ZIP Code 42728 — Columbia, KY
42728 is a standard (street delivery) ZIP code serving Columbia, Kentucky, in Adair 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 42728 at a glance
| ZIP code | 42728 |
|---|---|
| Primary city | Columbia |
| State | Kentucky (KY) |
| County | Adair FIPS 21001 |
| ZIP type | Standard (street delivery) |
| Time zone | America/Chicago |
| Population | 16,412 |
| Coordinates | 37.109430, -85.288730 |
How ZIP+4 works in 42728
The four digits after the hyphen encode a delivery segment inside 42728. 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 42728 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 42728.
| ZIP | City | Distance |
|---|---|---|
| 42741 | Glens Fork, KY | 8.6 mi |
| 42753 | Knifley, KY | 10.1 mi |
| 42742 | Gradyville, KY | 10.7 mi |
| 42715 | Breeding, KY | 13.3 mi |
| 42642 | Russell Springs, KY | 14.4 mi |
| 42743 | Greensburg, KY | 15.7 mi |
| 42528 | Dunnville, KY | 15.8 mi |
| 42629 | Jamestown, KY | 15.8 mi |
| 42733 | Elk Horn, KY | 17 mi |
| 42129 | Edmonton, KY | 18.5 mi |
| 42758 | Mannsville, KY | 19.1 mi |
| 42718 | Campbellsville, KY | 19.9 mi |
Questions about 42728
What is the ZIP+4 code for 42728?
42728 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 42728, you need to look up a specific street address to get them.
What city is 42728?
42728 is assigned to Columbia, Kentucky, in Adair 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.