Second Lieutenant (2ndLt)(O1)
Second Lieutenant is the first rank a commissioned officer makes when joining the U.S. Marine Corps. Due to their inexperience, they are often guided by senior officers or warrant officers. Nicknames for Second Lieutenant include "nugget" and "butterbar" due to their insignia being a single gold bar.
First Lieutenant (1stLt)(O2)
The rank of First Lieutenant is usually automatically attained after a Marine has served for two years as a 2ndLt. Promotion to First Lieutenant generally leads to bigger paychecks, more responsibility, and future chances for promotion.
Captains in the Marine Corps are responsible for individual companies, and act as Company Commander for 62 to 190 Marines. Captains are generally promoted from Lieutenants. They are in charge of the tactical and everyday operations of their company, and are often assisted by junior commissioned and non-commissioned officers.
Major’s in the U.S. Marine Corps are typically recruited from the rank of Captain. They are considered to be a field grade.
Lieutenant Colonel (LtCol)(O5)
Lieutenant Colonel’s are the second field officer grade in the U.S. Marine Corps. They command between 300 and 1,000 Marines at a given time and are assisted by one Major, junior commissioned officers, and one Command Sergeant Major as an enlisted advisor. It typically takes 16 to 22 years to reach the rank of Lieutenant Colonel.
Colonels in the U.S. Marine Corps typically go to the Army War College in Pennsylvania or the Marine Corps War College in Virginia. It typically takes 21 to 23 years to reach this rank, and it is considered to be the final step before reaching the General Officer ranks.
Brigadier General (BGen)(O7)
The lowest of the General Officer ranks, Brigadier Generals in the Marine Corps are one-star General Officers. They preside over 10,000 to 15,000 Marines and are in charge of tactical planning and coordination of operations. Brigadier Generals must retire five years after achieving the rank or once 30 years cumulative service has been reached, whichever comes first. The only exception to this rule is to receive a promotion.
Major General (MajGen)(O8)
A two star general, Major Generals are promoted via a strict process of multiple nominations and reviews. Major Generals must retire after five years in the rank or after 35 years of service unless they are promoted.
Lieutenant General (LtGen)(O9)
Considered a temporary rank, Lieutenant Generals retire once their active tour of duty or service comes to an end. They must retire after 38 years in the service or a month after turning 64. Lieutenant Generals can extend their status only through an act of Congress.
Generals in the Marine Corps are the highest ranking officers in the branch. The Marine Corps can have a maximum of 60 general officers, and only three may be four-star Generals. Generals are nominated by the President and are confirmed by the Senate. They must retire after 40 years of service or after they turn 64.