A rear admiral in the U.S. Navy is designated as either an upper-half rear admiral or a lower-half rear admiral, with different pay rates for each rank. An upper-half rear admiral is a two-star rank and a lower-half rear admiral is a one-star rank. Each rank is addressed as "rear admiral" verbally, although rank distinctions are made in written correspondence. The United States Coast Guard shares identical ranks and similar insignias as the Navy, although the practical highest ranks differ in title --- chief of naval operations in the Navy and commandant of the Coast Guard.
The term "rear admiral" has its origins in 18th century naval operations. An admiral commanded a fleet from a ship positioned in the centre of a formation and his second in command, a vice admiral, commanded from the front of the fleet and absorbed the brunt of battle. The third in command operated from the rear of the fleet, thus earning the moniker "rear admiral." The U.S. Navy, Coast Guard, Public Health Service Commissioned Corps and the National Oceanic and Atmospheric Administration all employ uniformed commissioned officers at the rank of rear admiral.
Rear Admiral, Lower Half
A rear admiral lower half, or RDML, is designated as pay grade O-7, equal in pay grade to a brigadier --- one-star --- general in the Army, Marine Corps and Air Force. The 2011 monthly pay rate is £5,147.4 for rear admirals lower half with two years or less service. The pay rates increase to £5,386.6, £5,497.2, £5,585.1, £5,744.5 and £5,901.8 for service over two, three, four, six and eight years, respectively. For service over 10 years, the monthly salary is £6,083.8; for more than 12 years it's £6,265.1, over 14 years the monthly pay is £6,447.0, and for more than 16 years service the rate is £7,018.8. For more than 18, 20, 22 and 24 years of service the salary is £7,501.4. After 26 and 28 years the rate is £7,539.6, and the monthly rate is £7,690.6 for more than 30 years service.
Rear Admiral, Upper Half
A rear admiral upper half --- RADM and pay grade O-8 --- earns the same pay as a major general in the Army, Air Force and Marine Corps. Two-star rear admirals make a monthly salary of £6,194.9 with two years or less service, and £6,397.7, £6,532.5, £6,570.1, £6,738.2 and £7,018.8 for more than two, three, four, six and eight years of service, respectively. For more than 10, 12, 14, 16 and 18 years in the military, rear admirals upper half earn £7,084.3, £7,350.7, £7,427.1, £7,656.8 and £7,989.1 per month, respectively. After 20 years the salary is £8,295.5. For more than 22, 24, 26 and 28 years of service, the monthly salary is £8,500.2. For more than 30 and 32 years the pay is £8,712.8 a month. After 34 years the monthly salary is £8,930.6.
A vice admiral, pay grade O-9 and equivalent to three-star or lieutenant general in the Air Force, Marines and Army, has a 20-year monthly salary of £8,755.3 and a 40-year rate of £10,860.5 a month. An admiral, chief of naval operations, is pay grade O-10, equivalent to a four-star general. He makes £10,010.5 per month at 20 years and £12,308.9 a month after 40 years. Admirals and vice admirals must serve 20 years to achieve their ranks.
2012 Pay Raises
In June 2011, the U.S. Senate Armed Services Committee authorised a 1.6 per cent pay increase for all military personnel for 2012.
Rear admirals, like all military personnel, are eligible for housing allowances and other pay considerations, such as uniform allowances, career sea pay, hazardous-duty pay and other forms of compensation.