ZIP Code 37138 — Old Hickory, TN
37138 is a standard (street delivery) ZIP code serving Old Hickory, Tennessee, in Davidson 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 37138 at a glance
| ZIP code | 37138 |
|---|---|
| Primary city | Old Hickory |
| State | Tennessee (TN) |
| County | Davidson FIPS 47037 |
| ZIP type | Standard (street delivery) |
| Time zone | America/Chicago |
| Population | 22,575 |
| Coordinates | 36.246520, -86.619380 |
How ZIP+4 works in 37138
The four digits after the hyphen encode a delivery segment inside 37138. 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 37138 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 37138.
| ZIP | City | Distance |
|---|---|---|
| 37115 | Madison, TN | 4.3 mi |
| 37214 | Nashville, TN | 5.9 mi |
| 37216 | Nashville, TN | 6.3 mi |
| 37075 | Hendersonville, TN | 6.5 mi |
| 37076 | Hermitage, TN | 7.3 mi |
| 37206 | Nashville, TN | 7.7 mi |
| 37122 | Mount Juliet, TN | 8.7 mi |
| 37207 | Nashville, TN | 8.9 mi |
| 37210 | Nashville, TN | 9.5 mi |
| 37217 | Nashville, TN | 9.8 mi |
| 37213 | Nashville, TN | 9.9 mi |
| 37072 | Goodlettsville, TN | 10.3 mi |
Questions about 37138
What is the ZIP+4 code for 37138?
37138 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 37138, you need to look up a specific street address to get them.
What city is 37138?
37138 is assigned to Old Hickory, Tennessee, in Davidson 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.