10 U.S.C. § 8297: Additional awards

Not more than one Navy cross, distinguished-service medal, silver star medal, distinguished flying cross, or Navy and Marine Corps Medal may be awarded to a person. However, for each succeeding act or service that would otherwise justify the award of such a medal or cross, the President may award a suitable bar, emblem, or insignia to be worn with the decoration and corresponding rosette or other device.