General and Flag Officers in the U.S. Armed Forces: Background and Considerations for Congress [Updated February 1, 2019] [open pdf - 1MB]
"In the exercise of its constitutional authority over the Armed Forces, Congress has enacted an array of laws which govern important aspects of military officer personnel management, including appointments, assignments, grade structure, promotions, and separations. Some of these laws are directed specifically at the most senior military officers, known as general and flag officers (GFOs). Congress periodically reviews these laws and considers changes as it deems appropriate. Areas of congressional interest have included the number of GFOs authorized, the proportion of GFOs to the total force, compensation levels of GFOs, and duties and grades of certain GFOs. [...] This report provides an overview of active duty GFOs in the United States Armed Forces-- including authorizations, duties, and compensation--historical trends in the proportion of GFOs relative to the total force, criticisms and justifications of GFO to total force proportions, and statutory controls. National Guard and Reserve GFOs are not addressed in this report, unless they are serving on active duty in a manner that counts against the active duty caps on GFOs."
CRS Report for Congress, R44389
Congressional Research Service: https://crsreports.congress.gov/