In 1877, Navy officers of the Medical, Pay, and Engineer Corps, chaplains, professors of mathematics, and naval constructors were authorized to retire with the relative rank but not the pay of a commodore, if they retired after 45 years of service, or at the age of 62 after at least 40 years of service. This was meant to reward long service in a staff corps with a higher rank on the retired list than could be attained on the active list, since the only staff corps officers with ranks higher than captain were the bureau chiefs. Staff corps officers continued to retire with the rank of commodore even after the grade was abolished in 1899. In 1916, the rank of rear admiral was established on the active list for all staff corps officers except chaplains and professors of mathematics, weakening the original rationale for this promotion by making flag rank more attainable. The retirement age was increased to 64 and staff corps officers were given the pay of their rank, so officers who retired with the rank of commodore now received its retired pay as well.
