8xxx Billet Designators / Marine Corps MOS Profile

8999 First Sergeant / Sergeant Major

First Sergeants and Sergeants Major are senior enlisted advisors responsible for discipline, welfare, readiness, standards, and enlisted leadership across commands.

Code / Pipeline8999
MOS NameFirst Sergeant / Sergeant Major
Category8xxx Billet Designators
Unit AssociationSenior Enlisted Leadership

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Marine Corps MOS Profile

Responsibilities and Pipeline

Primary Responsibilities

Advise commanders on enlisted readiness, discipline, morale, training, standards, and professional development.

Training Pipeline

Build credibility through progressive enlisted leadership and MOS proficiency.

Billet Progression

This MOS page summarizes the billet, training lane, progression path, and current command-profile matches.

Current Member Tracking

The Current Members section below is populated from command-record MOS data. When a chain of command changes MOS, this page is regenerated to keep the roster link accurate.

USMC Responsibilities

8999 First Sergeant / Sergeant Major is described here by practical Marine Corps duties, billet expectations, and training progression. This section avoids game-language so the page reads like a professional MOS reference.

  • Advise commanders on enlisted readiness, discipline, morale, training, standards, and professional development.
  • Supervise staff processes, unit routines, inspections, mentorship, and accountability of senior enlisted leaders.
  • Translate command intent into enforceable standards for companies, battalions, squadrons, or higher headquarters.
  • Protect institutional standards while coaching Marines through career progression and leadership challenges.

Training Pipeline

The pathway is shown at a broad public level. Exact prerequisites, screening, quotas, course names, and assignments can change by fiscal year, manpower requirement, medical qualification, command screening, and schoolhouse policy.

  1. Build credibility through progressive enlisted leadership and MOS proficiency.
  2. Serve in company, battalion, squadron, or higher command senior enlisted billets.
  3. Complete PME and billet-specific leadership development.
  4. Advise commanders and lead enlisted-force standards across training, discipline, readiness, and morale.

Billets And Skill Growth

  • Entry-level Marines focus on core tasks, equipment, field discipline, and reliable execution.
  • NCOs supervise small teams, enforce standards, plan rehearsals, and train junior Marines.
  • SNCOs and officers manage readiness, risk, training plans, inspections, reporting, and integration with adjacent staff sections.
  • Instructor and staff billets preserve standards, document lessons learned, and build repeatable training for the next rotation.

Chain of Command Matching Logic

Chain of command records can list a current MOS, prior record MOS, ADMOS, or specialty track. This page shows a member as a Current MOS when the MOS is the member’s active specialty and as Recorded Profile MOS / ADMOS when it appears in the member history.

Rank / Grade Requirements

Grade LaneSenior enlisted billet designator
Entry / Award Basis

First Sergeant / Sergeant Major MOS for senior enlisted Marines selected into the first sergeant/sergeant major path.

Typical Rank Use

First Sergeant and Sergeant Major grades only: E-8 and E-9.

Schoolhouse & Qualification Requirements

SchoolhouseSenior enlisted professional military education and First Sergeant / Sergeant Major assignment pipeline

Senior enlisted leader development centers on command climate, discipline, force readiness, mentorship, inspections, administration, and commander advisement.

Entry QualificationsScreening / Prerequisites

Requires selection to the senior enlisted program, time-in-service/time-in-grade requirements, PME, sustained performance, and command screening.

Associated SchoolsFollow-On Training
  • Senior enlisted PME
  • Command climate and legal/admin sustainment
  • Force preservation and readiness programs

Course titles, quotas, prerequisites, and sequence can change by fiscal year, manpower requirement, medical qualification, and current schoolhouse policy.

Current Members in this MOS

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