This article concerns the United States Army Distinguished Service Medal. Please see "Distinguished Service Medal" for other U.S. versions of the Distinguished Service Medal.
The Distinguished Service Medal (DSM) is a military award of the United States Army that is presented to any person who, while serving in any capacity with the United States military, has distinguished himself or herself by exceptionally meritorious service to the Government in a duty of great responsibility. The performance must be such as to merit recognition for service that is clearly exceptional. Exceptional performance of normal duty will not alone justify an award of this decoration.
Separate Distinguished Service Medals exist for the different branches of the military as well as a fifth version of the medal which is a senior award of the United States Department of Defense. The Army version of the Distinguished Service Medal is typically referred to simply as the "Distinguished Service Medal" while the other branches of service use the service name as a prefix.
For service not related to actual war, the term "duty of a great responsibility" applies to a narrower range of positions than in time of war, and requires evidence of conspicuously significant achievement. However, justification of the award may accrue by virtue of exceptionally meritorious service in a succession of high positions of great importance.
Awards may be made to persons other than members of the Armed Forces of the United States for wartime services only, and then only under exceptional circumstances, with the express approval of the President in each case.

Design of the Distinguished Service Medal
The Distinguished Service Medal was authorized by Presidential Order dated January 2, 1918, and confirmed by Congress on July 9, 1918. It was announced by War Department General Order No. 6, January 12, 1918, with the following information concerning the medal: "A bronze medal of appropriate design and a ribbon to be worn in lieu thereof, to be awarded by the President to any person who, while serving in any capacity with the Army shall hereafter distinguish himself or herself, or who, since April 6, 1917, has distinguished himself or herself by exceptionally meritorious service to the Government in a duty of great responsibility in time of war or in connection with military operations against an armed enemy of the United States." The Act of Congress on July 9, 1918, recognized the need for different types and degrees of heroism and meritorious service and included such provisions for award criteria. The current statutory authorization for the Distinguished Service Medal is Title 10, United States Code, Section 3743.
Among the first awards of the Distinguished Service Medal for service in World War I were those presented to the Commanding Officers of the Allied Armies: General Pershing of the United States, Marshals Foch and Joffre and General Pétain of France, Field Marshal Haig of the United Kingdom, General Currie of Canada, General Monash of Australia, General Diaz of Italy and General Gillain of Belgium. More than 2,000 awards were made during World War I, and by the time the United States entered World War II, approximately 2,800 awards had been made. From July 1, 1941 to June 6, 1969, when the Army stopped publishing awards of the DSM in Department of the Army General Orders, over 2,800 further awards were made (George H. Apgar, Awards of the US Army Distinguished Service Medal 1942-1969, 1995 Planchet Press).
Because the Army Distinguished Service Medal is principally awarded to general officers, a list of notable recipients would include nearly every general and admiral since 1918, many of whom received multiple awards, as well as a few civilians prominent for their contributions to national defense. Among notable recipients below flag rank are: X-1 test pilot Chuck Yeager and X-15 test pilot Robert M. White, who both received the DSM as U.S. Air Force majors; Air Force Major Rudolph Anderson, the U-2 pilot shot down during the Cuban Missile Crisis; director Frank Capra, decorated in 1945 as an Army colonel; Col. Wendell Fertig, who led Filipino guerrillas behind Japanese lines; and Col. (later Major General) John K. Singlaub, who led partisan forces in the Korean War.
It should be noted that until the early 60s, United States Air Force did not have its own set of decorations, thus issued to its personnel the Army's medals and decorations.