ZIP Code 83428 — Irwin, ID
83428 is a standard (street delivery) ZIP code serving Irwin, Idaho, in Bonneville 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 83428 at a glance
| ZIP code | 83428 |
|---|---|
| Primary city | Irwin |
| State | Idaho (ID) |
| County | Bonneville FIPS 16019 |
| ZIP type | Standard (street delivery) |
| Time zone | America/Boise |
| Population | 576 |
| Coordinates | 43.383300, -111.160930 |
How ZIP+4 works in 83428
The four digits after the hyphen encode a delivery segment inside 83428. 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 83428 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 83428.
| ZIP | City | Distance |
|---|---|---|
| 83449 | Swan Valley, ID | 10.4 mi |
| 83014 | Wilson, WY | 12.3 mi |
| 83455 | Victor, ID | 15.4 mi |
| 83120 | Freedom, WY | 21.9 mi |
| 83443 | Ririe, ID | 21.9 mi |
| 83025 | Teton Village, WY | 22.1 mi |
| 83422 | Driggs, ID | 22.5 mi |
| 83285 | Wayan, ID | 24.6 mi |
| 83128 | Alpine, WY | 24.6 mi |
| 83118 | Etna, WY | 24.9 mi |
| 83001 | Jackson, WY | 27.7 mi |
| 83427 | Iona, ID | 29.6 mi |
Questions about 83428
What is the ZIP+4 code for 83428?
83428 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 83428, you need to look up a specific street address to get them.
What city is 83428?
83428 is assigned to Irwin, Idaho, in Bonneville 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.