ZIP Code 94963 — San Geronimo, CA
94963 is a standard (street delivery) ZIP code serving San Geronimo, California, in Marin 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 94963 at a glance
| ZIP code | 94963 |
|---|---|
| Primary city | San Geronimo |
| State | California (CA) |
| County | Marin FIPS 06041 |
| ZIP type | Standard (street delivery) |
| Time zone | America/Los_Angeles |
| Population | 739 |
| Coordinates | 38.007650, -122.664840 |
How ZIP+4 works in 94963
The four digits after the hyphen encode a delivery segment inside 94963. 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 94963 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 94963.
| ZIP | City | Distance |
|---|---|---|
| 94933 | Forest Knolls, CA | 1.4 mi |
| 94973 | Woodacre, CA | 1.4 mi |
| 94938 | Lagunitas, CA | 3.8 mi |
| 94930 | Fairfax, CA | 3.9 mi |
| 94946 | Nicasio, CA | 4.6 mi |
| 94960 | San Anselmo, CA | 4.8 mi |
| 94924 | Bolinas, CA | 5.2 mi |
| 94950 | Olema, CA | 5.4 mi |
| 94903 | San Rafael, CA | 6.2 mi |
| 94970 | Stinson Beach, CA | 6.3 mi |
| 94957 | Ross, CA | 6.4 mi |
| 94941 | Mill Valley, CA | 6.6 mi |
Questions about 94963
What is the ZIP+4 code for 94963?
94963 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 94963, you need to look up a specific street address to get them.
What city is 94963?
94963 is assigned to San Geronimo, California, in Marin 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.