ZIP Code 61437 — Gladstone, IL
61437 is a standard (street delivery) ZIP code serving Gladstone, Illinois, in Henderson 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 61437 at a glance
| ZIP code | 61437 |
|---|---|
| Primary city | Gladstone |
| State | Illinois (IL) |
| County | Henderson FIPS 17071 |
| ZIP type | Standard (street delivery) |
| Time zone | America/Chicago |
| Population | 549 |
| Coordinates | 40.849110, -90.989050 |
How ZIP+4 works in 61437
The four digits after the hyphen encode a delivery segment inside 61437. 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 61437 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 61437.
| ZIP | City | Distance |
|---|---|---|
| 52601 | Burlington, IA | 6.4 mi |
| 61418 | Biggsville, IL | 6.5 mi |
| 61425 | Carman, IL | 6.6 mi |
| 61469 | Oquawka, IL | 8.8 mi |
| 61480 | Stronghurst, IL | 9.4 mi |
| 52650 | Sperry, IA | 11.1 mi |
| 52655 | West Burlington, IA | 11.6 mi |
| 61447 | Kirkwood, IL | 11.7 mi |
| 61454 | Lomax, IL | 11.9 mi |
| 61460 | Media, IL | 12.2 mi |
| 61478 | Smithshire, IL | 13.5 mi |
| 61471 | Raritan, IL | 13.6 mi |
Questions about 61437
What is the ZIP+4 code for 61437?
61437 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 61437, you need to look up a specific street address to get them.
What city is 61437?
61437 is assigned to Gladstone, Illinois, in Henderson 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.