Service members in pay grades E-1 through E-3 are usually either in some kind of training status or on their initial assignment. The training includes the basic training phase where recruits are immersed in military culture and values and are taught the core skills required by their service component.

Basic training is followed by a specialized or advanced training phase that provides recruits with a specific area of expertise or concentration. In the Army and Marines, this area is called a military occupational specialty; in the Navy it is known as a rate; and in the Air Force it is simply called an Air Force specialty.

ARMY -- * For rank and precedence within the Army, specialist ranks immediately below corporal. Among the services, however, rank and precedence are determined by pay grade.

NAVY/COAST GUARD -- *A specialty mark in the center of a rating badge indicates the wearer's particular rating. ** Gold stripes indicate 12 or more years of good conduct. *** 1. Master chief petty officer of the Navy and fleet and force master chief petty officers. 2. Command master chief petty officers wear silver stars. 3. Master chief petty officers wear silver stars and silver specialty rating marks.

The U.S. Coast Guard is a part of the Department of Transportation in peacetime and the Navy in times of war. Coast Guard rank insignia are the same as the Navy except for color and the seaman recruit rank, which has one stripe.

Leadership responsibility significantly increases in the mid-level enlisted ranks. This responsibility is given formal recognition by use of the terms noncommissioned officer and petty officer. An Army sergeant, an Air Force staff sergeant, and a Marine corporal are considered NCO ranks. The Navy NCO equivalent, petty officer, is achieved at the rank of petty officer third class.

At the E-8 level, the Army, Marines and Air Force have two positions at the same pay grade. Whether one is, for example, a senior master sergeant or a first sergeant in the Air Force depends on the person's job. The same is true for the positions at the E-9 level. Marine Corps master gunnery sergeants and sergeants major receive the same pay but have different responsibilities. All told, E-8s and E-9s have 15 to 30 years on the job, and are commanders' senior advisers for enlisted matters.
A third E-9 element is the senior enlisted person of each service. The sergeant major of the Army, the sergeant major of the Marine Corps, the master chief petty officer of the Navy and the chief master sergeant of the Air Force are the spokespersons of the enlisted force at the highest levels of their services.

Officer ranks in the United States military consist of commissioned officers and warrant officers. The commissioned ranks are the highest in the military. These officers hold presidential commissions and are confirmed at their ranks by the Senate. Army, Air Force and Marine Corps officers are called company grade officers in the pay grades of O-1 to O-3, field grade officers in pay grades O-4 to O-6 and general officers in pay grades O-7 and higher. The equivalent officer groupings in the Navy are called junior grade, mid-grade and flag.

Warrant officers hold warrants from their service secretary and are specialists and experts in certain military technologies or capabilities. The lowest ranking warrant officers serve under a warrant, but they receive commissions from the president upon promotion to chief warrant officer 2. These commissioned warrant officers are direct representatives of the president of the United States. They derive their authority from the same source as commissioned officers but remain specialists, in contrast to commissioned officers, who are generalists. There are no warrant officers in the Air Force.