 41 area codes are the most of any US state, a direct result of the state's population growth outpacing three-digit-code capacity again and again since 1947. The table groups every code with its current region and the date it went into service.
All 41 California area codes
| Area code | Region | In service since |
|---|---|---|
| 209 | Stockton, Modesto, Merced, central CA | 1958 |
| 213 | Central Los Angeles | 1947 (original) |
| 279 | Sacramento metropolitan area (overlay) | Mar 10, 2018 |
| 310 | Southwestern LA County: Beverly Hills, Santa Monica | Nov 2, 1991 |
| 323 | Downtown LA and surrounding areas (overlay) | Jun 13, 1998 |
| 341 | East Bay coastal: Oakland, Fremont, Berkeley (overlay) | Jul 22, 2019 |
| 350 | Stockton, Modesto, Merced (overlay) | Nov 28, 2022 |
| 357 | Fresno, Hanford, Madera, San Joaquin Valley (overlay) | Mar 26, 2025 |
| 369 | Vallejo, Eureka, northwestern CA (overlay) | Feb 1, 2023 |
| 408 | San Jose, Silicon Valley | 1959 |
| 415 | San Francisco, Marin County | 1947 (original) |
| 424 | Southwestern LA County (overlay) | Aug 26, 2006 |
| 442 | Southeastern desert/mountain CA | Nov 21, 2009 |
| 510 | East Bay coastal: Oakland, Fremont, Berkeley | Sep 2, 1991 |
| 530 | Redding, Chico, Lake Tahoe, northeastern CA | Nov 1, 1997 |
| 559 | Fresno, Hanford, San Joaquin Valley | Nov 14, 1998 |
| 562 | Long Beach, Downey, Whittier | Jan 25, 1997 |
| 619 | San Diego and suburbs | 1982 |
| 626 | San Gabriel Valley | Jun 14, 1997 |
| 628 | San Francisco, Marin County (overlay) | Mar 21, 2015 |
| 650 | Daly City, Palo Alto, Redwood City | Aug 2, 1997 |
| 657 | Northern Orange County (overlay) | Sep 23, 2008 |
| 661 | Northern LA County, Kern County: Bakersfield | Feb 13, 1999 |
| 669 | San Jose, Silicon Valley (overlay) | Nov 20, 2012 |
| 707 | Vallejo, Eureka, northwestern CA | 1959 |
| 714 | Northern Orange County | 1951 |
| 738 | Los Angeles outside the San Fernando Valley (overlay) | Nov 1, 2024 |
| 747 | San Fernando Valley (overlay) | May 18, 2009 |
| 760 | Southeastern desert/mountain CA | Mar 22, 1997 |
| 805 | Ventura, San Luis Obispo, Santa Barbara Counties | 1957 |
| 818 | San Fernando Valley | Jan 7, 1984 |
| 820 | Ventura, San Luis Obispo, Santa Barbara (overlay) | Jun 30, 2018 |
| 831 | Monterey, San Benito, Santa Cruz Counties | Jul 11, 1998 |
| 837 | Redding, Chico, Lake Tahoe (overlay) | Jan 31, 2025 |
| 840 | SW San Bernardino County (overlay) | Feb 23, 2021 |
| 858 | San Diego and suburbs (overlay) | Jun 12, 1999 |
| 909 | SW San Bernardino, Riverside Counties | Nov 14, 1992 |
| 916 | Sacramento metropolitan area | 1947 (original) |
| 925 | East Bay inland: Livermore, Concord, Walnut Creek | Mar 14, 1998 |
| 949 | Southern Orange County: Irvine, Mission Viejo | Apr 18, 1998 |
| 951 | Western Riverside County: Riverside, Corona | Jul 17, 2004 |
Los Angeles: from one code in 1947 to six today
213 covered the entire southern third of California when it launched in 1947. Los Angeles's own growth forced five splits off of 213 over the following decades -- 714 (1951, Orange County), 805 (1957, the central coast), 818 (1984, the San Fernando Valley), 310 (1991, the southwestern coast), and 323 (1998, the rest of central LA) -- before the pattern shifted from splitting to overlaying: 424 stacked onto 310 in 2006, 747 onto 818 in 2009, and, after 213 and 323 were formally merged back into a single overlay complex in 2017, a sixth code, 738, was added on top of that combined area in November 2024.
San Francisco followed a similar but smaller path: 415 (1947) split off 408 and 707 in 1959, then 510 and 650 in the early 1990s, before finally being overlaid by 628 in 2015 once splitting stopped being an option. Sacramento took the simplest route of any major California metro -- one split-free run on 916 from 1947 all the way to 2018, when 279 was added as an overlay.