Each military branch has 10 officers' grades (O-1 through O-10). The higher the number is, the more advanced a person's rank. The various branches of the military have somewhat different criteria for promoting individuals; in general, promotions depend on factors such as the number of years served, demonstrated abilities, advanced training, recommendations, and scores on written exams. Promotions become more and more competitive as people advance in rank. Some officers can expect to reach lieutenant colonel or commander (O-5). Outstanding individuals may be able to advance beyond these levels.
- Aeronautical and Aerospace Technicians
- Aerospace Engineers
- Architects
- Avionics Engineers
- Avionics Technicians
- Biosecurity Monitors
- Bodyguards
- Chemical Technicians
- Chemists
- Computer Network Administrators
- Computer Programmers
- Computer Systems Programmer/Analysts
- Cryptographic Technicians
- Drone Pilots
- Electronics Engineering Technicians
- Engineering Technicians
- Engineers
- Environmental Engineers
- Flight Instructors
- Fluid Power Technicians
- Futurists
- Gunsmiths
- Hypersonics Engineers
- Hypersonics Technicians
- Intelligence Officers
- Internet Security Specialists
- Interpreters
- Laboratory Testing Technicians
- Laser Technicians
- Manufacturing Supervisors
- Materials Engineers
- Mechanical Engineers
- Meteorologists
- Military Pilots
- Military Police
- Military Recruiters
- Military Workers, Enlisted
- Non-Destructive Testing Specialists
- Optical Engineers
- Physicists
- Pilots
- Quality Control Engineers
- Quality Control Technicians
- Radiation Protection Technicians
- Robotics Engineers
- Robotics Technicians
- Security Consultants
- Security Guards
- Space Pilots
- Space Systems Operators
- Translators