ZIP Code 99688 — Willow, AK
99688 is a standard (street delivery) ZIP code serving Willow, Alaska, in Matanuska-Susitna 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 99688 at a glance
| ZIP code | 99688 |
|---|---|
| Primary city | Willow |
| State | Alaska (AK) |
| County | Matanuska-Susitna FIPS 02170 |
| ZIP type | Standard (street delivery) |
| Time zone | America/Anchorage |
| Population | 2,739 |
| Coordinates | 61.894120, -150.047490 |
How ZIP+4 works in 99688
The four digits after the hyphen encode a delivery segment inside 99688. 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 99688 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 99688.
| ZIP | City | Distance |
|---|---|---|
| 99694 | Houston, AK | 20.3 mi |
| 99652 | Big Lake, AK | 25.5 mi |
| 99623 | Wasilla, AK | 32.4 mi |
Questions about 99688
What is the ZIP+4 code for 99688?
99688 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 99688, you need to look up a specific street address to get them.
What city is 99688?
99688 is assigned to Willow, Alaska, in Matanuska-Susitna 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.