ZIP Codes in Oak Harbor, WA
Oak Harbor uses 2 ZIP codes, all in Island County. Pick one below for details, or look up the full nine-digit ZIP+4 for a specific street address.
All 2 Oak Harbor ZIP codes
| ZIP | Type | County | Population |
|---|---|---|---|
| 98277 | standard | Island | 40,917 |
| 98278 | standard | Island | 1,932 |
Finding a ZIP+4 in Oak Harbor
Knowing which of these 2 ZIP codes covers an address only gets you partway. The four-digit extension identifies the specific delivery point — typically one side of one block. Two houses facing each other on the same Oak Harbor street almost always have different ZIP+4 codes even though they share all five leading digits.
Appending ZIP+4 to a mailing list?
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