The National Defense Service Medal will be awarded to all persons in the Naval service who served on active duty at any time between 27 June 1950 and 27 July 1954. [Also see below]
All personnel serving on active duty during the above period are eligible for this award with the exception of reserve personnel on active duty for training, reserve personnel on short tours of active duty to serve on boards, courts, commissions, etc., and any persons ordered to active duty who, on physical examination incident thereto, are disqualified and immediately released from active duty.(Executive Order No. 10448 of 22 April 1953 and Department of Defense Directive 1348.7 of 15 July 1953.)
Following the precedent of the pre-World War II American Defense Service Medal, the National Defense Service Medal has been worn by three "generations" of sailors and Marines for three distinct periods of our military history.
Designed by the Army's Institute of Heraldry in Cameron Station, Va., the first medals were issued during the Korean War era and note active federal service performed as part of normal extended duty between 27 June 1950 and 27 July 1954, both dates inclusive.
The next period of eligibility coincided with that of the Vietnam War, with duty between 01 Jan. 1961 and 14 Aug. 1974 being the criteria for the award, both dates inclusive. This amended period of eligibility was established by Executive Order 11265 of 11 January 1966.
The most recent period of award encompasses Southwest Asia service, with eligibility beginning 02 Aug. 1990, based on Executive Order 12776 from President George Bush on 18 October 1991. The terminal eligibility date for this period later was set as 30 Nov. 1995.
Interestingly, because of the expanded role of military reservists in "Desert Shield" and "Desert Storm," President Bush's executive order extended the medal's award to those drilling members of the Selected Reserve.
Sailors and Marines with active duty in two or more of the periods wear a small bronze service star on the ribbon for each additional eligibility period.
Any member of the Naval Reserve who, after 31 December 1960, becomes eligible for the award of the Armed Forces Expeditionary Medal or the Vietnam Service Medal, is also eligible for award of the National Defense Service Medal.
Source: 1953 U.S. Navy Awards Manual, current Awards Manual
21 June 1998