Walnut Iowa ZIP Codes

Walnut holds a single ZIP code.

Every ZIP code in Walnut

The complete list of Walnut, Iowa ZIP codes with the county each falls in.
ZIP code	County
51577	Pottawattamie County

We do not publish a delivery type (standard, PO box, unique) or a neighbourhood for each ZIP.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

Scope every ZIP code recorded for Walnut. Source GeoNames US postal codes (2026-07 postal dump) and Census 2024 county Gazetteer (2024 Gazetteer). Updated 15 July 2026. ZIP codes are delivery-route groupings, not areas; the boundaries implied by any ZIP map are approximations.

How these codes cluster

Every Walnut ZIP code begins 515. Those first three digits identify the sectional center facility that processes mail for this part of Iowa. Statewide that range covers 57 ZIP codes, so Walnut accounts for 2% of it.

Every Iowa ZIP prefix and the region it covers →

Area codes covering Walnut

ZIP codes and area codes are separate systems — one routes mail, the other routes calls — and they do not share boundaries. The code below serves the same ground Walnut occupies.

712 Area code 712

Walnut Iowa area codes in full →

Where Walnut's ZIP codes sit

Each point is one Walnut ZIP code, plotted from its record coordinates.

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

Cities near Walnut

The closest places to Walnut with their own ZIP code list, nearest first.
City	Distance	ZIP codes
Avoca Iowa ZIP codes	6.1 mi	1 ZIP code
Marne Iowa ZIP codes	6.3 mi	1 ZIP code
Hancock Iowa ZIP codes	9.8 mi	1 ZIP code
Elk Horn Iowa ZIP codes	11 mi	1 ZIP code
Shelby Iowa ZIP codes	12 mi	1 ZIP code
Kimballton Iowa ZIP codes	12 mi	1 ZIP code
Atlantic Iowa ZIP codes	12 mi	1 ZIP code
Harlan Iowa ZIP codes	12 mi	2 ZIP codes

Straight-line distance between place reference points, not driving distance.