<P> The admirals of the 1860s wore the same number of stars on their shoulders as admirals of corresponding grades do today . In 1899, the navy's one admiral (Dewey) and 18 rear admirals put on the new shoulder marks, as did the other officers when wearing their white uniforms, but kept their stars instead of repeating the sleeve cuff stripes . </P> <P> During the 20th century, the ranks of the modern U.S. admiralty were firmly established . An oddity that did exist was that the navy did not have a one - star rank except briefly during World War II when Congress established a temporary war rank of commodore . The one - star rank was later established permanently in 1986 . </P> <P> U.S. law limits the number of four - star admirals that may be on active duty at any time . The total number of active - duty flag officers is capped at 160 for the Navy . For the Army, Navy, and Air Force, no more than about 25% of the service's active - duty general or flag officers may have more than two stars, and statute sets the total number of four - star officers allowed in each service . This is set at 6 four - star Navy admirals . </P> <P> Some of these slots are reserved by statute . For the Navy, the chief of naval operations, vice chief of naval operations; for the Coast Guard the commandant of the coast guard and vice commandant of the coast guard are admirals; for the Public Health Service Commissioned Corps, the Assistant Secretary for Health is an admiral if he or she holds an appointment to the regular corps . </P>

How many admirals does the us navy have