Mason & Hanger, a Day & Zimmermann Company, is dedicated to providing architectural and engineering (A/E) services, specializing in worldwide design of secure, mission-driven facilities, proudly serving as a partner to the United States Government for nearly two centuries. Mason & Hanger is a trusted partner of the U.S. Department of Defense, Department of Defense Reserves, Department of Homeland Security, Department of State, Department of Energy, the Intelligence Community, among other government agencies critical to the U.S. National Security Mission.