ZIP Code 78121 — La Vernia, TX
78121 is a standard (street delivery) ZIP code serving La Vernia, Texas, in Wilson 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 78121 at a glance
| ZIP code | 78121 |
|---|---|
| Primary city | La Vernia |
| State | Texas (TX) |
| County | Wilson FIPS 48493 |
| ZIP type | Standard (street delivery) |
| Time zone | America/Chicago |
| Population | 16,120 |
| Coordinates | 29.351180, -98.102410 |
How ZIP+4 works in 78121
The four digits after the hyphen encode a delivery segment inside 78121. 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 78121 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 78121.
| ZIP | City | Distance |
|---|---|---|
| 78161 | Sutherland Springs, TX | 5.4 mi |
| 78101 | Adkins, TX | 7.9 mi |
| 78152 | Saint Hedwig, TX | 8.1 mi |
| 78263 | San Antonio, TX | 12.6 mi |
| 78160 | Stockdale, TX | 12.9 mi |
| 78109 | Converse, TX | 14.5 mi |
| 78124 | Marion, TX | 14.6 mi |
| 78143 | Pandora, TX | 15.8 mi |
| 78155 | Seguin, TX | 16 mi |
| 78154 | Schertz, TX | 16.7 mi |
| 78150 | Jbsa Randolph, TX | 16.8 mi |
| 78222 | San Antonio, TX | 16.9 mi |
Questions about 78121
What is the ZIP+4 code for 78121?
78121 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 78121, you need to look up a specific street address to get them.
What city is 78121?
78121 is assigned to La Vernia, Texas, in Wilson 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.