ZIP Code 78009 — Castroville, TX
78009 is a standard (street delivery) ZIP code serving Castroville, Texas, in Medina 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 78009 at a glance
| ZIP code | 78009 |
|---|---|
| Primary city | Castroville |
| State | Texas (TX) |
| County | Medina FIPS 48325 |
| ZIP type | Standard (street delivery) |
| Time zone | America/Chicago |
| Population | 9,151 |
| Coordinates | 29.362510, -98.884420 |
How ZIP+4 works in 78009
The four digits after the hyphen encode a delivery segment inside 78009. 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 78009 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 78009.
| ZIP | City | Distance |
|---|---|---|
| 78039 | La Coste, TX | 4.9 mi |
| 78066 | Rio Medina, TX | 8.8 mi |
| 78245 | San Antonio, TX | 9.3 mi |
| 78253 | San Antonio, TX | 9.3 mi |
| 78002 | Atascosa, TX | 10.4 mi |
| 78252 | San Antonio, TX | 11.4 mi |
| 78059 | Natalia, TX | 12 mi |
| 78056 | Mico, TX | 12.7 mi |
| 78052 | Lytle, TX | 12.7 mi |
| 78016 | Devine, TX | 13 mi |
| 78251 | San Antonio, TX | 14.2 mi |
| 78227 | San Antonio, TX | 14.9 mi |
Questions about 78009
What is the ZIP+4 code for 78009?
78009 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 78009, you need to look up a specific street address to get them.
What city is 78009?
78009 is assigned to Castroville, Texas, in Medina 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.