ZIP Code 95521 — Arcata, CA
95521 is a standard (street delivery) ZIP code serving Arcata, California, in Humboldt 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 95521 at a glance
| ZIP code | 95521 |
|---|---|
| Primary city | Arcata |
| State | California (CA) |
| County | Humboldt FIPS 06023 |
| ZIP type | Standard (street delivery) |
| Time zone | America/Los_Angeles |
| Population | 21,980 |
| Coordinates | 40.845860, -124.047450 |
How ZIP+4 works in 95521
The four digits after the hyphen encode a delivery segment inside 95521. 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 95521 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 95521.
| ZIP | City | Distance |
|---|---|---|
| 95524 | Bayside, CA | 1.6 mi |
| 95501 | Eureka, CA | 5.6 mi |
| 95519 | Mckinleyville, CA | 7.8 mi |
| 95503 | Eureka, CA | 8.7 mi |
| 95564 | Samoa, CA | 9 mi |
| 95537 | Fields Landing, CA | 11.2 mi |
| 95550 | Korbel, CA | 12.3 mi |
| 95525 | Blue Lake, CA | 13.5 mi |
| 95551 | Loleta, CA | 15.1 mi |
| 95549 | Kneeland, CA | 15.2 mi |
| 95570 | Trinidad, CA | 18.6 mi |
| 95547 | Hydesville, CA | 19.1 mi |
Questions about 95521
What is the ZIP+4 code for 95521?
95521 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 95521, you need to look up a specific street address to get them.
What city is 95521?
95521 is assigned to Arcata, California, in Humboldt 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.