ZIP Code 20634

20634 is one of Maryland's ZIP codes, delivering to addresses in Great Mills, St. Mary's County.

City: Great Mills
County: St. Mary's County
State: Maryland
Prefix: 206xx

Where this code sits

20634 is part of the 206xx range, the group of codes handled by one mail processing centre. It is the only ZIP code delivering to Great Mills.

Area codes over the same ground

Postal and telephone geography are drawn separately, so these codes cover the area 20634 delivers to without sharing its boundary.

ZIP codes nearest 20634

The ZIP codes whose reference points sit closest to 20634.
ZIP code	Distance	Delivers to
ZIP code 20653	2.6 mi	Lexington Park, MD
ZIP code 20619	3.0 mi	California, MD
ZIP code 20620	3.1 mi	Callaway, MD
ZIP code 20670	3.2 mi	Patuxent River, MD
ZIP code 20667	4.5 mi	Park Hall, MD
ZIP code 20688	4.6 mi	Solomons, MD
ZIP code 20629	5.3 mi	Dowell, MD
ZIP code 20692	5.4 mi	Valley Lee, 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 20634, plotted from its record coordinates.

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

Scope ZIP code 20634. 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.