ZIP Code 21220 — Middle River, MD
21220 is a standard (street delivery) ZIP code serving Middle River, Maryland, in Baltimore 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 21220 at a glance
| ZIP code | 21220 |
|---|---|
| Primary city | Middle River |
| State | Maryland (MD) |
| County | Baltimore FIPS 24005 |
| ZIP type | Standard (street delivery) |
| Time zone | America/New_York |
| Population | 42,824 |
| Coordinates | 39.345000, -76.396600 |
How ZIP+4 works in 21220
The four digits after the hyphen encode a delivery segment inside 21220. 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 21220 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 21220.
| ZIP | City | Distance |
|---|---|---|
| 21162 | White Marsh, MD | 3.2 mi |
| 21221 | Essex, MD | 4.2 mi |
| 21128 | Perry Hall, MD | 4.9 mi |
| 21237 | Rosedale, MD | 5.2 mi |
| 21236 | Nottingham, MD | 5.6 mi |
| 21010 | Gunpowder, MD | 6.1 mi |
| 21156 | Upper Falls, MD | 6.4 mi |
| 21087 | Kingsville, MD | 7.1 mi |
| 21085 | Joppa, MD | 7.2 mi |
| 21206 | Baltimore, MD | 7.5 mi |
| 21222 | Dundalk, MD | 7.7 mi |
| 21234 | Parkville, MD | 8 mi |
Questions about 21220
What is the ZIP+4 code for 21220?
21220 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 21220, you need to look up a specific street address to get them.
What city is 21220?
21220 is assigned to Middle River, Maryland, in Baltimore 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.