ZIP Code 78582 — Rio Grande City, TX
78582 is a standard (street delivery) ZIP code serving Rio Grande City, Texas, in Starr 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 78582 at a glance
| ZIP code | 78582 |
|---|---|
| Primary city | Rio Grande City |
| State | Texas (TX) |
| County | Starr FIPS 48427 |
| ZIP type | Standard (street delivery) |
| Time zone | America/Chicago |
| Population | 44,741 |
| Coordinates | 26.539370, -98.739850 |
How ZIP+4 works in 78582
The four digits after the hyphen encode a delivery segment inside 78582. 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 78582 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 78582.
| ZIP | City | Distance |
|---|---|---|
| 78591 | Santa Elena, TX | 14.9 mi |
| 78584 | Roma, TX | 15.2 mi |
| 78547 | Garciasville, TX | 16.1 mi |
| 78548 | Grulla, TX | 18.9 mi |
| 78536 | Delmita, TX | 19.6 mi |
| 78595 | Sullivan City, TX | 19.8 mi |
| 78585 | Salineno, TX | 21.2 mi |
| 78576 | Penitas, TX | 22.3 mi |
| 78360 | Guerra, TX | 22.9 mi |
| 78565 | Los Ebanos, TX | 23.1 mi |
| 78560 | La Joya, TX | 24.7 mi |
| 78545 | Falcon Heights, TX | 24.9 mi |
Questions about 78582
What is the ZIP+4 code for 78582?
78582 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 78582, you need to look up a specific street address to get them.
What city is 78582?
78582 is assigned to Rio Grande City, Texas, in Starr 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.