ZIP Code 51576 — Underwood, IA
51576 is a standard (street delivery) ZIP code serving Underwood, Iowa, in Pottawattamie 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 51576 at a glance
| ZIP code | 51576 |
|---|---|
| Primary city | Underwood |
| State | Iowa (IA) |
| County | Pottawattamie FIPS 19155 |
| ZIP type | Standard (street delivery) |
| Time zone | America/Chicago |
| Population | 1,769 |
| Coordinates | 41.377700, -95.709450 |
How ZIP+4 works in 51576
The four digits after the hyphen encode a delivery segment inside 51576. 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 51576 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 51576.
| ZIP | City | Distance |
|---|---|---|
| 51548 | Mcclelland, IA | 5.7 mi |
| 51559 | Neola, IA | 6.2 mi |
| 51542 | Honey Creek, IA | 7.8 mi |
| 51526 | Crescent, IA | 8.7 mi |
| 51553 | Minden, IA | 8.8 mi |
| 51503 | Council Bluffs, IA | 10.8 mi |
| 51575 | Treynor, IA | 10.9 mi |
| 68110 | Omaha, NE | 11.8 mi |
| 51510 | Carter Lake, IA | 12.4 mi |
| 68112 | Omaha, NE | 12.9 mi |
| 51501 | Council Bluffs, IA | 13.5 mi |
| 68102 | Omaha, NE | 14 mi |
Questions about 51576
What is the ZIP+4 code for 51576?
51576 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 51576, you need to look up a specific street address to get them.
What city is 51576?
51576 is assigned to Underwood, Iowa, in Pottawattamie 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.