ZIP Code 42021 — Arlington, KY
42021 is a standard (street delivery) ZIP code serving Arlington, Kentucky, in Carlisle 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 42021 at a glance
| ZIP code | 42021 |
|---|---|
| Primary city | Arlington |
| State | Kentucky (KY) |
| County | Carlisle FIPS 21039 |
| ZIP type | Standard (street delivery) |
| Time zone | America/Chicago |
| Population | 1,090 |
| Coordinates | 36.801290, -88.995700 |
How ZIP+4 works in 42021
The four digits after the hyphen encode a delivery segment inside 42021. 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 42021 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 42021.
| ZIP | City | Distance |
|---|---|---|
| 42023 | Bardwell, KY | 5.2 mi |
| 42032 | Columbus, KY | 6.9 mi |
| 42031 | Clinton, KY | 7.9 mi |
| 42039 | Fancy Farm, KY | 9.3 mi |
| 42035 | Cunningham, KY | 11.3 mi |
| 42087 | Wickliffe, KY | 11.9 mi |
| 42061 | Lowes, KY | 13.7 mi |
| 42060 | Lovelaceville, KY | 14.6 mi |
| 63882 | Wyatt, MO | 14.7 mi |
| 42069 | Melber, KY | 15.6 mi |
| 63834 | Charleston, MO | 17.7 mi |
| 63820 | Anniston, MO | 18.3 mi |
Questions about 42021
What is the ZIP+4 code for 42021?
42021 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 42021, you need to look up a specific street address to get them.
What city is 42021?
42021 is assigned to Arlington, Kentucky, in Carlisle 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.