ZIP Code 21771

21771 is one of Maryland's ZIP codes, delivering to addresses in Mount Airy, Frederick County.

City: Mount Airy
County: Frederick County
State: Maryland
Prefix: 217xx

Where this code sits

21771 is part of the 217xx range, the group of codes handled by one mail processing centre. It is the only ZIP code delivering to Mount Airy.

Mount Airy Maryland ZIP codes →

Area codes over the same ground

Postal and telephone geography are drawn separately, so these codes cover the area 21771 delivers to without sharing its boundary.

ZIP codes nearest 21771

The ZIP codes whose reference points sit closest to 21771.
ZIP code	Distance	Delivers to
ZIP code 21770	4.8 mi	Monrovia, MD
ZIP code 21774	5.7 mi	New Market, MD
ZIP code 21792	6.0 mi	Unionville, MD
ZIP code 21765	6.4 mi	Lisbon, MD
ZIP code 21797	6.4 mi	Woodbine, MD
ZIP code 21762	7.6 mi	Libertytown, MD
ZIP code 21754	7.9 mi	Ijamsville, MD
ZIP code 20872	8.0 mi	Damascus, 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 21771, plotted from its record coordinates.

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

Scope ZIP code 21771. 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.