ZIP Code 16159 — West Middlesex, PA
16159 is a standard (street delivery) ZIP code serving West Middlesex, Pennsylvania, in Mercer 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 16159 at a glance
| ZIP code | 16159 |
|---|---|
| Primary city | West Middlesex |
| State | Pennsylvania (PA) |
| County | Mercer FIPS 42085 |
| ZIP type | Standard (street delivery) |
| Time zone | America/New_York |
| Population | 4,455 |
| Coordinates | 41.159670, -80.468580 |
How ZIP+4 works in 16159
The four digits after the hyphen encode a delivery segment inside 16159. 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 16159 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 16159.
| ZIP | City | Distance |
|---|---|---|
| 16161 | Wheatland, PA | 3.2 mi |
| 16143 | Pulaski, PA | 3.8 mi |
| 16121 | Farrell, PA | 3.8 mi |
| 16140 | New Bedford, PA | 5.1 mi |
| 16148 | Hermitage, PA | 5.3 mi |
| 16146 | Sharon, PA | 5.4 mi |
| 44425 | Hubbard, OH | 5.5 mi |
| 16155 | Villa Maria, PA | 6.7 mi |
| 44438 | Masury, OH | 6.7 mi |
| 16142 | New Wilmington, PA | 6.8 mi |
| 16172 | New Wilmington, PA | 7.7 mi |
| 44436 | Lowellville, OH | 8 mi |
Questions about 16159
What is the ZIP+4 code for 16159?
16159 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 16159, you need to look up a specific street address to get them.
What city is 16159?
16159 is assigned to West Middlesex, Pennsylvania, in Mercer 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.