A tombstone promotion is an advance in rank awarded at retirement. It is often an honorary promotion that does not include any corresponding increase in retired pay, whose only benefit is the right to be addressed by the higher rank and have it engraved on one's tombstone.
The term was originally coined to describe the one-grade retirement promotion authorized for United States Navy line officers in 1899 to induce aging American Civil War veterans to make way for younger officers. After postwar cutbacks following the Civil War and World War I, tombstone promotions were introduced to encourage early retirements and reduce the excessive number of officers recruited during wartime expansion, at the time including both the rank and retired pay of the higher grade.
Tombstone promotions are also incentives for officers to complete a full career in military communities that do not provide flag-rank opportunities. Until 1925, a lieutenant in a Navy staff corps could retire as a commodore after 40 years of service. Honorary tombstone promotions are still granted for this reason to long-serving permanent professors at the U.S. Military Academy and U.S. Air Force Academy, and to assistant judge advocates general of the Navy.
Tombstone promotions have also been granted to honor exceptional individual service, such as building the Panama Canal or commendable performance in combat. From 1925 to 1959, thousands of United States Navy, Marine Corps, Coast Guard, and Coast and Geodetic Survey officers retired with honorary one-grade promotions on the basis of combat citations awarded before the end of World War II. By May 1959, 1,222 of the 1,420 retired Navy rear admirals had never served in that grade on active duty, being captains who retired with an honorary promotion. The derisive nickname of "tombstone admiral" was sometimes used to describe these officers.