21106

21106 is a five-digit ZIP code used by the United States Postal Service (USPS) to designate a specific geographic area for mail delivery within the state of Maryland, United States. ZIP codes are part of a nationwide system introduced by the USPS in 1963 to improve mail sorting and delivery efficiency; they identify routes and service areas rather than strict political boundaries. The 21106 designation is associated with a defined area within Maryland and is used by residents and businesses for postal addresses, as well as by data analysts, marketers, and planners to identify locations and characteristics of the area.

As with other ZIP codes, the exact boundaries of 21106 can change over time due to factors such as population growth, annexations, or changes in postal routing. The code may cross municipal or county lines in some cases, and multiple post offices can share responsibility for delivery within the area. For current and precise boundary definitions, population estimates, and area characteristics, official resources from the USPS or the U.S. Census Bureau should be consulted.