The Defence Long Service Medal may be awarded to a member who has, on or after 14 February 1975, completed 15 years qualifying remunerated service in the Australian Defence Force. This includes efficient service in Permanent and Reserve Forces. Clasps are awarded for each further periods of five years efficient service.
The regulations state that members are not entitled to have a Defence Force service award and the DLSM at the same time. The Defence Force service awards are:
Members wishing to have previously unrecognised service counted toward the DLSM are required to return the Defence Force service award before the DLSM is issued.
The medal is cupronickel. The obverse has the Joint Service Emblem surrounded by two sprays of wattle leaves and blossom.
The reverse has a central horizontal panel surrounded by the inscription 'FOR SERVICE IN THE AUSTRALIAN DEFENCE FORCE'.
The ribbon has a central panel of seven alternating blue and gold stripes flanked by blue stripes gold edges. The colours and design reflect those of the replaced medals.
The clasp is a bar with the Royal Cypher flanked by sprigs of wattle in the centre.
When the ribbon is worn alone a clasp is indicated by the addition of a round rosette or a Federation Star.
The first four clasps to the medal are indicated by rosettes. These are replaced by a single Federation Star for the fifth clasp. Additional Federation Star emblems are added for subsequent clasps.