Infantry Officer

You are the rifle platoon commander. Forty-plus Marines, a platoon sergeant who has been doing this since before you commissioned, and a company commander whose FitRep on you is the document that decides whether this career continues. Learn the platoon. Do not try to out-Marine the SFC standing next to you.

You commission through OCS at Quantico or arrive via NROTC / the Naval Academy, then spend six months at TBS (The Basic School) where the Marine Corps decides whether you are actually an officer before it lets you pick an MOS. After IOC — the Infantry Officer Course at Quantico, roughly thirteen weeks, significant selection attrition, and the first moment the Corps formally tests whether you belong in the infantry — you arrive at 1st Marine Division at Pendleton, 2d Marine Division at Lejeune, or 3d Marine Division in Okinawa or Hawaii with orders to a rifle battalion and a billet as a rifle platoon commander. Your week is troop-leading procedures, the platoon scheme of maneuver for the next field op, FitRep counseling on your platoon sergeant and squad leaders, the company training meeting, range packets, and the BUB brief to the company commander that you will deliver, be corrected on, and deliver again. You will sign for sensitive items you cannot afford to lose, write a training plan that survives contact with the S-3 calendar, and spend more time in the company office and on administrative paperwork than IOC implied. The platoon sergeant runs the squad room; you run the planning, the resourcing, and the command — and you protect the platoon's time from the battalion taskings that do not belong on their calendar.

• 01Brief a clean five-paragraph order in front of the company commander — SMEAC, graphics readable, scheme of maneuver tight, supporting arms plan tied to the MCRP 3-10A.4 standard — without the CO having to rewrite it before the back-brief.
• 02Run troop-leading procedures from receipt of mission through the rehearsal step per MCDP 1-3 and MCRP 3-10A.4 — the rehearsal is the step lieutenants cut first and the battalion commander reads in your FitRep.
• 03Write clean FitReps on the platoon sergeant and the squad leaders per MCO 1610.7 — initial FitRep within the required window of assuming the billet, quarterly touchpoints, event-driven entries where warranted.
• 04Apply METT-T (mission, enemy, terrain, troops, time) in mission analysis at the platoon level — not a checklist, but the actual framework you plan from when the platoon commander's window is two hours.
• 05Build a platoon training plan that aligns with the company T&R requirements under NAVMC 3500.44, gets resourced through the S-3 long-range training calendar, and holds its shape through the battalion BUB.
• 06Read the platoon sergeant the way the platoon sergeant reads you — listen first, push back in private, never undercut in front of the squad leaders.

• —MCDP 1 — Warfighting (you will be quizzed on the ideas at TBS and IOC; the platoon sergeant will quote the philosophy back at you in the COC).
• —MCDP 1-3 — Tactics (the conceptual spine of every platoon attack, defense, and patrol order you will write).
• —MCRP 3-10A.4 — Marine Rifle Platoon (the manual the CO and platoon sergeant both quote from; own it before you arrive at IOC).
• —MCRP 3-10A.3 — Marine Rifle Squad (your squad leaders live in this; you need to be able to talk to them about it).
• —MCWP 3-01 — Offensive and Defensive Tactics for the MAGTF (platoon and company tactics in context of the larger scheme of maneuver).
• —MCO 1610.7 — Performance Evaluation System (the FitRep side — read the procedural requirements before your first rater-ratee touchpoint with the platoon sergeant).
• —MCO 1400.32 — Marine Corps Promotion Manual (understand the board mechanics and the FitRep relative-value system before your first cycle).

• —TBS graduate (The Basic School, Quantico, six months) — every Marine officer attends, and the class standing and small-group leader read travel to your gaining battalion before you do.
• —IOC graduate (Infantry Officer Course, Quantico, roughly thirteen weeks) — not all TBS graduates who request 0302 receive the designation; IOC is both training pipeline and selection screen. Pull current TECOM data for attrition figures rather than relying on rumored percentages.
• —PFT and CFT at the 1st-Class level per MCO 6100.13 — your platoon passes the same test; you do not get to fall out of anything they have to complete.
• —O-1 to O-2 is semi-automatic on the established timeline; O-2 to O-3 (Capt) is a board with historically high-but-not-guaranteed selection — pull current MMPB promotion board releases before drawing conclusions from rumored percentages.
• —Ranger Tab or equivalent special operations school is the differentiator between lieutenants the company commander recommends and lieutenants the company commander tolerates — not required on paper, but the read in a rifle battalion is real.

• —Trying to out-Marine the platoon sergeant. The staff sergeant running your platoon has spent years in the squad room; you had thirteen weeks at IOC. The platoon commander job is platoon-level planning and command, not squad-room SME — LTs who try to run the drills the platoon sergeant owns lose the platoon inside two months and the FitRep read reaches the battalion commander before the next cycle.
• —Cutting the rehearsal step. You will survive it once. The second time, the company commander watches the platoon fail a react-to-contact lane during an MCCRE evaluation and the FitRep bullets get rewritten.
• —Missing a sensitive item — weapon, NVG, radio, crypto — even once. As the lieutenant signing for the platoon's gear, one serial number unaccounted for is a command investigation with your name in the findings, and the battalion commander sees the outbrief.
• —Skipping or sloppy FitRep counseling. No initial FitRep counseling on the platoon sergeant on time, no quarterly touches with the squad leaders, no event-driven entry when something happened — and the company commander has nothing to defend you with when the Marine files a complaint and the file is blank.
• —Posting OPSEC-relevant content. Unit patch, field location, weapon serial, geotag on a deployment photo — the S2 runs sweeps and the PAO tracks it, and the battalion commander will know your name for the wrong reason.

The good rifle platoon commander is the lieutenant the company commander sends to brief the battalion commander without rehearsing the brief first. His platoon orders do not get rewritten by the CO. The platoon sergeant trusts him enough to push back honestly in private and then aligns publicly in front of the squad leaders. By the second FitRep cycle he has a clean property book, a platoon with the highest MCCRE lane scores in the company, and a senior rater profile that reads "top block, future company commander" — and the platoon does not love him. The platoon respects him, which is the only adjective that matters at this rank.

You are the company commander, or the field-grade officer whose company command tour is the fixed input every board from here to colonel uses. Company command is the KD — the Key Developmental tour that the Marine Corps uses to decide what kind of officer you actually are. The FitRep from that tour does not age out.

Your captain arc compresses staff utilization, career-broadening billets, and company command into roughly four to six years. After post-LT staff utilization — battalion S-3 air, BN S-1, BN adjutant, or regimental staff — you move through company XO (the proving ground before command) and then into company command: a rifle company (180+ Marines, four platoons, the CO authority under MCO 1610.7 and the UCMJ), a weapons company, or an HHC. As company commander you own the training plan, the property book, the FitRep cycle on six to eight officers and senior SNCOs, the UCMJ authority at the company grade, and the boundary between what the battalion commander needs and what the company can actually deliver. A CTC-equivalent workup — ITX at Twentynine Palms (MCAGCC), a combined arms exercise, pre-deployment training — defines your command tour's reputation before you hand the colors. Post-command you move into a senior captain billet (BN S-3, BN XO, regimental staff) or into the Expeditionary Warfare School (EWS) pipeline. As a major you are on staff — BN S-3, BN XO, regimental staff plans, or a joint billet — and the institutional read of your captain years is now a fixed input the promotion boards cannot un-see. The Maj board is the first genuinely competitive selection; the LtCol board is the major career gate. MMPB manages your assignment; your FitRep relative-value ranking among peers is everything.

• 01Write and brief a company OPORD inside the battalion scheme of maneuver per MCRP 3-10A.5 / MCRP 3-10A.6 — supporting arms integrated with the FSC, sustainment plan defensible, command-and-signal annex the platoon commanders can execute without clarification.
• 02Run a company through a combined arms exercise, ITX at Twentynine Palms, or pre-deployment workup as the commanding officer — the O/C/T or evaluator writing the AAR is a major or senior captain whose read travels back to your reporting chain.
• 03Manage company-level UCMJ — counseling, non-judicial punishment authority at the company grade, separation action initiation, coordination with the SJA — documented, defensible, and within the procedural requirements the JAG has already briefed you on.
• 04Sign for the company property book and survive a change-of-command inventory — the missing serial number the incoming CO finds in the inventory becomes a financial liability investigation with your name on the outgoing side.
• 05Write FitReps on six to eight rated officers and senior SNCOs per cycle per MCO 1610.7 — the relative-value ranking you assign determines which of your lieutenants gets the next KD slate and which one does not.
• 06Translate the battalion commander's intent two echelons down without losing it in the translation — as company commander, the regiment's intent has to live in the platoon commanders' OPORDs without you rewriting them for them.

• —MCDP 1 — Warfighting; MCDP 1-3 — Tactics (the conceptual foundation you teach your lieutenants from, not consume yourself).
• —MCRP 3-10A.5 / MCRP 3-10A.6 — Marine Rifle Company (own this cover to cover; the battalion commander and the regimental staff quote from it).
• —MCWP 3-01 — Offensive and Defensive Tactics for the MAGTF (the company and battalion-level tactical manual for every combined arms problem you plan).
• —MCO 1610.7 — Performance Evaluation System (the FitRep mechanics you now write against for six to eight rated officers; the relative-value ranking system is the lever; read the procedural requirements before your first reporting cycle as a CO).
• —MCO 1400.32 — Marine Corps Promotion Manual (Maj board mechanics, IPZ / BZ / AZ math, FitRep relative-value weighting — understand this before your company command OER cycle).
• —MCO 1540.8 series — Officer Professional Military Education; EWS and Command and Staff College catalog (the PME gates your LtCol board reads).
• —JP 3-09 — Joint Fire Support; JP 3-0 — Joint Operations (the joint context your BN S-3 and regimental staff billets require you to operate in).

• —Company command tour — 18-24 months, slated by the battalion commander and confirmed through MMPB. The single FitRep the Maj board and LtCol board care about with the same intensity that the platoon commander FitRep mattered at the LT tier. One weak RV (relative-value) ranking in the command tour compresses the board read in ways the rater's narrative cannot recover.
• —FitRep relative-value ranking above the peer group average in the battalion during command — the PRO/CON recommendation from the battalion commander is the most-read field on the Maj board.
• —ITX / combined arms exercise / pre-deployment workup as company commander — the most-observed performance window of the captain career to date; the regimental commander and the MAGTF commanding general see the AAR.
• —Expeditionary Warfare School (EWS) or Command and Staff College (C&SC) resident selection — the PME credential the LtCol board reads as proof the institution believes in the officer's potential.
• —Maj board at the IPZ window — the first genuinely competitive selection in the Marine officer career. Pull the current MMPB promotion board release for the actual FY selection rate; do not rely on rumored percentages from previous cycles.
• —B-billet or career-broadening tour between KD tours (recruiting duty, NROTC instructor, TBS or IOC instructor cadre, joint billet) — named in the FitRep and visible to the LtCol board as breadth of contribution.

• —Coasting through the staff tour between LT KD and company command. The battalion S-3 and the BN XO read your staff product before they brief the battalion commander, and the command slate is a small conversation between the BN CDR, the regimental commander, and MMPB — LTs who arrived strong and then drifted on staff are the captains who lose the command slot.
• —Losing the company command FitRep on a recoverable problem. A command investigation under your command, a lost sensitive item, a range incident that resulted in a battalion-level inquiry, a substantiated IG complaint — these do not kill the career immediately, but they materially compress the Maj board read and the LtCol board read in a small community where the reporting chain is the same four officers for six years.
• —Mishandling UCMJ at the company level. Skipping the SJA consult, issuing non-judicial punishment a Marine successfully appeals, or carrying a separation packet the battalion commander has to fix on your behalf — the BN CDR remembers which captains needed adult supervision on their legal actions.
• —Failing the change-of-command inventory. Property book gaps trigger a financial liability investigation; the battalion commander signs the outgoing documents and the FitRep comment is permanent.
• —Ignoring the FitRep relative-value conversation with the battalion commander. The PRO/CON recommendation and the RV stack are the inputs the Maj board actually reads — captains who do not understand how the relative-value ranking works end up in the bottom tier of a peer group they outperformed in the field.
• —Arriving at the BN S-3 or BN XO billet post-command without treating it as seriously as command. The regimental commander is reading the staff product; the post-command billet is the FitRep that determines EWS selection and the LtCol board signal.

The good company commander runs a company the battalion commander is willing to send to the worst combined arms exercise in the workup because they will not embarrass anyone in the AAR. The property book reconciles cleanly. The Article 134 packets are SJA-defensible. The four platoon commanders inside his company are reading FitReps the senior rater can profile honestly — and at least one of them is on the short list for a company command slate inside two years. The good senior captain post-command is the BN S-3 whose staff product the battalion commander briefs with, not at — the lieutenant colonel reads the OPORD annex once and signs. The good just-pinned major is the officer whose name the regimental commander already mentioned to the MMPB assignment monitor before the EWS selection board sat, and whose LtCol board cycle arrives as confirmation of what the battalion already knew.