Oldtown, MD

ZIP code 21555 is located in Fort Detrick, Maryland, known for its cutting-edge biological research and development facilities. This area is home to the United States Army Medical Research Institute of Infectious Diseases (USAMRIID) and the National Interagency Confederation for Biological Research (NICBR). Additionally, Fort Detrick houses the Fort Detrick Forest Glen Annex and plays a crucial role in national defense and medical research.