ZIP Code 21921 — Elkton, MD
21921 is a standard (street delivery) ZIP code serving Elkton, Maryland, in Cecil 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 21921 at a glance
| ZIP code | 21921 |
|---|---|
| Primary city | Elkton |
| State | Maryland (MD) |
| County | Cecil FIPS 24015 |
| ZIP type | Standard (street delivery) |
| Time zone | America/New_York |
| Population | 45,527 |
| Coordinates | 39.625680, -75.859040 |
How ZIP+4 works in 21921
The four digits after the hyphen encode a delivery segment inside 21921. 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 21921 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 21921.
| ZIP | City | Distance |
|---|---|---|
| 21920 | Elk Mills, MD | 2.5 mi |
| 21901 | North East, MD | 5.9 mi |
| 19716 | Newark, DE | 6.7 mi |
| 19717 | Newark, DE | 6.8 mi |
| 19702 | Newark, DE | 7 mi |
| 21914 | Charlestown, MD | 7.5 mi |
| 19713 | Newark, DE | 8.5 mi |
| 21915 | Chesapeake City, MD | 8.6 mi |
| 19711 | Newark, DE | 8.8 mi |
| 19701 | Bear, DE | 9 mi |
| 19350 | Landenberg, PA | 10 mi |
| 21911 | Rising Sun, MD | 10.5 mi |
Questions about 21921
What is the ZIP+4 code for 21921?
21921 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 21921, you need to look up a specific street address to get them.
What city is 21921?
21921 is assigned to Elkton, Maryland, in Cecil 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.