Marine Corps MOS · Support

8999 Sergeant Major-First Sergeant

Current service use not established

This code is listed in the directory. Inclusion alone does not confirm current service use.

Overview

A Sergeant Major or First Sergeant oversees matters affecting unit morale, welfare, discipline, mission success, and readiness while disseminating and enforcing Marine Corps and local policies, orders, and directives. This senior enlisted leader manages enlisted career human resource matters and maintains and develops the unit's total force.

Minimum clearance: Secret

Core Skills

  • Enlisted career human resources oversight
  • Command policy dissemination and enforcement
  • Personnel welfare and readiness oversight

Civilian Career Paths

Career associations are editorial assessments of the cited evidence, not an official crosswalk unless the evidence explicitly says so. O*NET supplies civilian occupation information, not proof of a military match. Related experience does not confer civilian qualifications. Tasks and tools below describe civilian work, not military training.

Human Resources Managers

Responsibility for enlisted career human resources, personnel welfare, discipline, and policy enforcement transfers directly to employee relations and HR oversight.

How to prepare: Complete a civilian employee-relations course covering disciplinary procedures and labor contracts to bridge military personnel policy and civilian HR practice.

What the civilian work involves
  • Serve as a link between management and employees by handling questions, interpreting and administering contracts and helping resolve work-related problems.
  • Plan, direct, supervise, and coordinate work activities of subordinates and staff relating to employment, compensation, labor relations, and employee relations.
  • Perform difficult staffing duties, including dealing with understaffing, refereeing disputes, firing employees, and administering disciplinary procedures.
Civilian tools and software (examples)
  • Microsoft Excel
  • Workday software

Notes & Sources

Evidence for this guidance (2 documents)
  1. NAVMC 1200.1L (FY26, in force): MOS 8999

    [1] MOS 8999 section "a. Summary"; cached text line 58477; NAVMC 1200.1L signed 2025-03-07, in force until 2026-10-01

    Supports: Enlisted career human resources oversight, Command policy dissemination and enforcement, Personnel welfare and readiness oversight, Human Resources Managers (O*NET 11-3121.00)

  2. O*NET: Human Resources Managers

    [2] O*NET 30.3 occupational data

    Supports: Human Resources Managers (O*NET 11-3121.00)

Defense contractor jobs for 8999

Predecessor codes

Historical codes with documented links to 8999. Each history page explains the change.

Descriptions may be summarized for clarity. Verify all information with your branch career counselor or official military documentation before making career decisions.

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