As I mentioned in our Army Enlisted Promotions article, and the Air Force Enlisted Promotions article, each year, when Congress passes the Defense Authorization Act, they tell the Marines exactly how many people can be on active duty during the year. Congress also states, by law what percentage can serve in each grade above E-4.
While there is no statutory authority to limit percentages in the ranks of E-4 and below, The Marines limit this on their own. In the Air Force and Army, promotions up to the rank of E-4 are pretty much automatic, based on time-in-service and time-in-grade. In the Marines, this is true only for promotions to the ranks of E-2 and E-3. Promotions to E-4 and above are competitive, and are based on specific vacancies within MOS's (jobs).
The Marine Corps takes the number of "slots" they have for each enlisted rank, above the rank of E-3, and allocates them to the different MOS's (enlisted jobs). In other words, MOS 123 may be allowed to have 5,000 E-4s at any point in time and 2,000 E-5s, and MOS 456 may be authorized 7,000 E-4s, and 5,000 E-5s (as a general rule, the higher the rank, the fewer positions there are).
In order to promote someone (above the rank of E-3), there must be a "vacancy." For example, if an E-9 retires in a certain MOS, that means that one E-8 can be promoted to E-9, and that opens an E-8 slot, so one E-7 can be promoted to E-8, and so-forth. If 200 E-5s get out of the Marine Corps in a particular MOS, then 200 E-4s can be promoted to E-5.
The Marine Corps has 154,348 enlisted members on active duty. Here's how it breaks down, by enlisted rank:
- Private (E-1) - 9,671 (6.3%)
- Private First Class (E-2) - 20,625 (13.4%)
- Lance Corporal (E-3) - 43,141 (30.0%)
- Corporal (E-4) - 29,578 (19.2%)
- Sergeant (E-5) - 23,019 (15.0%
- Staff Sergeant (E-6) - 14,794 (9.6%)
- Gunnery Sergeant (E-7) - 8,801 (5.7%)
- Master Sergeant/First Sergeant (E-8) - 3,306 (2.1%)
- Master Gunnery Sergeant/Sergeant Major (E-9) - 1,413 (0.9%)
Decentralized Promotions (E-2 and E-3)
Decentralized Promotions means that the unit (company) is the promotion authority. By theory, the commander decides who gets promoted and who doesn't. In actuality, because there are no quotas for promotion for E-2s and E-3s, commanders pretty much promote everyone (as long as they do their job okay and don't get into trouble) who meet the "promotion criteria." The "promotion criteria" is set by the Marine Corps to ensure that the "promotion flow" remains stable, and everyone (regardless of MOS) can expect to be promoted at the same (approximate) time-frame.
The promotion criteria for promotion to the ranks of E-2 to E-3 are:
- Private First Class (E-2) - Six months Time-In-Service (TIS) with six months Time-In-Grade (TIG)
- Lance Corporal (E-3) - Nine months TIS and eight months TIG
Like the other services, it's possible to enlist in the Marine Corps at an advanced rank for certain accomplishments, such as college credits or participation in Junior ROTC. However, while the Army allows advanced enlistment rank up to E-4, and the Air Force up to E-3, the Marines only allow advanced enlistment rank up to Private First Class (E-2).
Composite Score Promotions (E-4 and E-5)
The promotions to E-4 and above in the Marine Corps are competitive. That means there are only so many "vacancies" in each grade (above E-3) in each MOS (job).
The Marines need a system to decide, who, within each MOS are the ones to get promoted. For promotions to the ranks of Corporal (E-4) and Sergeant (E-5), the Marines use a system of composite scores.