Area Code 628

California

Area code 628 serves California, primarily San Francisco, in the Pacific Time (PT) time zone. It is an overlay area code sharing territory with area code 415.

Overlay Area Code

This area code is part of an overlay region, meaning the same geographic area is served by multiple area codes. Overlay codes were introduced to meet growing demand for phone numbers without requiring existing customers to change their numbers.

This area code shares its geographic region with: area code 415 (San Francisco).

In service since: 21-Mar-2015

Learn more about overlay and split area codes →

Demographics & Economics

Total Population: 1,157,348
Population Density: 1,944 people/sq mi
above U.S. average (U.S.: 93 people/sq mi)
Median Household Income: $141,446
above U.S. median (U.S.: $75,144)
Poverty Rate: 9.8%
below U.S. average (U.S.: 11.5%)
Unemployment Rate: 5.7%
above U.S. average (U.S.: 3.6%)
Education Attainment: Bachelor's Degree+
59.9%
above U.S. average (U.S.: 33.7%)
High School or Lower
17.7%

Statistics are population-weighted aggregations from Census ACS 5-year estimates. Population figures are approximate — see Sources & Methodology for details on how area code populations are derived.

See how this area code compares to all US area codes in the Statistics dashboard.

Time Zone

Pacific Time (PT)

NANPA Relief Status

According to the latest NANPA analysis (July 2026), this area code is not currently listed as exhausting within the next 36 months. No relief planning is in progress for this NPA.

Source: NANPA NPA Relief Planning Reports · See all relief planning statuses

Current Time

Pacific Time (PT)

Prefix Utilization

Geographic Coverage

State

Major Cities

San Francisco
South San Francisco
San Rafael
Novato
Mill Valley
Larkspur
San Anselmo
Tamalpais-Homestead Valley
Corte Madera
Tiburon
Fairfax
Sausalito
Kentfield
Lucas Valley-Marinwood
Brisbane
Santa Venetia
Sleepy Hollow
Ross
Belvedere
Lagunitas-Forest Knolls
Woodacre
Black Point-Green Point
Inverness
Bolinas

and 9 more cities

Area Code 628 geographic coverage map (light mode)

Demographics

The estimated population served by area code 628 is approximately 1,157,348. The population density is 1,944 people per square mile, which is higher than the national average of 93. The median household income is $141,446, which is higher than the national median of $75,144. Approximately 59.9% of adults hold a bachelor's degree or higher, compared to the national rate of 33.7%. This rate is higher than the national average. The poverty rate stands at 9.8%, which is lower than the national rate of 11.5%.

History

Area code 628 serves as an overlay for the same territory as area code 415. It was introduced in 2015 to provide additional phone number capacity for the region. It shares its territory with area code area code 415.