ZIP Code 51561 — Pacific Junction, IA
51561 is a standard (street delivery) ZIP code serving Pacific Junction, Iowa, in Mills 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 51561 at a glance
| ZIP code | 51561 |
|---|---|
| Primary city | Pacific Junction |
| State | Iowa (IA) |
| County | Mills FIPS 19129 |
| ZIP type | Standard (street delivery) |
| Time zone | America/Chicago |
| Population | 1,039 |
| Coordinates | 41.005710, -95.809920 |
How ZIP+4 works in 51561
The four digits after the hyphen encode a delivery segment inside 51561. 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 51561 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 51561.
| ZIP | City | Distance |
|---|---|---|
| 51534 | Glenwood, IA | 5.3 mi |
| 68048 | Plattsmouth, NE | 6.7 mi |
| 68113 | Offutt Afb, NE | 9.3 mi |
| 68123 | Bellevue, NE | 9.7 mi |
| 68409 | Murray, NE | 9.9 mi |
| 68005 | Bellevue, NE | 10.3 mi |
| 68056 | St Columbans, NE | 10.6 mi |
| 51653 | Tabor, IA | 11 mi |
| 51551 | Malvern, IA | 11.5 mi |
| 51554 | Mineola, IA | 11.7 mi |
| 51654 | Thurman, IA | 12.3 mi |
| 68133 | Papillion, NE | 12.7 mi |
Questions about 51561
What is the ZIP+4 code for 51561?
51561 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 51561, you need to look up a specific street address to get them.
What city is 51561?
51561 is assigned to Pacific Junction, Iowa, in Mills 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.