Every ZIP code in Cass County

500xx–515xx

The complete list of Cass County, IA ZIP codes with the city each one delivers to.
ZIP code	City
50020	Anita
50022	Atlantic
50274	Wiota
50843	Cumberland
50853	Massena
51535	Griswold
51544	Lewis
51552	Marne

We do not publish a delivery type (standard, PO box, unique) or a neighbourhood for each ZIP.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 Cass County codes above are listed without a column we would have to invent.

Cities and towns in Cass County

Area codes covering Cass County

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

Where Cass County's ZIP codes sit

Each point is the reference point of one Cass 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 Cass 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.