ZIP Code 59638

59638 is one of Montana's ZIP codes, delivering to addresses in Jefferson City, Jefferson County.

City: Jefferson City
County: Jefferson County
State: Montana
Prefix: 596xx

Where this code sits

59638 is part of the 596xx range, the group of codes handled by one mail processing centre. It is the only ZIP code delivering to Jefferson City.

Area codes over the same ground

Postal and telephone geography are drawn separately, so these codes cover the area 59638 delivers to without sharing its boundary.

406 Area code 406

ZIP codes nearest 59638

The ZIP codes whose reference points sit closest to 59638.
ZIP code	Distance	Delivers to
ZIP code 59634	6.9 mi	Clancy, MT
ZIP code 59631	8.7 mi	Basin, MT
ZIP code 59632	10 mi	Boulder, MT
ZIP code 59623	15 mi	Helena, MT
ZIP code 59620	16 mi	Helena, MT
ZIP code 59624	16 mi	Helena, MT
ZIP code 59626	16 mi	Helena, MT
ZIP code 59625	16 mi	Helena, MT

Straight-line distance between place reference points, not driving distance. Where a place has no Census Gazetteer point, its postal centroid is used instead.

Each point is the reference point for 59638, plotted from its record coordinates.

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

Scope ZIP code 59638. Source GeoNames US postal codes (2026-07 postal dump) and Census 2024 county Gazetteer (2024 Gazetteer). Updated 15 July 2026. A ZIP code is a set of delivery routes, not an area; the point shown is a record coordinate, not a centre.