ZIP Code 83121 — Frontier, WY
83121 is a standard (street delivery) ZIP code serving Frontier, Wyoming, 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 83121 at a glance
| ZIP code | 83121 |
|---|---|
| Primary city | Frontier |
| State | Wyoming (WY) |
| County | Lincoln FIPS 56023 |
| ZIP type | Standard (street delivery) |
| Time zone | America/Denver |
| Coordinates | 41.849820, -110.540230 |
How ZIP+4 works in 83121
The four digits after the hyphen encode a delivery segment inside 83121. 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 83121 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 83121.
| ZIP | City | Distance |
|---|---|---|
| 83116 | Diamondville, WY | 6 mi |
| 83101 | Kemmerer, WY | 8.6 mi |
| 83124 | Opal, WY | 18.4 mi |
| 83114 | Cokeville, WY | 27.4 mi |
| 83123 | La Barge, WY | 30.5 mi |
| 82934 | Granger, WY | 32.4 mi |
| 84064 | Randolph, UT | 32.4 mi |
Questions about 83121
What is the ZIP+4 code for 83121?
83121 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 83121, you need to look up a specific street address to get them.
What city is 83121?
83121 is assigned to Frontier, Wyoming, 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.