Vice admiral ( United States ) In the United States Navy , the United States Coast Guard , the United States Public Health Service Commissioned Corps , the National Oceanic and Atmospheric Administration Commissioned Corps , and the United States Maritime Service , vice admiral ( VADM ) is a three - star flag officer , with the pay grade of O - 9 . Vice admiral ranks above rear admiral and below admiral . Vice admiral is equivalent to the rank of lieutenant general in the other uniformed services . Statutory limits . U . S . Code of law explicitly limits the total number of vice admirals that may be on active duty at any given time . The total number of active - duty flag officers is capped at 216 for the Navy . For the Navy , no more than 16 . 3 % of the service ' s active - duty flag officers may have more than two stars . Some of these slots are reserved by statute . For example the Surgeon General of the United States Navy is a vice admiral . The Judge Advocate General of the Navy is a vice admiral in the Navy or a lieutenant general in the Marine Corps ; the Surgeon General of the United States is also vice admiral in the Public Health Service Commissioned Corps . Officers serving in certain intelligence positions are not counted against either limit , including the Deputy Director of the Central Intelligence Agency . The President may also add vice admirals to the Navy if they are offset by removing an equivalent number of three - star officers from other services . Finally , all statutory limits may be waived at the President ' s discretion during time of war or national emergency . Appointment and tour length . The three - star grade goes hand - in - hand with the position of office it is linked to , so the rank is temporary . Officers may only achieve three - star grade if they are appointed to positions that require the officer to hold such a rank . Their rank expires with the expiration of their term of office , which is usually set by statute . Vice admirals are nominated for appointment by the President from any eligible officers holding the rank of rear admiral ( lower half ) or above , who also meet the requirements for the position , under the advice and / or suggestion of their respective department secretary , service secretary , and if applicable , the joint chiefs . The nominee must be confirmed via majority vote by the Senate before the appointee can take office and thus assume the rank . The standard tour length for most vice admiral positions are three years but some are set four or more years by statute . Note : Extensions of the standard tour length can be approved , within statutory limits , by their respective service secretaries , the Secretary of Defense , the President , and / or Congress but these are rare , as they block other officers from being promoted . Some statutory limits under the U . S . Code can be waived in times of national emergency or war . Three - star ranks may also be given by act of Congress but this is extremely rare . Retirement . Other than voluntary retirement , statute sets a number of mandates for retirement . Three - star officers must retire after 38 years of service unless appointed for promotion or reappointed to grade to serve longer . Otherwise all flag officers must retire the month after their 64th birthday . The Secretary of Defense , however , can defer a three - star officer ' s retirement until the officer ' s 66th birthday and the President can defer it until the officer ' s 68th birthday . Flag officers typically retire well in advance of the statutory age and service limits , so as not to impede the upward career mobility of their juniors . Since there are a finite number of three - star slots available to each service , typically one officer must leave office before another can be promoted . Maintaining a three - star rank is a game of musical chairs ; once an officer vacates a position bearing that rank , he or she has no more than 60 days to be appointed or reappointed to a job of equal or higher importance before he or she must involuntarily retire . Historically , officers leaving three - star positions were allowed to revert to their permanent two - star ranks to mark time in lesser jobs until statutory retirement , but now such officers are expected to retire immediately to avoid obstructing the promotion flow . United States Maritime Service . Although it exists only as an auxiliary , the United States Maritime Service does maintain the rank of vice admiral . No USMS officer is currently commissioned at this rank . The last USMS officer to hold the grade was Joseph D . Stewart , who retired in 2008 . Even though the Martime Service is an auxiliary service , the grade is appointed by the President via the Secretary of Transportation , with the consent of the Senate , making it a federally recognized rank with corresponding paygrade . However , their pay differs from the other federal uniformed service pay scale .