ZIP Code 21758

21758 is one of Maryland's ZIP codes, delivering to addresses in Knoxville, Frederick County.

City: Knoxville
County: Frederick County
State: Maryland
Prefix: 217xx

Where this code sits

21758 is part of the 217xx range, the group of codes handled by one mail processing centre. It is the only ZIP code delivering to Knoxville.

Area codes over the same ground

Postal and telephone geography are drawn separately, so these codes cover the area 21758 delivers to without sharing its boundary.

ZIP codes nearest 21758

The ZIP codes whose reference points sit closest to 21758.
ZIP code	Distance	Delivers to
ZIP code 21716	2.7 mi	Brunswick, MD
ZIP code 21715	2.7 mi	Brownsville, MD
ZIP code 21718	3.3 mi	Burkittsville, MD
ZIP code 21755	5.9 mi	Jefferson, MD
ZIP code 21779	6.6 mi	Rohrersville, MD
ZIP code 25425	6.7 mi	Harpers Ferry, WV
ZIP code 21756	7.8 mi	Keedysville, MD
ZIP code 21777	7.9 mi	Point Of Rocks, MD

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 21758, plotted from its record coordinates.

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

Scope ZIP code 21758. 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.