ZIP code 21556 is officially located in the state of Maryland, primarily serving the city of Oldtown. It falls under the administrative jurisdiction of Allegany County. When planning mail delivery, logistics routing, or demographic research, 21556 operates within the Eastern Time (ET) timezone and supports the 796 area codes.
According to the latest US Census Bureau and American Community Survey (ACS) datasets, the total population residing within the 21556 ZIP Code Tabulation Area is approximately Data Not Available. Understanding local economics is critical for market analysis; the median household income in this postal area sits at $92,556.