ZIP Code 21651 — Millington, MD
21651 is a standard (street delivery) ZIP code serving Millington, Maryland, in Kent 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 21651 at a glance
| ZIP code | 21651 |
|---|---|
| Primary city | Millington |
| State | Maryland (MD) |
| County | Kent FIPS 24029 |
| ZIP type | Standard (street delivery) |
| Time zone | America/New_York |
| Population | 2,290 |
| Coordinates | 39.258210, -75.858020 |
How ZIP+4 works in 21651
The four digits after the hyphen encode a delivery segment inside 21651. 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 21651 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 21651.
| ZIP | City | Distance |
|---|---|---|
| 21628 | Crumpton, MD | 3.8 mi |
| 21650 | Massey, MD | 4.6 mi |
| 21668 | Sudlersville, MD | 4.7 mi |
| 21635 | Galena, MD | 5.7 mi |
| 21645 | Kennedyville, MD | 7 mi |
| 21930 | Georgetown, MD | 8 mi |
| 19938 | Clayton, DE | 8.5 mi |
| 21607 | Barclay, MD | 8.6 mi |
| 21649 | Marydel, MD | 9.5 mi |
| 21644 | Ingleside, MD | 9.8 mi |
| 19955 | Kenton, DE | 10.5 mi |
| 21913 | Cecilton, MD | 10.5 mi |
Questions about 21651
What is the ZIP+4 code for 21651?
21651 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 21651, you need to look up a specific street address to get them.
What city is 21651?
21651 is assigned to Millington, Maryland, in Kent 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.