The Achievement Medal is the lowest of the United States military’s non-combat meritorious service medals. The Achievement Medal was first proposed as a means to recognize the contributions of junior officers and enlisted personnel who were not be eligible to receive the higher Commendation Medal or the Meritorious Service Medal.

Each military service issues its own version of the Achievement Medal, with a fifth version authorized by the Department of Defense for joint military activity. The Achievement Medal is awarded for outstanding achievement or meritorious service not of a nature that would not warrant the award the Commendation Medal. Since the Achievement Medal is designated as an award solely for junior personnel, it is generally only awarded to officers in the pay grade of O-4 and below and enlisted personnel below the grade of E-7. Award authority rests with local commanders, granting a broad discretion to when and for what action the Achievement Medal may be awarded.

The first service to issue the Achievement Medal was the United States Navy in 1961. The medal was originally entitled the “Secretary of the Navy Commendation for Achievement Medal”, but this title was shortened in 1967 to the "Navy Achievement Medal". In 1994, to recognize United States Marines who had received the Navy Achievement Medal, the name of the decoration was officially changed to the "Navy and Marine Corps Achievement Medal".

The United States Coast Guard created its own Achievement Medal in 1967, however the U.S. Army and U.S. Air Force waited until 1981 to issue their own versions of the award. The Joint Service Achievement Medal, considered a Department of Defense decoration senior to the service department Achievement Medals, was created in 1983.

Additional awards of the Achievement Medal are denoted by oak leaf clusters, except for the Navy and Coast Guard which issues award stars. The Valor device may also be awarded for the Navy and Coast Guard versions of the Achievement Medal. The Operational Distinguishing Device may also be authorized, to the Coast Guard Achievement Medal, upon approval of the awarding authority.