To qualify for a Defence Force Service Medal, a member is required to complete 15 years of efficient remunerated service prior to 20 April 1999 and must have been serving on or after 14 February 1975.
 
A minimum of 12 years in the Regular Forces and up to 3 years in the Reserve (to total 15 years) can be counted towards the medal only.
 
Clasps are awarded for each further periods of 5 years efficient regular service. Reserve service and Continuous Full Time service in the Reserve does not qualify towards clasps for this medal.
 
From 20 April 1999 the Defence Force Service Medal was replaced by the Defence Long Service Medal. Qualifying service for clasps can be accrued after 19 April 1999.
 
Clasps
The clasp is a cupro-nickel bar with the Royal Cypher flanked by sprigs of wattle in the centre.