ZIP Code 85128 — Coolidge, AZ
85128 is a standard (street delivery) ZIP code serving Coolidge, Arizona, in Pinal 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 85128 at a glance
| ZIP code | 85128 |
|---|---|
| Primary city | Coolidge |
| State | Arizona (AZ) |
| County | Pinal FIPS 04021 |
| ZIP type | Standard (street delivery) |
| Time zone | America/Phoenix |
| Population | 19,487 |
| Coordinates | 32.964680, -111.510280 |
How ZIP+4 works in 85128
The four digits after the hyphen encode a delivery segment inside 85128. 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 85128 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 85128.
| ZIP | City | Distance |
|---|---|---|
| 85191 | Valley Farms, AZ | 3.9 mi |
| 85194 | Casa Grande, AZ | 8.1 mi |
| 85143 | San Tan Valley, AZ | 13.2 mi |
| 85122 | Casa Grande, AZ | 14.2 mi |
| 85147 | Sacaton, AZ | 15.1 mi |
| 85142 | Queen Creek, AZ | 18.2 mi |
| 85132 | Florence, AZ | 18.7 mi |
| 85140 | San Tan Valley, AZ | 19.6 mi |
| 85123 | Arizona City, AZ | 20.2 mi |
| 85131 | Eloy, AZ | 21.7 mi |
| 85193 | Casa Grande, AZ | 21.7 mi |
| 85141 | Picacho, AZ | 22.4 mi |
Questions about 85128
What is the ZIP+4 code for 85128?
85128 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 85128, you need to look up a specific street address to get them.
What city is 85128?
85128 is assigned to Coolidge, Arizona, in Pinal 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.