MOS 0621 Radio Operator sets up satellite communication

Marine Transmission System Operator (MOS 0621)

Regular and daily communication is crucial to the Marines under any circumstances, which is why Marine Transmission System Operators (MOS 0621) are so important.

During combat, accurate and dependable communication is even more essential.

Transmission System Operators who handle the operation and maintenance of communication equipment are necessary to ensure that essential information is communicated quickly and efficiently.

The Marine Corps MOS 0621 is a versatile specialty where Marines are assigned to a wide variety of units to ensure communication is possible for the integrity of the mission.

Transmission System Operators (MOS 0621) set up radio communication equipment so the unit can maintain contact with others.

This field in the Marines originally began in 1932 as a Pigeon and Flag Handler Platoon, although the field has evolved to include much more sophisticated technology.

Related Article4 Steps For Visiting A Marine Corps Recruiter Near You

Requirements and Qualifications for MOS 0621

MOS 0621 Radio Operator conducts a radio check

There are a few requirements to consider before becoming a Transmission System Operator.

In general, the basic requirements are the same for all Marines, including high school diplomas, citizenship, and physical requirements.

Marines who wish to be Transmission System Operators must complete the Basic Communications Course and the Transmissions System Operator Course.

Also, Transmission System Operators must pass a secret security clearance.

All members of the military take the ASVAB test to determine aptitude for specific vocations and to be a Transmission System Operator, your score for the Electronics section (EL) should be 105 or better.

Other requirements include the capability to communicate effectively and precisely, as well as the ability to solve problems quickly.

Transmission System Operators must also have normal color vision.

Also, preferring detail-orientated work and multi-tasking is essential.

MOS 0621 Training and Career Path

Training for MOS 0621 occurs in 29 Palms, California, after boot camp and combat training.

The training is at the Marine Corps Communication-Electronics School (MCCES), which is where the Marines train most of the communications specialties.

However, because class sizes are small, there is often a waiting period onsite to begin training, which lengthens the amount of time a Marine must wait before starting work in their specialty.

This waiting time is referred to as Marines Awaiting Training (MAT).

During this training, Marines learn tactical communications, electronics maintenance, air control, and anti-warfare operations.

The Tactical Communications Training School (TCTS) is where Transmission System Operators learn their skills.

As you move up in rank and gain experience, your next level of training is as a Transmission Supervisor.

Related ArticleMarine Corps MOS List and ASVAB Scores: Details Of All 123 Jobs

Working Conditions for a MOS 0621

A Transmission System Operator can find themselves working with a variety of units.

You might be attached to an engineer, headquarters, or communication unit.

Some in this MOS find themselves attached to an artillery or infantry unit, however.

A Transmission System Operator is not an infantryman, but when attached to these units, they may find themselves in combat handling the radios.

Pay and Benefits

As a Marine, you will enjoy competitive pay and benefits.

Basic pay is calculated by rank and the amount of time in service.

InsigniaPay GradeRankAbbreviation2023 Minimum Monthly Pay
E-1 +4 monthsPrivatePvt$1,917.60
E-2Private First ClassPFC$2,149.20
E-3Lance CorporalLCpl$2,259.90
E-6Staff SergeantSSgt$2,980.50
E-7Gunnery SergeantGySgt$3,3445.80
E-8Master SergeantMSgt$4,957.20
E-8First Sergeant1stSgt$4,957.20
E-9Master Gunnery SergeantMGySgt$6,055.50
E-9Sergeant MajorSgtMaj$6,055.50
E-9Sergeant Major Of The Marine CorpsSgtMaj$6,055.50

Also, the Marines have a housing allowance, healthcare coverage, subsidized food, retirement, as well as other benefits that add up to significant savings and add to your overall compensation package.

MOS 0621 Job Details

The duties of the MOS 0621 include maintaining and operating radios with different frequencies and creating contact with different stations or units.

Also, a Transmission System Operator will handle changing the frequency of radios and changing the codes that ensure information is transmitted safely.

Furthermore, it is vital Transmission System Operators maintain the equipment as well as the software.

MOS 0621 Radio Operator during communication exercise

Job Reviews

Reviews from those who currently serve in the Marines in this capacity note the training and work are often challenging.

Also, some service members discuss difficulties with deployments and incompatibility with some in leadership positions.

However, most discuss the positive feelings of being able to travel and the consistency the Marine offers.

Indeed review for MOS 0621 Indeed review for MOS 0621 Indeed review for MOS 0621

Related Article: 13 Pros And Cons Of Joining The Marines

Civilian Career Opportunities

Because of the security clearance necessary for this MOS, many Marines consider federal employment when leaving the military.

There are a few federal jobs that have a similar education and experience as the MOS 0621.

These include:

  • Intelligence
  • Cryptography
  • Information Technology Management
  • Radio Officer/Assistance Radio Officer

Those in federal jobs are well-compensated.

For instance, a Transmission System Operator might consider applying for a job as a Lead Intelligence Operations Specialist.

This position averages $126,495 per year. 

Another opportunity for a Transmission System Operator is a federal position as an IT Specialist.

IT Specialists can expect a salary range from $59,681 up to $185,829, depending on experience and responsibilities.

There are civilian opportunities, as well.

First-Line Supervisors of Mechanics, Installers, and Repairers

In this position, you can expect to supervise the activities of repairers, installers, and mechanics.

There is an expectation that this industry will grow by 5% over the next few years.

Ideally, candidates have up to five years of experience in this field.

The typical salary for this position averages $76,020 a year, according to the U.S. Bureau of Labor Statistics

Network and Computer Systems Administrators

A position as a Network and Computer Systems Administrator include handling the local area network (LAN) and the wide-area network (WAN), as well as the internet systems.

New job opportunities are expected to grow in this field, and you can expect a salary averaging $97,160.

Related ArticleArmy Radio Operator (MOS 25C): Career Details


The career as a Transmission System Operator in the Marines has evolved over the decades.

However, what has not changed is the need to communicate effectively and safely.

Transmission System Operators play an essential part in the Marine Corps, and they do their work in a variety of units, including infantry.

The training for MOS 0621 is in California, and Marines attend this advanced training after completing boot camp and combat training.

After training, Marine Transmission System Operators report to their assigned unit to perform their duties.

These duties include maintaining and operating radios and ensuring the information is transmitted securely and quickly.

The Marine Corps offers a competitive pay package between base pay and allowances for housing and other benefits.

As a civilian, former Marines might look into federal jobs due to the possession of secret security clearance.

However, there are jobs in the private sector, as well.


Jeff E.
MOS 0621

MOS 0621

4.6 out of 5 (25 Ratings)

Marine Transmission System Operators, or MOS 0621, is responsible for maintaining and operating radios with different frequencies, and creating contact with different stations or units.

Originally posted on 06/17/20

Affiliate Disclosure: This post may contain affiliate links. If you click and purchase, I may receive a small commission at no extra cost to you. I only recommend products I have personally vetted. Learn more.

Leave a Reply

Your email address will not be published. Required fields are marked *