ZIP code 04421 is officially located in the state of Maine, primarily serving the city of Castine. It falls under the administrative jurisdiction of Hancock County. When planning mail delivery, logistics routing, or demographic research, 04421 operates within the Eastern Time (ET) timezone and supports the 508 area codes.
According to the latest US Census Bureau and American Community Survey (ACS) datasets, the total population residing within the 04421 ZIP Code Tabulation Area is approximately 16,608. Understanding local economics is critical for market analysis; the median household income in this postal area sits at $97,421.