Area codes 209 and 350

Area codes 209 and 350 are telephone area codes in the North American Numbering Plan (NANP) for the U.S. state of California. Their service area includes the northern San Joaquin Valley and Sierra Foothills, including Stockton, Modesto and Merced.

Area code 209 was created in an area code split of area code 916 in 1958. On November 14, 1998, the southern half of this numbering plan area received the assignment of area code 559.

On October 24, 2021, 209 was transitioned to ten-digit dialing despite not being part of an overlay complex at that time. The area code had telephone numbers assigned for the central office code 988, which was designated as a nationwide three-digit dialing code for the 988 Suicide & Crisis Lifeline in 2022. This created a conflict for all NPAs with central office code 988 that still permitted seven-digit dialing, requiring all such NPAs to transition to ten-digit dialing.

On November 28, 2022, the 209 numbering plan area was assigned a second area code, 350, to form an overlay complex to address the impending central office code exhaustion in 209 from growth in telecommunication services. Network preparation was expedited without permissive dialing period, since ten-digit dialing was already in effect.