ZIP Code 11783 — Seaford, NY
11783 is a standard (street delivery) ZIP code serving Seaford, New York, in Nassau 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 11783 at a glance
| ZIP code | 11783 |
|---|---|
| Primary city | Seaford |
| State | New York (NY) |
| County | Nassau FIPS 36059 |
| ZIP type | Standard (street delivery) |
| Time zone | America/New_York |
| Population | 21,127 |
| Coordinates | 40.677660, -73.490680 |
How ZIP+4 works in 11783
The four digits after the hyphen encode a delivery segment inside 11783. 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 11783 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 11783.
| ZIP | City | Distance |
|---|---|---|
| 11710 | Bellmore, NY | 2.2 mi |
| 11762 | Massapequa Park, NY | 2.3 mi |
| 11793 | Wantagh, NY | 2.4 mi |
| 11758 | Massapequa, NY | 2.4 mi |
| 11566 | Merrick, NY | 3.5 mi |
| 11756 | Levittown, NY | 3.6 mi |
| 11701 | Amityville, NY | 4.1 mi |
| 11714 | Bethpage, NY | 4.5 mi |
| 11554 | East Meadow, NY | 4.7 mi |
| 11735 | Farmingdale, NY | 4.8 mi |
| 11575 | Roosevelt, NY | 5 mi |
| 11726 | Copiague, NY | 5 mi |
Questions about 11783
What is the ZIP+4 code for 11783?
11783 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 11783, you need to look up a specific street address to get them.
What city is 11783?
11783 is assigned to Seaford, New York, in Nassau 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.