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MOS COMPARISON

5831 vs 5821

Correction and Detention Specialist (USMC) vs Criminal Investigator (USMC)

Intel

The Marine Corps promised both of these would "make you a leader." The methods range from "forging in fire" to "death by PowerPoint."

If both of these MOS codes had to write an honest shift report, the 5831's would read: the emotional weight of the job is real — you're confining fellow Marines, people who wore the same uniform, and the dynamic is uncomfortable by design. And the 5821's would read: federal law enforcement agencies — NCIS equivalents, FBI, DEA, ATF — recruit from military CID-equivalent investigators. Same form, different ink, completely different energy. The ratings below are from people who actually did these jobs. The blurb above is from us. Trust the ratings.

5831Marines
Correction and Detention Specialist
Overall ratingNo reviews yet
Do It Again
Civilian Pay
$72K
5821Marines
Criminal Investigator
Overall ratingNo reviews yet
Do It Again
Civilian Pay
$72K
Head to Head
5831
5821
Getting In
ASVAB Line Scores
GT 100MM 95
GT 100MM 95
Clearance
Secret
Pay Grade
Enlisted
Enlisted
Enlistment Bonus
Up to $8,000
Training
Training Length
8 wk
16 wk
Pipeline Type
Recruit Training
Training Location
Fort Leonard Wood, MO
Fort Leonard Wood, MO
Day-to-Day
Promotion Speed
Average
Deployment Tempo
Low
Career Field
Military Police and Corrections
Military Police and Corrections
After You Get Out
Civilian Median Pay
$72K
$72K
Top Civilian Career
Police and Sheriff's Patrol Officers
Police and Sheriff's Patrol Officers
Credentials Earned
4 certs

After the Uniform

The part the recruiter skips: what each job actually translates to once you're a civilian — and what it pays.

5831Correction and Detention Specialist
Civilian Median Pay
$72K/yr
What It Becomes on the Outside
Police and Sheriff's Patrol OfficersStrong
Job market: Faster than average (5%)
$72K
Correctional Officers and JailersStrong
Correctional Officers and JailersRelated
Job market: Declining (-6%)
$50K
Private Detectives and InvestigatorsRelated
Job market: Faster than average (6%)
$59K
Credentials You Walk Away With
Correctional specialist certificationDefensive tacticsUse of force certificationsRehabilitation program certifications
5821Criminal Investigator
Civilian Median Pay
$72K/yr
What It Becomes on the Outside
Police and Sheriff's Patrol OfficersStrong
Job market: Faster than average (5%)
$72K
Correctional Officers and JailersRelated
Job market: Declining (-6%)
$50K
Private Detectives and InvestigatorsRelated
Job market: Faster than average (6%)
$59K

Salary data from the U.S. Bureau of Labor Statistics Occupational Employment and Wage Statistics program. A guide, not a guarantee.

Recruiter vs. Reality

The pitch versus what people who actually did the job report back.

5831Correction and Detention Specialist
What the Recruiter Says

Correctional Specialists manage Marine Corps brigs and detention facilities with the highest standards of discipline and rehabilitation. You'll receive advanced corrections training, behavioral management expertise, and develop leadership skills that translate to careers in federal corrections, security management, and criminal justice.

What It's Actually Like

You are a Corrections Specialist, which means you run the brig, the Marine Corps' version of jail for Marines who made spectacularly poor decisions. Your daily population includes everything from the lance corporal who went UA for the fifth time to the serious offenders awaiting court-martial for crimes that would make the evening news. You maintain physical security of the facility, process inmates, conduct headcounts, manage behavioral observation, and enforce standards with the kind of military precision that civilian corrections officers find either impressive or insane. The emotional weight of the job is real — you're confining fellow Marines, people who wore the same uniform, and the dynamic is uncomfortable by design. Restraint techniques, defensive tactics, and use-of-force training are constant because brig populations are not cooperative by nature. Your brig counselor role means you also manage rehabilitation programs, coordinate legal visits, and maintain records that will be reviewed by JAG, the convening authority, and occasionally a congressional inquiry. The psychological toll of corrections work is well-documented and underappreciated. The good news: civilian corrections, federal Bureau of Prisons (BOP), U.S. Marshals Service, and state departments of corrections all actively recruit military corrections specialists. Your federal training certifications and experience with high-security populations translate to $45-70K corrections and law enforcement positions.

5821Criminal Investigator
What the Recruiter Says

You'll conduct criminal investigations — felony-level cases involving assault, fraud, drug trafficking, and the full range of serious offenses that occur in the military. Marine criminal investigators develop genuine law enforcement tradecraft: interviewing witnesses, managing evidence chains, writing investigative reports that support prosecution. Federal law enforcement agencies and civilian investigative units actively recruit investigators with this background.

What It's Actually Like

Military criminal investigation is real law enforcement work — the cases are genuine, the prosecutions are real, and the investigative skills transfer directly to civilian law enforcement. You'll handle cases that civilian departments would assign to their most experienced detectives, often with fewer resources and more command involvement than civilian investigators would tolerate. The chain of custody requirements, investigative report standards, and courtroom testimony experience are all legitimate law enforcement credentials. Federal law enforcement agencies — NCIS equivalents, FBI, DEA, ATF — recruit from military CID-equivalent investigators. Civilian police departments and private investigative firms value the background. The cases you work will test your judgment and your persistence in ways that shape your professional character.

The Real Life

Same dimensions, side by side. 5831 on the left, 5821 on the right.

Daily Life
5831

Managing the custody, control, and rehabilitation of military prisoners in Marine Corps brigs. Processing inmates, conducting cell inspections, managing prisoner movements, maintaining security protocols, and facilitating rehabilitation programs. Shift work is standard — 24/7 operations require nights, weekends, and holidays.

5821

Training / School
5831

Correctional specialist training covers corrections procedures, inmate management, use of force, defensive tactics, and rehabilitation programming. The training prepares you for the unique environment of managing military prisoners — service members who have committed UCMJ violations.

5821

Physical Demands
5831

Moderate to high. Corrections work requires physical fitness for restraint, self-defense, and emergency response. The mental demands — managing confined military prisoners — are significant.

5821

Where You'll Be Stationed
5831
Camp Pendleton (CA)Camp Lejeune (NC)Miramar (CA)Various Marine Corps brigs
5821
The Honest Truth
5831

Correctional specialists manage Marine Corps brigs — military jails. The recruiter will never mention this MOS. The reality: corrections work is demanding, stressful, and often thankless. You manage service members who have committed crimes, and the environment is inherently tense. Shift work is the norm, the facilities are few (limiting your duty station options), and the emotional toll is real. On the positive side: the civilian corrections industry is massive and always hiring, federal BOP positions pay well and offer good benefits, and the discipline and crisis management skills you develop are genuinely valuable. If you can handle the psychological demands, the career path is stable and the skills transfer directly. Just don't underestimate the mental health impact — seek support proactively.

5821

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