ZIP Code 20659 — Mechanicsville, MD
20659 is a standard (street delivery) ZIP code serving Mechanicsville, Maryland, in St. Mary'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 20659 at a glance
| ZIP code | 20659 |
|---|---|
| Primary city | Mechanicsville |
| State | Maryland (MD) |
| County | St. Mary's FIPS 24037 |
| ZIP type | Standard (street delivery) |
| Time zone | America/New_York |
| Population | 24,324 |
| Coordinates | 38.418860, -76.732380 |
How ZIP+4 works in 20659
The four digits after the hyphen encode a delivery segment inside 20659. 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 20659 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 20659.
| ZIP | City | Distance |
|---|---|---|
| 20660 | Morganza, MD | 3.7 mi |
| 20624 | Clements, MD | 5.8 mi |
| 20656 | Loveville, MD | 6.2 mi |
| 20622 | Charlotte Hall, MD | 6.5 mi |
| 20612 | Benedict, MD | 6.8 mi |
| 20621 | Chaptico, MD | 7 mi |
| 20637 | Hughesville, MD | 7.8 mi |
| 20636 | Hollywood, MD | 9.7 mi |
| 20618 | Bushwood, MD | 10 mi |
| 20615 | Broomes Island, MD | 10 mi |
| 20678 | Prince Frederick, MD | 10 mi |
| 20609 | Avenue, MD | 10.2 mi |
Questions about 20659
What is the ZIP+4 code for 20659?
20659 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 20659, you need to look up a specific street address to get them.
What city is 20659?
20659 is assigned to Mechanicsville, Maryland, in St. Mary'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.