Instituted on the 20th April 1982 by Queen Elizabeth II for Officers and other ranks. The Defence Force Service Medal is struck in cupro-nickel. It is awarded for 15 years long service, and replaces the National Medal and other LSGC Medals, although they may be worn together providing the criteria has been met to do so. Clasps for additional 5 years service are added to the ribbon.

Approximately 35,000 medals have been isssued to Australians.