The Distinguished Service Medal (DSM) is a military decoration awarded to personnel of the Australian Defence Force for distinguished leadership in action. The DSM was introduced in 1991 and is the second highest distinguished service decoration in the Australian Honours System. Recipients of the Distinguished Service Medal are entitled to use the post-nominal letters "DSM". Since its inception 125 have been awarded, which includes three Bars, with the most recent being announced in the 2012 Queen's Birthday Honours List.