<P> In this older structure, U.S. Army mechanized infantry battalions and tank battalions, for tactical purposes, task - organized companies to each other, forming a battalion - sized task force (TF). </P> <P> Starting in 2005--2006, the U.S. Army's mechanized and tank battalions were reorganized into combined arms battalions (CABs). Tank battalions and mechanized infantry battalions no longer exist . These new combined arms battalions are modular units, each consisting of a headquarters company, two mechanized infantry companies, two armor companies, and a forward support company attached from the battalion's parent brigade support battalion . This new structure eliminated the need to task - organize companies between battalions; each combined arms battalion was organically composed of the requisite companies . At a higher level, each armored brigade (formerly designated as a heavy brigade) is now composed of three CABs (vs. the two CABs of a former heavy brigade), an armored reconnaissance squadron, a fires battalion (field artillery), a brigade engineer battalion (BEB), and a brigade support battalion (BSB). </P> <P> A United States Marine Corps battalion includes the battalion headquarters, consisting of the commanding officer (usually a lieutenant colonel, sometimes a colonel), an executive officer (the second - in - command, usually a major), the sergeant major, and the executive staff (S - 1 through S - 4 and S - 6). The battalion headquarters is supported by a headquarters and service company (battery). A battalion usually contains two to five organic companies (batteries in the artillery), with a total of 500 to 1,200 Marines in the battalion . A regiment consists of a regimental headquarters, a headquarters company (or battery), and two to five organic battalions (Marine infantry regiments--three battalions of infantry; Marine artillery regiments--three to five battalions of artillery; Marine combat logistics regiments--one to three combat logistics battalions). In the U.S. Marine Corps, the brigade designation is used only in "Marine Expeditionary Brigade" (MEB). An MEB is one of the standard Marine Air - Ground Task Forces (MAGTF), is commanded by a brigadier general or major general, and consists of command element, a ground combat element (usually one reinforced Marine infantry regiment), an aviation combat element (a reinforced Marine aircraft group including rotary wing, fixed wing, and tiltrotor aircraft), and a combat logistics element (a Marine combat logistics regiment, which includes naval construction forces (Seabees) and naval medical elements). </P> <P> In the U.S. Marine Corps, an infantry or "rifle" battalion typically consists of a headquarters and service company, three rifle, or "line", companies (designated alphabetically A through M depending upon which battalion of the parent regiment to which they are attached) and a weapons company . Weapons companies do not receive a letter designation . Marine infantry regiments use battalion and company designations as described above under World War II, with company letters D, H, and M not normally used but rather held in reserve for use in augmenting a fourth rifle company into each battalion as needed . </P>

How many marines are there in a battalion