ZIP Code 91773 — San Dimas, CA
91773 is a standard (street delivery) ZIP code serving San Dimas, 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 91773 at a glance
| ZIP code | 91773 |
|---|---|
| Primary city | San Dimas |
| State | California (CA) |
| County | Los Angeles FIPS 06037 |
| ZIP type | Standard (street delivery) |
| Time zone | America/Los_Angeles |
| Population | 33,598 |
| Coordinates | 34.107200, -117.809280 |
How ZIP+4 works in 91773
The four digits after the hyphen encode a delivery segment inside 91773. 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 91773 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 91773.
| ZIP | City | Distance |
|---|---|---|
| 91740 | Glendora, CA | 2.6 mi |
| 91724 | Covina, CA | 3.2 mi |
| 91768 | Pomona, CA | 3.2 mi |
| 91750 | La Verne, CA | 3.8 mi |
| 91741 | Glendora, CA | 4.2 mi |
| 91767 | Pomona, CA | 4.4 mi |
| 91723 | Covina, CA | 4.7 mi |
| 91766 | Pomona, CA | 5.4 mi |
| 91711 | Claremont, CA | 5.6 mi |
| 91722 | Covina, CA | 5.6 mi |
| 91791 | West Covina, CA | 5.8 mi |
| 91789 | Walnut, CA | 6.6 mi |
Questions about 91773
What is the ZIP+4 code for 91773?
91773 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 91773, you need to look up a specific street address to get them.
What city is 91773?
91773 is assigned to San Dimas, 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.