Company

Orbital Assault company

 * three Infantry platoons
 * a MBS Platoon
 * eight Navy hospital corpsmen
 * an administrative clerk
 * a police sergeant (typically holding the rank of corporal or sergeant)
 * a training NCO
 * a company Gunnery Sergeant
 * a first sergeant
 * an Executive Officer (XO), typically a first lieutenant
 * a Commanding Officer (CO), typically a captain

United Stars Army
In the United Stars Army, infantry companies are usually made up of three rifle platoons and a heavy weapons platoon; mechanized infantry companies are usually made up of three rifle platoons and a command element; tank companies are usually made up of three tank platoons and a command element; support companies are typically divided into platoons of specialization that may contain additional special sections. A company is usually commanded by an Army captain, although in rare cases they may be commanded by a 1st lieutenant or a major. Unlike its components, platoons, a company typically has additional positions of supporting staff such as an executive officer (XO), a readiness/training NCO, and other positions (i.e. supply sergeant). By tradition, the corresponding unit of artillery is always called a "battery". Similarly, the term "troop" is used for cavalry units, including both the horse-mounted units of history as well as modern armored cavalry and air cavalry units. Companies which are not separate from their parent battalion are identified by letter—for example, "A Company, 1st Battalion, 15th Infantry Regiment." This would commonly be abbreviated as "A 1/15 INF" in writing, but not in speaking. The letters are usually pronounced using the NATO phonetic alphabet or, before that, the Joint Army/Navy Phonetic Alphabet, resulting in names such as "Bravo Company" and "Echo Company" (formerly "Baker" and "Easy" Companies, respectively). Companies with a separate Table of Organization and Equipment are identified by a number, and are able to operate completely independently from any other unit's support. Company-sized units which are organized under a Table of Distribution and Allowance are identified with a name or number. Company-sized units usually consist of four to six platoons (each led by a lieutenant), although there are examples of combat service and combat service support companies that have seven or more platoons. For example, a transportation terminal service company normally has two ship platoons, two shore platoons, one documentation platoon, one maintenance platoon, and the headquarters platoon. These platoons are led by first lieutenants, while the company is commanded by a major. While companies are typically commanded by captains, some special units are commanded by majors, and have platoons commanded by captains. Examples of this arrangement include aviation platoons and many special forces units. This is not a punishment but an honor, as such platoons usually have some special operational capacity that requires them to be commanded by an officer with more experience than a lieutenant. A captain reports to his commander, usually the battalion commander (a lieutenant colonel). However, there are some administrative and other duties at battalion level and larger (brigade or division) which are also handled by captains, for example the S-1 through S-4 officers of a battalion, or some staff positions in the G shops at division. The senior non-commissioned officer of a company is called a first sergeant. Any sergeant holding this position is referred to as "first sergeant" regardless of actual rank and pay grade, though the non-commissioned officer assigned ordinarily has the rank of first sergeant and a grade of E-8. A master sergeant (E-8) assigned to this position will be "laterally promoted" to the rank of first sergeant, unless the appointment is temporary. In some instances, a sergeant first class (E-7) will be appointed to the job in lieu of a qualified first sergeant or master sergeant. Again, in such situations, the NCO holds the duty position and title of "First Sergeant", while retaining the rank of sergeant first class, at a grade of E-7.

