ZIP Code 57266 — Summit, SD
57266 is a standard (street delivery) ZIP code serving Summit, South Dakota, in Grant 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 57266 at a glance
| ZIP code | 57266 |
|---|---|
| Primary city | Summit |
| State | South Dakota (SD) |
| County | Grant FIPS 46051 |
| ZIP type | Standard (street delivery) |
| Time zone | America/Chicago |
| Population | 626 |
| Coordinates | 45.286190, -97.089850 |
How ZIP+4 works in 57266
The four digits after the hyphen encode a delivery segment inside 57266. 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 57266 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 57266.
| ZIP | City | Distance |
|---|---|---|
| 57256 | Ortley, SD | 6 mi |
| 57251 | Marvin, SD | 7.5 mi |
| 57273 | Waubay, SD | 9.6 mi |
| 57263 | South Shore, SD | 10.8 mi |
| 57279 | Wilmot, SD | 13.9 mi |
| 57269 | Twin Brooks, SD | 14.7 mi |
| 57257 | Peever, SD | 15 mi |
| 57235 | Florence, SD | 18.5 mi |
| 57227 | Corona, SD | 18.6 mi |
| 57264 | Stockholm, SD | 18.6 mi |
| 57239 | Grenville, SD | 18.9 mi |
| 57274 | Webster, SD | 22.7 mi |
Questions about 57266
What is the ZIP+4 code for 57266?
57266 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 57266, you need to look up a specific street address to get them.
What city is 57266?
57266 is assigned to Summit, South Dakota, in Grant 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.