ZIP Code 48458 — Mount Morris, MI
48458 is a standard (street delivery) ZIP code serving Mount Morris, Michigan, in Genesee 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 48458 at a glance
| ZIP code | 48458 |
|---|---|
| Primary city | Mount Morris |
| State | Michigan (MI) |
| County | Genesee FIPS 26049 |
| ZIP type | Standard (street delivery) |
| Time zone | America/Detroit |
| Population | 19,519 |
| Coordinates | 43.120900, -83.683080 |
How ZIP+4 works in 48458
The four digits after the hyphen encode a delivery segment inside 48458. 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 48458 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 48458.
| ZIP | City | Distance |
|---|---|---|
| 48437 | Genesee, MI | 3.3 mi |
| 48505 | Flint, MI | 3.6 mi |
| 48420 | Clio, MI | 4.3 mi |
| 48506 | Flint, MI | 4.8 mi |
| 48504 | Flint, MI | 5.6 mi |
| 48502 | Flint, MI | 7.4 mi |
| 48509 | Burton, MI | 7.6 mi |
| 48503 | Flint, MI | 7.6 mi |
| 48463 | Otisville, MI | 8.6 mi |
| 48532 | Flint, MI | 9.4 mi |
| 48433 | Flushing, MI | 9.7 mi |
| 48519 | Burton, MI | 10 mi |
Questions about 48458
What is the ZIP+4 code for 48458?
48458 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 48458, you need to look up a specific street address to get them.
What city is 48458?
48458 is assigned to Mount Morris, Michigan, in Genesee 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.