Title	Insignia	Title	Insignia
Ensign ENS O-1		Lieutenant Junior Grade LTJG O-2
Lieutenant LT O-3		Lieutenant Commander LCDR O-4
Commander CDR O-5		Captain CAPT O-6
Rear Admiral (lower half) RDML O-7		Rear Admiral (upper half) RADM O-8
Vice Admiral VADM O-9		Admiral ADM O-10
Fleet Admiral* FADM

* The rank of Fleet Admiral has been reserved for war time use only.