ZIP Code 50579 — Rockwell City, IA
50579 is a standard (street delivery) ZIP code serving Rockwell City, Iowa, in Calhoun 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 50579 at a glance
| ZIP code | 50579 |
|---|---|
| Primary city | Rockwell City |
| State | Iowa (IA) |
| County | Calhoun FIPS 19025 |
| ZIP type | Standard (street delivery) |
| Time zone | America/Chicago |
| Population | 3,034 |
| Coordinates | 42.393560, -94.634500 |
How ZIP+4 works in 50579
The four digits after the hyphen encode a delivery segment inside 50579. 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 50579 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 50579.
| ZIP | City | Distance |
|---|---|---|
| 50551 | Jolley, IA | 8.7 mi |
| 51453 | Lohrville, IA | 9.9 mi |
| 50552 | Knierim, IA | 9.9 mi |
| 51449 | Lake City, IA | 10.2 mi |
| 50586 | Somers, IA | 10.3 mi |
| 50563 | Manson, IA | 10.8 mi |
| 50561 | Lytton, IA | 11 mi |
| 50575 | Pomeroy, IA | 11.9 mi |
| 50538 | Farnhamville, IA | 12.9 mi |
| 51433 | Auburn, IA | 14.5 mi |
| 51451 | Lanesboro, IA | 14.7 mi |
| 50518 | Barnum, IA | 15.2 mi |
Questions about 50579
What is the ZIP+4 code for 50579?
50579 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 50579, you need to look up a specific street address to get them.
What city is 50579?
50579 is assigned to Rockwell City, Iowa, in Calhoun 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.