ZIP code 21918 is officially located in the state of Maryland, primarily serving the city of Conowingo. It falls under the administrative jurisdiction of Cecil County. When planning mail delivery, logistics routing, or demographic research, 21918 operates within the Eastern Time (ET) timezone and supports the 617 area codes.
According to the latest US Census Bureau and American Community Survey (ACS) datasets, the total population residing within the 21918 ZIP Code Tabulation Area is approximately 4,117. Understanding local economics is critical for market analysis; the median household income in this postal area sits at $46,918.