A medium-range ballistic missile (MRBM) is a type of ballistic missile with medium range, this last classification depending on the standards of certain organizations. Within the U.S. Department of Defense, a medium range missile is defined by having a maximum range of between 1,000 and 3,000 km. In modern terminology, MRBMs are part of the wider grouping of theatre ballistic missiles, which includes any ballistic missile with a range of less than 3,500 km.