ZIP Code 21788

21788 is one of Maryland's ZIP codes, delivering to addresses in Thurmont, Frederick County.

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

Where this code sits

21788 is part of the 217xx range, the group of codes handled by one mail processing centre. It is the only ZIP code delivering to Thurmont.

Thurmont Maryland ZIP codes →

Area codes over the same ground

Postal and telephone geography are drawn separately, so these codes cover the area 21788 delivers to without sharing its boundary.

ZIP codes nearest 21788

The ZIP codes whose reference points sit closest to 21788.
ZIP code	Distance	Delivers to
ZIP code 21778	3.7 mi	Rocky Ridge, MD
ZIP code 21780	6.2 mi	Sabillasville, MD
ZIP code 21775	6.4 mi	New Midway, MD
ZIP code 21759	6.4 mi	Ladiesburg, MD
ZIP code 21727	6.7 mi	Emmitsburg, MD
ZIP code 21757	7.0 mi	Keymar, MD
ZIP code 21798	7.7 mi	Woodsboro, MD
ZIP code 21719	7.8 mi	Cascade, 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 21788, plotted from its record coordinates.

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

Scope ZIP code 21788. 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.