The first recognized medals of the U.S. Army appeared during the American Civil War and were generally issued by local commanders on an unofficial basis. The Medal of Honor was the first award to be established in regulations as a permanent Army decoration, complete with benefits. The Medal of Honor is the only Civil War era award which has survived as a decoration into the modern age.

Such awards may also be issued to members of other military services, provided such service members are performing duty under a Navy or Marine Corps command. Likewise, a Navy or Marine Corps service member may receive medals and decorations of another military branch, if cross assigned to a command of the respective service. All Navy and Marine Corps members are eligible to receive Inter-service medals of the United States military inter-service decorations as well as Authorized foreign decorations of the United States military approved foreign awards and international decorations..

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Those National Guard members who subsequently serve in an active reserve component of the United States Army or United States Air Force may continue to wear and display such decorations on a military uniform. National Guard members who are discharged, and subsequently join the United States Navy, United States Marine Corps, or United States Coast Guard, are prohibited from displaying National Guard decorations since there is no National Guard equivalent to any of the United States sea services.