Career Comparisons
Two Marine MOS can look almost identical from the outside and still lead to very different four-year contracts. These side-by-side comparisons break down the enlisted jobs that recruits most often weigh against each other, so the choice is clear before you sit down with a recruiter.
Every comparison covers the same decision points: the core role, the ASVAB line-score gate, the training pipeline, the daily work, and who each job actually fits. The single factor that opens or closes most of these doors is your ASVAB score, so build it early with the ASVAB study guide while you weigh the options.
Infantry (03)
The 03 field is the largest enlisted community, and the choices inside it come down to weapon, mission, and screening.
- 0311 Rifleman vs 0331 Machine Gunner: rifle and maneuver versus crew-served weapons.
- 0321 Reconnaissance Marine vs 0311 Rifleman: small-team reconnaissance versus line infantry.
- 0311 Rifleman vs 0341 Mortarman: direct fire versus indirect mortars.
- 0321 Reconnaissance Marine vs 0313 LAR Marine: foot and amphibious recon versus light-armored reconnaissance.
Intelligence (02)
These two turn on what you collect and how you enter the field.
- 0231 Intelligence Specialist vs 0211 CI/HUMINT Specialist: all-source analysis versus counterintelligence and human collection.
- 0231 Intelligence Specialist vs 0241 Imagery Intelligence Specialist: all-source analysis versus imagery and GEOINT.
Signals, Cyber, and Communications (06, 17, 26)
The technical fields split on the work surface: networks, servers, signals, or cyber effects.
- 1721 Cyberspace Warfare Operator vs 2621 COMINT/EW Operator: offensive cyber versus signals intelligence and electronic warfare.
- 0631 Network Administrator vs 0671 Data Systems Administrator: network operations versus server and data systems.
Combat Support and Law Enforcement (08, 13, 23, 58)
These pairs separate by mission inside a shared field.
- 0811 Field Artillery Cannoneer vs 0861 Fire Support Marine: the gun line versus fire-support coordination.
- 1371 Combat Engineer vs 1345 Engineer Equipment Operator: combat engineering versus heavy equipment.
- 2311 Ammunition Technician vs 2336 EOD Technician: ammunition management versus explosive ordnance disposal.
- 5811 Military Police vs 5821 CID Criminal Investigator: patrol and law enforcement versus criminal investigation.
Start with your ASVAB
Most of these comparisons turn on a single ASVAB line score. Build that score first with the ASVAB study guide, then talk with a Marine Corps recruiter about current contract availability. To browse every topic, return to the Marine Corps guides.