Field army 集团军

![The unit flag of the Sixth United States Army. The distinguishing flag of a United States army is bicolored, white over red, measuring 91.4 centimeters (36 inches) hoist by 121.9 centimeters (48 inches) fly, with gold fringe. In the center is a rendering of the army's shoulder-sleeve insignia, measuring 38.1 centimeters (15 inches) in height.[1]](/uploads/202501/13/Sixth_United_States_Army_flag2628.gif)

A field army (or numbered army or simply army) is a military formation in many armed forces, composed of two or more corps and may be subordinate to an army group. Likewise, air armies are equivalent formation within some air forces. A field army is composed of 100,000 to 150,000 troops.