ZIP Code 48603 — Saginaw, MI
48603 is a standard (street delivery) ZIP code serving Saginaw, Michigan, in Saginaw 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 48603 at a glance
| ZIP code | 48603 |
|---|---|
| Primary city | Saginaw |
| State | Michigan (MI) |
| County | Saginaw FIPS 26145 |
| ZIP type | Standard (street delivery) |
| Time zone | America/Detroit |
| Population | 27,757 |
| Coordinates | 43.463320, -84.031150 |
How ZIP+4 works in 48603
The four digits after the hyphen encode a delivery segment inside 48603. 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 48603 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.
Other ZIP codes in Saginaw
Nearby ZIP codes
Showing the closest twelve. See every ZIP code within 25 miles of 48603.
| ZIP | City | Distance |
|---|---|---|
| 48638 | Saginaw, MI | 3.3 mi |
| 48602 | Saginaw, MI | 4.1 mi |
| 48604 | Saginaw, MI | 4.3 mi |
| 48724 | Carrollton, MI | 5.2 mi |
| 48607 | Saginaw, MI | 5.3 mi |
| 48609 | Saginaw, MI | 5.9 mi |
| 48623 | Freeland, MI | 6.5 mi |
| 48710 | University Center, MI | 6.8 mi |
| 48601 | Saginaw, MI | 8.1 mi |
| 48706 | Bay City, MI | 10.1 mi |
| 48626 | Hemlock, MI | 10.2 mi |
| 48708 | Bay City, MI | 11.2 mi |
Questions about 48603
What is the ZIP+4 code for 48603?
48603 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 48603, you need to look up a specific street address to get them.
What city is 48603?
48603 is assigned to Saginaw, Michigan, in Saginaw 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.