ZIP Code 99170 — Rosalia, WA
99170 is a standard (street delivery) ZIP code serving Rosalia, Washington, in Whitman 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 99170 at a glance
| ZIP code | 99170 |
|---|---|
| Primary city | Rosalia |
| State | Washington (WA) |
| County | Whitman FIPS 53075 |
| ZIP type | Standard (street delivery) |
| Time zone | America/Los_Angeles |
| Population | 926 |
| Coordinates | 47.251320, -117.402030 |
How ZIP+4 works in 99170
The four digits after the hyphen encode a delivery segment inside 99170. 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 99170 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 99170.
| ZIP | City | Distance |
|---|---|---|
| 99149 | Malden, WA | 3.6 mi |
| 99039 | Waverly, WA | 10 mi |
| 99176 | Thornton, WA | 11 mi |
| 99158 | Oakesdale, WA | 11.1 mi |
| 99031 | Spangle, WA | 11.8 mi |
| 99018 | Latah, WA | 12 mi |
| 99012 | Fairfield, WA | 13.3 mi |
| 99033 | Tekoa, WA | 14.3 mi |
| 99004 | Cheney, WA | 15.4 mi |
| 99171 | Saint John, WA | 15.4 mi |
| 99174 | Steptoe, WA | 17 mi |
| 99128 | Farmington, WA | 18.1 mi |
Questions about 99170
What is the ZIP+4 code for 99170?
99170 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 99170, you need to look up a specific street address to get them.
What city is 99170?
99170 is assigned to Rosalia, Washington, in Whitman 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.