ZIP Code 15478 — Smithfield, PA
15478 is a standard (street delivery) ZIP code serving Smithfield, Pennsylvania, in Fayette 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 15478 at a glance
| ZIP code | 15478 |
|---|---|
| Primary city | Smithfield |
| State | Pennsylvania (PA) |
| County | Fayette FIPS 42051 |
| ZIP type | Standard (street delivery) |
| Time zone | America/New_York |
| Population | 5,560 |
| Coordinates | 39.786010, -79.800990 |
How ZIP+4 works in 15478
The four digits after the hyphen encode a delivery segment inside 15478. 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 15478 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 15478.
| ZIP | City | Distance |
|---|---|---|
| 15451 | Lake Lynn, PA | 3.8 mi |
| 15436 | Fairchance, PA | 4.6 mi |
| 15467 | New Geneva, PA | 5.5 mi |
| 15474 | Point Marion, PA | 5.8 mi |
| 15460 | Martin, PA | 5.8 mi |
| 15461 | Masontown, PA | 6.4 mi |
| 15416 | Brownfield, PA | 6.5 mi |
| 15454 | Leckrone, PA | 6.6 mi |
| 15484 | Uledi, PA | 7.4 mi |
| 15458 | Mcclellandtown, PA | 7.5 mi |
| 15401 | Uniontown, PA | 8.3 mi |
| 15476 | Ronco, PA | 8.6 mi |
Questions about 15478
What is the ZIP+4 code for 15478?
15478 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 15478, you need to look up a specific street address to get them.
What city is 15478?
15478 is assigned to Smithfield, Pennsylvania, in Fayette 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.