Montana ZIP Codes

ZIP codes: 404
Cities & towns: 360
Counties: 56
Area codes: 1

How Montana ZIP codes are numbered

590xx–599xx

The first three digits identify the sectional center facility that processes mail for a region, so a Montana ZIP code can be placed geographically from its prefix alone. Each row names the city holding the most codes in that prefix.

Montana three-digit ZIP prefixes, the codes in each, and the city that holds the most of them.
Prefix	ZIP codes	Main area
590xx	75	Ashland
591xx	14	Billings
592xx	41	Antelope
593xx	31	Alzada
594xx	64	Great Falls
595xx	23	Big Sandy
596xx	24	Helena
597xx	49	Bozeman
598xx	53	Missoula
599xx	30	Kalispell

Where Montana's communities sit

Each point is a Montana community with a published ZIP code list, 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

Montana cities by ZIP code count

largest 25

Area codes serving Montana

406 Billings

Scope every ZIP code recorded in Montana. Source GeoNames US postal codes (2026-07 postal dump) and Census 2024 county Gazetteer (2024 Gazetteer). Updated 15 July 2026. The map outline is a convex envelope of published places, not a state boundary.