Grant County ZIP Codes

Grant County is a county of Washington.

ZIP codes: 16
Cities & towns: 16
Area codes: 1
Land area: 2,680 sq mi

Every ZIP code in Grant County

988xx–993xx

The complete list of Grant County, WA ZIP codes with the city each one delivers to.
ZIP code	City
98823	Ephrata
98824	George
98832	Marlin
98837	Moses Lake
98848	Quincy
98851	Soap Lake
98853	Stratford
98857	Warden
98860	Wilson Creek
99115	Coulee City
99123	Electric City
99133	Grand Coulee
99135	Hartline
99321	Beverly
99349	Mattawa
99357	Royal City

We do not publish a delivery type (standard, PO box, unique) or a neighbourhood for each ZIP. USPS delivery-type products are licensed, and no clean-rights source maps ZIP codes to neighbourhoods — so the Grant County codes above are listed without a column we would have to invent.

Cities and towns in Grant County

A further 3 places in Grant County appear in the postal source without a page of its own; their codes are in the table above and each one links to its own page.

Area codes covering Grant County

Telephone and postal boundaries are drawn by different bodies, so these codes overlap the county without matching its edges.

509 Area code 509

Where Grant County's ZIP codes sit

Each point is the reference point of one Grant County ZIP code, plotted from its record coordinates. The outline is the convex envelope of those points — a footprint, not a boundary.

Reference points and footprint
Not an official NANPA boundary
Not a USPS delivery area

Scope every ZIP code recorded in Grant County. Source GeoNames US postal codes (2026-07 postal dump), Census 2024 county Gazetteer (2024 Gazetteer) and geoinfo-dataset (full_dataset) ZIP→NPA (2018 snapshot). Updated 16 July 2026. The outline is a convex envelope of ZIP reference points, not a jurisdiction boundary.