ZIP Code 59923 — Libby, MT
59923 is a standard (street delivery) ZIP code serving Libby, Montana, in Lincoln 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 59923 at a glance
| ZIP code | 59923 |
|---|---|
| Primary city | Libby |
| State | Montana (MT) |
| County | Lincoln FIPS 30053 |
| ZIP type | Standard (street delivery) |
| Time zone | America/Denver |
| Population | 10,450 |
| Coordinates | 48.269960, -115.310730 |
How ZIP+4 works in 59923
The four digits after the hyphen encode a delivery segment inside 59923. 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 59923 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 59923.
| ZIP | City | Distance |
|---|---|---|
| 59925 | Marion, MT | 26.9 mi |
| 59853 | Noxon, MT | 27.4 mi |
| 59934 | Trego, MT | 30.3 mi |
| 59927 | Olney, MT | 33.8 mi |
| 59874 | Trout Creek, MT | 34.7 mi |
| 59935 | Troy, MT | 35.5 mi |
| 59933 | Stryker, MT | 39.2 mi |
| 59918 | Fortine, MT | 40.8 mi |
Questions about 59923
What is the ZIP+4 code for 59923?
59923 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 59923, you need to look up a specific street address to get them.
What city is 59923?
59923 is assigned to Libby, Montana, in Lincoln 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.