ZIP Code 48028 — Harsens Island, MI
48028 is a standard (street delivery) ZIP code serving Harsens Island, Michigan, in St. Clair 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 48028 at a glance
| ZIP code | 48028 |
|---|---|
| Primary city | Harsens Island |
| State | Michigan (MI) |
| County | St. Clair FIPS 26147 |
| ZIP type | Standard (street delivery) |
| Time zone | America/Detroit |
| Population | 1,272 |
| Coordinates | 42.589470, -82.619480 |
How ZIP+4 works in 48028
The four digits after the hyphen encode a delivery segment inside 48028. 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 48028 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 48028.
| ZIP | City | Distance |
|---|---|---|
| 48001 | Algonac, MI | 3.9 mi |
| 48023 | Fair Haven, MI | 8 mi |
| 48039 | Marine City, MI | 8.2 mi |
| 48047 | New Baltimore, MI | 10.1 mi |
| 48045 | Harrison Township, MI | 10.7 mi |
| 48064 | Casco, MI | 12.6 mi |
| 48051 | New Baltimore, MI | 12.6 mi |
| 48054 | East China, MI | 13.1 mi |
| 48043 | Mount Clemens, MI | 13.4 mi |
| 48048 | New Haven, MI | 13.8 mi |
| 48036 | Clinton Township, MI | 14.2 mi |
| 48082 | Saint Clair Shores, MI | 14.3 mi |
Questions about 48028
What is the ZIP+4 code for 48028?
48028 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 48028, you need to look up a specific street address to get them.
What city is 48028?
48028 is assigned to Harsens Island, Michigan, in St. Clair 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.