ZIP Code 16623 — Cassville, PA
16623 is a standard (street delivery) ZIP code serving Cassville, Pennsylvania, in Huntingdon 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 16623 at a glance
| ZIP code | 16623 |
|---|---|
| Primary city | Cassville |
| State | Pennsylvania (PA) |
| County | Huntingdon FIPS 42061 |
| ZIP type | Standard (street delivery) |
| Time zone | America/New_York |
| Population | 492 |
| Coordinates | 40.276180, -78.045560 |
How ZIP+4 works in 16623
The four digits after the hyphen encode a delivery segment inside 16623. 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 16623 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 16623.
| ZIP | City | Distance |
|---|---|---|
| 16685 | Todd, PA | 1.9 mi |
| 16622 | Calvin, PA | 3.8 mi |
| 17052 | Mapleton Depot, PA | 4.3 mi |
| 17253 | Saltillo, PA | 4.9 mi |
| 16621 | Broad Top, PA | 5.2 mi |
| 16674 | Robertsdale, PA | 6.4 mi |
| 17264 | Three Springs, PA | 7.2 mi |
| 16657 | James Creek, PA | 7.7 mi |
| 17249 | Rockhill Furnace, PA | 8 mi |
| 17260 | Shirleysburg, PA | 8.1 mi |
| 16634 | Dudley, PA | 8.1 mi |
| 16694 | Wood, PA | 8.4 mi |
Questions about 16623
What is the ZIP+4 code for 16623?
16623 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 16623, you need to look up a specific street address to get them.
What city is 16623?
16623 is assigned to Cassville, Pennsylvania, in Huntingdon 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.