ZIP Code 11766 — Mount Sinai, NY
11766 is a standard (street delivery) ZIP code serving Mount Sinai, New York, in Suffolk 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 11766 at a glance
| ZIP code | 11766 |
|---|---|
| Primary city | Mount Sinai |
| State | New York (NY) |
| County | Suffolk FIPS 36103 |
| ZIP type | Standard (street delivery) |
| Time zone | America/New_York |
| Population | 10,750 |
| Coordinates | 40.936020, -73.016450 |
How ZIP+4 works in 11766
The four digits after the hyphen encode a delivery segment inside 11766. 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 11766 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 11766.
| ZIP | City | Distance |
|---|---|---|
| 11764 | Miller Place, NY | 2.1 mi |
| 11776 | Port Jefferson Station, NY | 2.2 mi |
| 11789 | Sound Beach, NY | 2.7 mi |
| 11777 | Port Jefferson, NY | 2.7 mi |
| 11727 | Coram, NY | 3.9 mi |
| 11778 | Rocky Point, NY | 4.5 mi |
| 11733 | East Setauket, NY | 4.6 mi |
| 11784 | Selden, NY | 4.8 mi |
| 11953 | Middle Island, NY | 4.9 mi |
| 11720 | Centereach, NY | 5.7 mi |
| 11794 | Stony Brook, NY | 5.8 mi |
| 11790 | Stony Brook, NY | 6.1 mi |
Questions about 11766
What is the ZIP+4 code for 11766?
11766 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 11766, you need to look up a specific street address to get them.
What city is 11766?
11766 is assigned to Mount Sinai, New York, in Suffolk 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.