| Army | Navy Coast Guard | Marines | Air Force | |
|---|---|---|---|---|
| O2 | First Lieutenant 1LT |
Lieutenant Junior Grade LTJG |
First Lieutenant 1st Lt. |
First Lieutenant 1st Lt. |
| O1 | Second Lieutenant 2LT |
Ensign ENS |
Second Lieutenant 2nd Lt. |
Second Lieutenant 2nd Lt. |
| W5 | Chief Warrant Officer CW5 |
Chief Warrant Officer CWO5 |
Chief Warrant Officer 5 CWO5 |
NO WARRANT |
| W4 | Chief Warrant Officer 4 CW4 |
Chief Warrant Officer 4 CWO4 |
Chief Warrant Officer 4 CWO4 |
NO WARRANT |
| W3 | Chief Warrant Officer 3 CW3 |
Chief Warrant Officer 3 CWO3 |
Chief Warrant Officer 3 CWO3 |
NO WARRANT |
| W2 | Chief Warrant Officer 2 CW2 |
Chief Warrant Officer 2 CWO2 |
Chief Warrant Officer 2 CWO2 |
NO WARRANT |
| W1 | Warrant Officer 1 WO1 |
Warrant Officer 1 WO1 |
Warrant Officer 1 WO |
NO WARRANT |
Source: http://www.defenselink.mil/specials/insignias/officers.html.
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.
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.
