The Defense Distinguished Service Medal is a United States military award which is presented for exceptionally distinguished performance of duty contributing to the national security or defense of the United States. The medal was created on July 9, 1970 by President Richard Nixon in Executive Order 11545.
This decoration takes precedence over the Distinguished Service Medals of the separate services and is not to be awarded to any individual for a period of service for which an Army, Navy, Air Force or Coast Guard Distinguished Service Medal is awarded.