Area Code Atlas

Area code 209 split from 916

In 1958, area code 209 was created by splitting the southern portion of area code 916, covering cities such as Fresno, Stockton, and Modesto. This split reduced the geographic extent of 916, which now covers the northern region. The new area code 209 serves the northern San Joaquin Valley and Sierra Foothills region of Central California.

Jeopardy status declared for area code 209

Area code 209 was placed in jeopardy status due to telephone number demand exceeding forecasts, triggering special conservation measures in April 1997.

NANP-Split of 209 (California) Numbering Plan Area (NPA)

NPA 559 split from 209

Area code 559 was created on November 14, 1998, as a split from area code 209. The southern half of the 209 region, including Fresno, Madera, Kings, and Tulare counties in central California, was assigned to 559. This change was implemented to address the growing demand for telephone numbers in the central San Joaquin Valley and reduced the geographic area served by 209. A permissive dialing period was maintained until May 15, 1999.

Permissive dialing period ended for 559/209 split

The permissive dialing period allowing calls to be completed using either area code 209 or 559 ended on May 15, 1999, requiring use of the new area code 559 for the southern region.

Number pooling enforced for NPAs 209 and 559

Telephone number pooling was enforced for area codes 209 and 559 in 2002, reducing the size of number blocks allocated to carriers from 10,000 to 1,000 numbers. This conservation measure was implemented to extend the life of available numbering resources.

Mandatory 10-digit dialing implemented in Area Code 209

On October 24, 2021, Area Code 209 transitioned to mandatory 10-digit dialing. This change was required because the 988 central office code was designated as a nationwide three-digit dialing code for the Suicide & Crisis Lifeline, creating a conflict for NPAs that still permitted seven-digit dialing.

NPA 350 overlay on 209 announced

NPA 350 to Overlay NPA 209 (California)

NPA 350 overlay introduced for 209

Area code 350 was assigned on November 28, 2022, as an overlay to the 209 numbering plan area in California to address number exhaustion. The overlay was implemented without a permissive dialing period since ten-digit dialing was already in effect.

209/350 overlay launched without a permissive dialing period

Network preparation for the 209/350 overlay was expedited without a permissive dialing period because ten-digit dialing was already in effect in the region.