ZIP Code 20657 is located in the county of Calvert in the state of Maryland. 20657 ZIP Code is spread between the coordinates of +38.3676802 Latitude and -76.42881314 Longitude. 20657 ZIP Code is part of the 410 area code. There is 1 postal office in zip code 20657.
On the below highlighted section you can find the cities which the US Post Office accepts for ZIP code 20657. Always when you mail a package or a letter, be attentive to mention the preferred or acceptable cities. Using any city in the list of unacceptable cities may result in unforseen delays.