ZIP Code 48721 — Black River, MI
48721 is a standard (street delivery) ZIP code serving Black River, Michigan, in Alcona 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 48721 at a glance
| ZIP code | 48721 |
|---|---|
| Primary city | Black River |
| State | Michigan (MI) |
| County | Alcona FIPS 26001 |
| ZIP type | Standard (street delivery) |
| Time zone | America/Detroit |
| Population | 406 |
| Coordinates | 44.804530, -83.345900 |
How ZIP+4 works in 48721
The four digits after the hyphen encode a delivery segment inside 48721. 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 48721 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 48721.
| ZIP | City | Distance |
|---|---|---|
| 48762 | Spruce, MI | 6.9 mi |
| 48742 | Lincoln, MI | 7.6 mi |
| 49766 | Ossineke, MI | 8.7 mi |
| 48740 | Harrisville, MI | 10.1 mi |
| 49747 | Hubbard Lake, MI | 15 mi |
| 48705 | Barton City, MI | 17.1 mi |
| 48745 | Mikado, MI | 17.3 mi |
| 48738 | Greenbush, MI | 17.6 mi |
| 49744 | Herron, MI | 20.8 mi |
| 49707 | Alpena, MI | 21.4 mi |
| 48728 | Curran, MI | 23.7 mi |
| 48737 | Glennie, MI | 25.2 mi |
Questions about 48721
What is the ZIP+4 code for 48721?
48721 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 48721, you need to look up a specific street address to get them.
What city is 48721?
48721 is assigned to Black River, Michigan, in Alcona 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.