ZIP Code 45342 — Miamisburg, OH
45342 is a standard (street delivery) ZIP code serving Miamisburg, Ohio, in Montgomery 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 45342 at a glance
| ZIP code | 45342 |
|---|---|
| Primary city | Miamisburg |
| State | Ohio (OH) |
| County | Montgomery FIPS 39113 |
| ZIP type | Standard (street delivery) |
| Time zone | America/New_York |
| Population | 36,152 |
| Coordinates | 39.629430, -84.275450 |
How ZIP+4 works in 45342
The four digits after the hyphen encode a delivery segment inside 45342. 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 45342 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 45342.
| ZIP | City | Distance |
|---|---|---|
| 45449 | Dayton, OH | 3.1 mi |
| 45439 | Dayton, OH | 5.4 mi |
| 45459 | Dayton, OH | 5.9 mi |
| 45066 | Springboro, OH | 6.2 mi |
| 45327 | Germantown, OH | 6.5 mi |
| 45458 | Dayton, OH | 6.6 mi |
| 45005 | Franklin, OH | 6.7 mi |
| 45429 | Dayton, OH | 7.1 mi |
| 45417 | Dayton, OH | 7.2 mi |
| 45428 | Dayton, OH | 7.8 mi |
| 45409 | Dayton, OH | 7.9 mi |
| 45419 | Dayton, OH | 8.2 mi |
Questions about 45342
What is the ZIP+4 code for 45342?
45342 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 45342, you need to look up a specific street address to get them.
What city is 45342?
45342 is assigned to Miamisburg, Ohio, in Montgomery 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.