ZIP Code 50401 — Mason City, IA
50401 is a standard (street delivery) ZIP code serving Mason City, Iowa, in Cerro Gordo 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 50401 at a glance
| ZIP code | 50401 |
|---|---|
| Primary city | Mason City |
| State | Iowa (IA) |
| County | Cerro Gordo FIPS 19033 |
| ZIP type | Standard (street delivery) |
| Time zone | America/Chicago |
| Population | 28,703 |
| Coordinates | 43.153890, -93.200060 |
How ZIP+4 works in 50401
The four digits after the hyphen encode a delivery segment inside 50401. 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 50401 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 50401.
| ZIP | City | Distance |
|---|---|---|
| 50467 | Rock Falls, IA | 7.7 mi |
| 50464 | Plymouth, IA | 9.2 mi |
| 50456 | Manly, IA | 9.3 mi |
| 50428 | Clear Lake, IA | 9.6 mi |
| 50458 | Nora Springs, IA | 9.8 mi |
| 50469 | Rockwell, IA | 10.7 mi |
| 50477 | Swaledale, IA | 13.2 mi |
| 50444 | Hanlontown, IA | 13.4 mi |
| 50448 | Kensett, IA | 13.8 mi |
| 50440 | Grafton, IA | 14 mi |
| 50482 | Ventura, IA | 14.3 mi |
| 50468 | Rockford, IA | 14.3 mi |
Questions about 50401
What is the ZIP+4 code for 50401?
50401 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 50401, you need to look up a specific street address to get them.
What city is 50401?
50401 is assigned to Mason City, Iowa, in Cerro Gordo 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.