ZIP Code 40121

40121 is one of Kentucky's ZIP codes, delivering to addresses in Fort Knox, Hardin County.

City: Fort Knox
County: Hardin County
State: Kentucky
Prefix: 401xx

Where this code sits

40121 is part of the 401xx range, the group of codes handled by one mail processing centre. Fort Knox is served by 2 ZIP codes in total.

Area codes over the same ground

Postal and telephone geography are drawn separately, so these codes cover the area 40121 delivers to without sharing its boundary.

502 Area code 502

ZIP codes nearest 40121

The ZIP codes whose reference points sit closest to 40121.
ZIP code	Distance	Delivers to
ZIP code 40122	0.8 mi	Fort Knox, KY
ZIP code 40155	3.9 mi	Muldraugh, KY
ZIP code 40175	3.9 mi	Vine Grove, KY
ZIP code 40160	4.6 mi	Radcliff, KY
ZIP code 40177	7.1 mi	West Point, KY
ZIP code 40162	10 mi	Rineyville, KY
ZIP code 40108	10 mi	Brandenburg, KY
ZIP code 40117	11 mi	Ekron, KY

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 40121, plotted from its record coordinates.

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

Scope ZIP code 40121. 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.