ZIP Code 42539 — Liberty, KY
42539 is a standard (street delivery) ZIP code serving Liberty, Kentucky, in Casey 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 42539 at a glance
| ZIP code | 42539 |
|---|---|
| Primary city | Liberty |
| State | Kentucky (KY) |
| County | Casey FIPS 21045 |
| ZIP type | Standard (street delivery) |
| Time zone | America/New_York |
| Population | 9,249 |
| Coordinates | 37.305660, -84.952650 |
How ZIP+4 works in 42539
The four digits after the hyphen encode a delivery segment inside 42539. 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 42539 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 42539.
| ZIP | City | Distance |
|---|---|---|
| 42528 | Dunnville, KY | 9.2 mi |
| 42541 | Middleburg, KY | 9.2 mi |
| 42566 | Yosemite, KY | 9.6 mi |
| 40437 | Hustonville, KY | 11 mi |
| 42565 | Windsor, KY | 11.1 mi |
| 42516 | Bethelridge, KY | 11.1 mi |
| 42733 | Elk Horn, KY | 12.7 mi |
| 40442 | Kings Mountain, KY | 12.7 mi |
| 42753 | Knifley, KY | 13.4 mi |
| 40009 | Bradfordsville, KY | 13.9 mi |
| 42758 | Mannsville, KY | 14.3 mi |
| 40448 | Mckinney, KY | 14.9 mi |
Questions about 42539
What is the ZIP+4 code for 42539?
42539 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 42539, you need to look up a specific street address to get them.
What city is 42539?
42539 is assigned to Liberty, Kentucky, in Casey 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.