Marine officer candidate covered in mud completes obstacle during combat endurance course at Officer Candidates School.

Officer Candidates School (OCS)

Learning to lead with honor and excellence

Where Officers Are Made

At OCS, mind, body, and character are put to the test. No candidate will earn the officer commission without demonstrating they can meet the standard found in our motto, Ductus Exemplo, Latin for “Lead by example.”

Officer Candidates School (OCS) is a 10 to 12-week program at Quantico, Virginia, where aspiring leaders face the most demanding test of their lives. Often compared to an “officer’s boot camp,” OCS is a proving ground designed to evaluate and shape the next generation of Marine Corps Officers.

Here, candidates are pushed to their limits—mentally, physically, and morally. The curriculum is built to test them in three key categories: academic knowledge, physical fitness, and leadership ability, all while being held to the Marine Corps' highest standard: Ductus Exemplo—Lead by Example.

Only those who show the fighting spirit, the discipline, and the leadership required will earn the right to lead Marines. They will earn a commission as a Second Lieutenant and proceed to The Basic School for further training.

Watch what it takes to become a Marine Officer, and explore the training that forges leaders from the ground up.

Face the Quigley. Find the Will to Succeed.

Combining water, wire, and willpower

The Quigley isn’t just an obstacle—it’s a rite of passage. This legendary OCS challenge harkens back to tough conditions in Korea and Vietnam, forcing officer candidates to crawl through flooded trenches, navigate barbed wire, and push through submerged tunnels and concrete culverts.

See the Mindset it Takes

The Path to Becoming a Marine Officer

OCS is divided into five distinct phases, each building on the last to forge Marine leaders ready for the challenges of command. As they progress, candidates are tested in everything from combat tactics and land navigation to decision-making under stress.

Officer candidates organize gear and equipment in storage racks during Phase 1 training at Officer Candidates School.

Officer candidates stand in formation holding rifles during Phase 2 drill inspection under blue sky with clouds.

Officer candidate uses compass and map to navigate during Phase 3 land navigation training exercise.

Officer candidate rappels down slope while others practice rope techniques during Phase 4 field training exercise.

Officer candidates render first salute during commissioning ceremony marking completion of Officer Candidates School.

Phase I: In-Processing

Core values are introduced, gear and uniform are provided, and training platoon is assigned. Medical and administrative processing is completed.

Phase II: Transition

Combat conditioning, close order drill, and Marine culture and leadership indoctrination. Academic instruction starts, and daily evaluation of candidates begins.

Phase III: Adaptation

Leadership billet holder responsibility, peer leading, land navigation, and basic tactics instruction. Accountability and teamwork are emphasized.

Phase IV: Decision-Making & Execution

Leadership traits and principles, tactics instruction, and problem-solving evaluation through events such as the Small Unit Leadership Evaluation (SULE).

Phase V: Out-Processing

Commissioning and orientation of future duties, The Basic School preparation, climax of esprit de corps.

From Proving Ground to Officer—What Comes After OCS

Those who succeed at OCS are commissioned as Second Lieutenants and have proven they have what it takes to be Marine Officers.

Officers then report to The Basic School (TBS)—a rigorous six-month program where they master the skills and decision-making needed to lead Marines.

More About TBS

Current Officer Candidates

If you are already an Officer Candidate seeking pre-ship preparation materials, such as the 60-day letter, please visit the candidates information page and select the tab for "Pre-Ship Preparation."

Recruiter in dress uniform speaks with prospective recruits at recruiting station beneath Eagle Globe and Anchor emblem.

Have Questions About OCS?

If you have questions about OCS, the commissioning process, or what it takes to lead Marines, a Marine Officer Selection Officer (OSO) is here to help.

Contact an OSO

FAQ

Commissioning in the Marine Corps is the formal process by which an individual receives an official appointment as a Marine Corps Officer. There are several ways to seek a commission, including Platoon Leaders Class, Officer Candidate Course, NROTC, the Naval Academy, The Citadel, and enlisted-to-officer programs. Please see Process to Commission as a Marine Corps Officer for more information.

Before beginning Marine Officer Candidates School, your Officer Selection Officer will guide your physical training regimen and prepare you for the challenge of becoming a Marine Corps Officer.