ZIP Code 37421 — Chattanooga, TN
37421 is a standard (street delivery) ZIP code serving Chattanooga, Tennessee, in Hamilton 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 37421 at a glance
| ZIP code | 37421 |
|---|---|
| Primary city | Chattanooga |
| State | Tennessee (TN) |
| County | Hamilton FIPS 47065 |
| ZIP type | Standard (street delivery) |
| Time zone | America/New_York |
| Population | 52,985 |
| Coordinates | 35.029150, -85.153000 |
How ZIP+4 works in 37421
The four digits after the hyphen encode a delivery segment inside 37421. 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 37421 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 Chattanooga
Nearby ZIP codes
Showing the closest twelve. See every ZIP code within 25 miles of 37421.
| ZIP | City | Distance |
|---|---|---|
| 30726 | Graysville, GA | 3.8 mi |
| 37411 | Chattanooga, TN | 4.4 mi |
| 37412 | Chattanooga, TN | 4.7 mi |
| 37416 | Chattanooga, TN | 4.8 mi |
| 37315 | Collegedale, TN | 5.9 mi |
| 37406 | Chattanooga, TN | 6 mi |
| 37404 | Chattanooga, TN | 6.8 mi |
| 37302 | Apison, TN | 7.6 mi |
| 37407 | Chattanooga, TN | 7.9 mi |
| 37351 | Lupton City, TN | 7.9 mi |
| 37363 | Ooltewah, TN | 8.1 mi |
| 37403 | Chattanooga, TN | 8.1 mi |
Questions about 37421
What is the ZIP+4 code for 37421?
37421 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 37421, you need to look up a specific street address to get them.
What city is 37421?
37421 is assigned to Chattanooga, Tennessee, in Hamilton 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.