ZIP Code 99664 — Seward, AK
99664 is a standard (street delivery) ZIP code serving Seward, Alaska, in Kenai Peninsula 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 99664 at a glance
| ZIP code | 99664 |
|---|---|
| Primary city | Seward |
| State | Alaska (AK) |
| County | Kenai Peninsula FIPS 02122 |
| ZIP type | Standard (street delivery) |
| Time zone | America/Anchorage |
| Population | 4,698 |
| Coordinates | 60.137140, -149.471230 |
How ZIP+4 works in 99664
The four digits after the hyphen encode a delivery segment inside 99664. 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 99664 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 99664.
| ZIP | City | Distance |
|---|---|---|
| 99572 | Cooper Landing, AK | 31.8 mi |
| 99631 | Moose Pass, AK | 32.6 mi |
Questions about 99664
What is the ZIP+4 code for 99664?
99664 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 99664, you need to look up a specific street address to get them.
What city is 99664?
99664 is assigned to Seward, Alaska, in Kenai Peninsula 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.