| City: | San Gabriel, California |
| County: | Los Angeles County |
| Timezone: | Pacific (GMT -08:00) |
| Local Time: | 10:10:16 PM |
| Population: | No Population Data |
| Area Code: | 626 |
| Classification: | PO Box |
| Coordinates: | 34.0962, -118.1052 |
| Quick Link: |
ZIP code 91778 exists solely for PO Box service at the San Gabriel post office. It doesn't cover any geographic territory. Instead, it sits as a point location within ZIP 91776, the standard San Gabriel delivery zone. Residents and businesses in San Gabriel have a choice: receive mail at their street address through 91776 or rent one of 726 PO Boxes and use 91778.
The post office at 120 S Del Mar Avenue handles all 91778 mail. Every ZIP+4 record for this code traces back to that single address. The 289 business delivery points suggest local shops, professionals, and organizations prefer the privacy or reliability of a PO Box over storefront delivery. With 5 registered business establishments employing 8 people at this ZIP, some small operations use their box as a primary business address.
San Gabriel sits in the heart of the San Gabriel Valley, surrounded by Alhambra, San Marino, Rosemead, and Temple City. This dense suburban area east of Los Angeles gives residents plenty of postal options. Choosing a PO Box here isn't about necessity. Street delivery works fine through 91776. It's about preference: a permanent address that won't change when you move, package security, or business professionalism.
The only street address is the post office location itself at 120 S Del Mar Avenue.
ZIP Code 91778 supports both business and residential activity. According to the Business Census (2024), there are 5 business establishments, employing about 6 people with an annual payroll of $230,000.
| # Residential Mailboxes: | 0Source: USPS |
| # Business Mailboxes: | 0Source: USPS |
| Total Delivery Receptacles: | 2,486Source: USPS |
| Single Family Delivery Units: | 0Source: USPS |
| Multi Family Delivery Units: | 0Source: USPS |
| # of Businesses: | 5Source: CBP |
| 1st Quarter Payroll: | $32,000Source: CBP |
| Annual Payroll: | $230,000Source: CBP |
| # of Employees: | 6Source: CBP |
ZIP Code 91778 is located in Los Angeles County, California, within the Los Angeles-Long Beach-Anaheim, CA Metropolitan Statistical Area (CBSA 31080) and California's 28th Congressional District. This Metro area has a population of 13,012,469 people, about 0.00% of whom live in ZIP Code 91778, and is subdivided into the Los Angeles-Long Beach-Glendale, CA division. It covers 0 sq mi of land and a water area of 0 sq mi.
| CBSA Name: | Los Angeles-Long Beach-Anaheim, CASource: Census |
| CBSA Number: | 31080Source: Census |
| CBSA Type: | MetroSource: Census |
| CBSA Division: | Los Angeles-Long Beach-Glendale, CA (CBSA Div 31084)Source: Census |
| CBSA Population: | 13,012,469Source: Census |
| MSA: | Los Angeles-Riverside-Orange County, CASource: Census |
| Land Area: | --Source: Census |
| Water Area: | --Source: Census |
| Congressional District: | 28Source: USPS |
| Congressional Land Area: | 218.45 sq miSource: Census |
| PMSA: | Los Angeles-Long Beach, CA PMSASource: Census |
| Intro Date: | < 2004-10Source: ZIP-Codes.com |
| Place FIPS Code: | 0667042Source: Census |
| Place Name: | San Gabriel city; CaliforniaSource: Census |
We could not locate which school district 91778 belongs to, but we will update this once new district data is released. There are no public schools nor private schools with a mailing address in this ZIP Code. Listing Nearby schools instead. It also has 6 colleges, universities or post secondary education institutions nearby which would be a short commute to.
Our sources include trusted federal and licensed data from the United States Postal Service, U.S. Census Bureau, U.S. Geological Survey, Centers for Medicare & Medicaid Services, and the National Center for Education Statistics, along with proprietary datasets created by ZIP-Codes.com. Data last updated on January 1, 2026.