ZIP Code 81138 — Jaroso, CO
81138 is a standard (street delivery) ZIP code serving Jaroso, Colorado, in Costilla 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 81138 at a glance
| ZIP code | 81138 |
|---|---|
| Primary city | Jaroso |
| State | Colorado (CO) |
| County | Costilla FIPS 08023 |
| ZIP type | Standard (street delivery) |
| Time zone | America/Denver |
| Population | 17 |
| Coordinates | 37.023020, -105.627370 |
How ZIP+4 works in 81138
The four digits after the hyphen encode a delivery segment inside 81138. 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 81138 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 81138.
| ZIP | City | Distance |
|---|---|---|
| 87524 | Costilla, NM | 6.2 mi |
| 87556 | Questa, NM | 14.6 mi |
| 81152 | San Luis, CO | 14.7 mi |
| 81151 | Sanford, CO | 15.3 mi |
| 87512 | Amalia, NM | 16.5 mi |
| 81141 | Manassa, CO | 17.6 mi |
| 87519 | Cerro, NM | 17.8 mi |
| 81126 | Chama, CO | 18.1 mi |
| 81148 | Romeo, CO | 22.2 mi |
| 81129 | Conejos, CO | 22.4 mi |
| 81123 | Blanca, CO | 26.6 mi |
| 87558 | Red River, NM | 27.1 mi |
Questions about 81138
What is the ZIP+4 code for 81138?
81138 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 81138, you need to look up a specific street address to get them.
What city is 81138?
81138 is assigned to Jaroso, Colorado, in Costilla 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.