The Australian Defence Medal recognises Australian Defence Force personnel who have efficiently completed either 
an initial enlistment period, or four years service, whichever is the lesser. To be qualify service was after 3 September 1945.

There are however exceptions and these include thse did not complete the qualifying period as they died in service,were medically unfit and so were discharged,or resigned from the Australian Defence Force due to the termination policy that existed.