ZIP Code 91108 — San Marino, CA
91108 is a standard (street delivery) ZIP code serving San Marino, California, in Los Angeles County. To mail something here you only need these five digits — but the four-digit extension narrows delivery to a single point, and it is what USPS bulk postage discounts are priced on.
ZIP code 91108 at a glance
| ZIP code | 91108 |
|---|---|
| Primary city | San Marino |
| State | California (CA) |
| County | Los Angeles FIPS 06037 |
| ZIP type | Standard (street delivery) |
| Time zone | America/Los_Angeles |
| Population | 12,401 |
| Coordinates | 34.122320, -118.113630 |
How ZIP+4 works in 91108
The four digits after the hyphen encode a delivery segment inside 91108. In practice one segment usually means:
- One side of one block — odd numbers on a street between two cross streets
- A single large building, or one floor of it
- A group of PO boxes, sometimes a single box
- A single business that receives enough mail to warrant its own code
That is why 91108 has no single ZIP+4: two neighbors across the street from each other usually have different ones. Enter a street address above and we will return the exact nine-digit code along with the standardized USPS address format.
Nearby ZIP codes
Showing the closest twelve. See every ZIP code within 25 miles of 91108.
| ZIP | City | Distance |
|---|---|---|
| 91125 | Pasadena, CA | 1.2 mi |
| 91106 | Pasadena, CA | 1.4 mi |
| 91775 | San Gabriel, CA | 1.5 mi |
| 91101 | Pasadena, CA | 2.2 mi |
| 91801 | Alhambra, CA | 2.3 mi |
| 91776 | San Gabriel, CA | 2.5 mi |
| 91030 | South Pasadena, CA | 2.6 mi |
| 91107 | Pasadena, CA | 3 mi |
| 91104 | Pasadena, CA | 3.2 mi |
| 91105 | Pasadena, CA | 3.3 mi |
| 91780 | Temple City, CA | 3.6 mi |
| 91007 | Arcadia, CA | 3.8 mi |
Questions about 91108
What is the ZIP+4 code for 91108?
91108 is the five-digit ZIP code. The ZIP+4 adds four more digits that identify a specific delivery point — usually one side of a city block, a single building, or a group of PO boxes. Because those four digits change from address to address within 91108, you need to look up a specific street address to get them.
What city is 91108?
91108 is assigned to San Marino, California, in Los Angeles County.
Do I need to use the ZIP+4?
It is optional for ordinary mail, but it speeds up sorting and it is required for most USPS bulk-mail postage discounts. Many address-verification and e-commerce systems also use ZIP+4 to confirm a delivery point exists.
Need thousands of these?
Upload a CSV and get ZIP+4, county, carrier route, and delivery-point data appended to every row — or call the API directly.