The National Security Medal is a decoration of the United States of America officially established by President Harry S. Truman in Executive Order 10431 of January 19, 1953.

[1] On October 2, 2015, President Barack Obama amended Executive Order 10431 to award the medal to any person for distinguished achievement or outstanding contribution made in the field of national security through either exceptionally meritorious service performed in a position of high responsibility or through an act of heroism requiring personal courage of a high degree.

Any individual may recommend a potential recipient as a candidate for the award to the Executive Secretary of the National Security Council.

The National Security Medal is authorized to both civilians and personnel of the United States military and is an authorized decoration for display on active duty uniforms of the United States armed forces.

Additional decorations of the National Security Medal are denoted by a bronze oak leaf cluster.