Field Army insignia of the United States Army
Shoulder sleeve insignia (SSI) are cloth emblems worn on the shoulders of US Army uniforms to identify the primary headquarters to which a soldier is assigned. The highest field organization in the United States Army currently consists of field armies, which were once combined into army groups. Currently, Army components of unified combatant commands wear the SSI of field armies of the past (for example, USARCENT, the Army component of CENTCOM, wears the SSI of Third Army).
US Army Groups
US Field Armies
Allied Armies (World War II)
18th Allied Army Group (1942-1943)