Area codes 209 and 350

Their service area includes Stockton, Modesto, Turlock, Merced, Winton, Atwater, Livingston, Manteca, Ripon, Tracy, Lodi, Galt, Sonora, Los Banos, San Andreas, Mariposa, and Yosemite, the northern San Joaquin Valley (part of the Central Valley), and the Sierra Foothills.

On October 24, 2021, 209 was transitioned to 1+10-digit dialing despite not being part of an overlay complex at that time.

This created a conflict for all NPAs with central office codes of 988 that still permitted seven-digit dialing,[1] 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.

[2] The network preparation period was able to be expedited since ten-digit dialing was already in effect.