ZIP Code 21540 — Luke, MD
21540 is a standard (street delivery) ZIP code serving Luke, Maryland, in Allegany 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 21540 at a glance
| ZIP code | 21540 |
|---|---|
| Primary city | Luke |
| State | Maryland (MD) |
| County | Allegany FIPS 24001 |
| ZIP type | Standard (street delivery) |
| Time zone | America/New_York |
| Population | 89 |
| Coordinates | 39.476590, -79.059290 |
How ZIP+4 works in 21540
The four digits after the hyphen encode a delivery segment inside 21540. 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 21540 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 21540.
| ZIP | City | Distance |
|---|---|---|
| 26750 | Piedmont, WV | 0.7 mi |
| 21523 | Bloomington, MD | 1.1 mi |
| 21562 | Westernport, MD | 1.9 mi |
| 21521 | Barton, MD | 5.1 mi |
| 26726 | Keyser, WV | 6.4 mi |
| 21557 | Rawlings, MD | 7.8 mi |
| 21561 | Swanton, MD | 7.9 mi |
| 21539 | Lonaconing, MD | 8.8 mi |
| 21542 | Midland, MD | 9.8 mi |
| 21538 | Kitzmiller, MD | 10.1 mi |
| 26717 | Elk Garden, WV | 11 mi |
| 21543 | Midlothian, MD | 12.5 mi |
Questions about 21540
What is the ZIP+4 code for 21540?
21540 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 21540, you need to look up a specific street address to get them.
What city is 21540?
21540 is assigned to Luke, Maryland, in Allegany 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.