ZIP Code 15557 — Rockwood, PA
15557 is a standard (street delivery) ZIP code serving Rockwood, Pennsylvania, in Somerset 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 15557 at a glance
| ZIP code | 15557 |
|---|---|
| Primary city | Rockwood |
| State | Pennsylvania (PA) |
| County | Somerset FIPS 42111 |
| ZIP type | Standard (street delivery) |
| Time zone | America/New_York |
| Population | 3,323 |
| Coordinates | 39.927570, -79.209450 |
How ZIP+4 works in 15557
The four digits after the hyphen encode a delivery segment inside 15557. 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 15557 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 15557.
| ZIP | City | Distance |
|---|---|---|
| 15551 | Markleton, PA | 4.3 mi |
| 15502 | Hidden Valley, PA | 7.8 mi |
| 15542 | Garrett, PA | 8.1 mi |
| 15501 | Somerset, PA | 8.6 mi |
| 15540 | Fort Hill, PA | 9.2 mi |
| 15510 | Somerset, PA | 9.3 mi |
| 15622 | Champion, PA | 9.4 mi |
| 15424 | Confluence, PA | 10.2 mi |
| 15464 | Mill Run, PA | 12 mi |
| 15446 | Indian Head, PA | 12.1 mi |
| 15469 | Normalville, PA | 12.6 mi |
| 15565 | West Salisbury, PA | 12.6 mi |
Questions about 15557
What is the ZIP+4 code for 15557?
15557 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 15557, you need to look up a specific street address to get them.
What city is 15557?
15557 is assigned to Rockwood, Pennsylvania, in Somerset 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.