ZIP Code 21648

21648 is one of Maryland's ZIP codes, delivering to addresses in Madison, Dorchester County.

City: Madison
County: Dorchester County
State: Maryland
Prefix: 216xx

Where this code sits

21648 is part of the 216xx range, the group of codes handled by one mail processing centre. It is the only ZIP code delivering to Madison.

Area codes over the same ground

Postal and telephone geography are drawn separately, so these codes cover the area 21648 delivers to without sharing its boundary.

ZIP codes nearest 21648

The ZIP codes whose reference points sit closest to 21648.
ZIP code	Distance	Delivers to
ZIP code 21669	3.2 mi	Taylors Island, MD
ZIP code 21677	3.6 mi	Woolford, MD
ZIP code 21622	5.2 mi	Church Creek, MD
ZIP code 21613	10 mi	Cambridge, MD
ZIP code 21634	11 mi	Fishing Creek, MD
ZIP code 21626	12 mi	Crapo, MD
ZIP code 20657	13 mi	Lusby, MD
ZIP code 20685	15 mi	Saint Leonard, 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 21648, plotted from its record coordinates.

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

Scope ZIP code 21648. 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.