The Defence Medal is awarded for six months service in a prescribed non-operational area subject to enemy air attack or closely threatened, in Australia and overseas, or for 12 months service in non-prescribed non-operational areas.

Within Australia the area is the Northern Territory, north of 14 degrees 30 minutes south, and the Torres Strait Islands between 3 September 1939 and 2 September 1945.

Overseas service includes the Middle East, east of the Suez Canal (less the period of the Syrian Campaign) or Malaya prior to the Japanese invasion on 8 December 1941.