ZIP Code 21638 — Grasonville, MD
21638 is a standard (street delivery) ZIP code serving Grasonville, Maryland, in Queen Anne's 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 21638 at a glance
| ZIP code | 21638 |
|---|---|
| Primary city | Grasonville |
| State | Maryland (MD) |
| County | Queen Anne's FIPS 24035 |
| ZIP type | Standard (street delivery) |
| Time zone | America/New_York |
| Population | 5,420 |
| Coordinates | 38.945130, -76.202630 |
How ZIP+4 works in 21638
The four digits after the hyphen encode a delivery segment inside 21638. 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 21638 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 21638.
| ZIP | City | Distance |
|---|---|---|
| 21658 | Queenstown, MD | 3.5 mi |
| 21619 | Chester, MD | 4.2 mi |
| 21679 | Wye Mills, MD | 6.4 mi |
| 21666 | Stevensville, MD | 7 mi |
| 21624 | Claiborne, MD | 8.5 mi |
| 21647 | Mcdaniel, MD | 10.8 mi |
| 21663 | Saint Michaels, MD | 11.3 mi |
| 21617 | Centreville, MD | 11.4 mi |
| 21657 | Queen Anne, MD | 11.4 mi |
| 21601 | Easton, MD | 12.3 mi |
| 21676 | Wittman, MD | 12.3 mi |
| 21625 | Cordova, MD | 12.4 mi |
Questions about 21638
What is the ZIP+4 code for 21638?
21638 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 21638, you need to look up a specific street address to get them.
What city is 21638?
21638 is assigned to Grasonville, Maryland, in Queen Anne's 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.