The Service Rules That Implement the UCMJ: AR 27-10, JAGMAN, and AFI 51-201
On this page
- What this layer is and why it exists
- The three regulations at a glance
- Army: AR 27-10
- Navy and Marine Corps: the JAGMAN
- Air Force and Space Force: AFI/DAFI 51-201
- Where the services genuinely diverge
- Frequently asked questions
- If the UCMJ already applies to everyone, why are there separate service regulations at all?
- Is “Captain’s Mast” a different punishment from an “Article 15”?
- Why do the Navy and Marine Corps share one regulation?
- What is the difference between AFI 51-201 and DAFI 51-201?
- Do these regulations override the UCMJ or the Manual for Courts-Martial?
- Sources and Authorities
- Disclaimer
The Uniform Code of Military Justice and the Manual for Courts-Martial set one baseline for every armed service, yet a soldier, a sailor, a Marine, and an airman do not experience military justice through identical paperwork, identical officials, or even identical vocabulary. The reason is a layer of regulation that sits beneath the code and the Manual: each service issues its own military-justice regulation that fills in who does what, what the forms are called, and how a case actually moves on the ground. Knowing which regulation governs, and where the services diverge, is the kind of practical cross-walk that the code and the Manual themselves do not provide, because each of those documents is service-blind by design.
This discussion owns the service-implementation layer. The UCMJ and the Manual for Courts-Martial are treated here only as the law these regulations carry out; the focus is on the regulations and the differences among them, not on re-explaining the code.
What this layer is and why it exists
The UCMJ is the federal statute. The Manual for Courts-Martial is the President’s executive-order implementation of that statute, containing the Rules for Courts-Martial and the Military Rules of Evidence that apply uniformly. Neither, however, says which office in a given service maintains the records, what an Army “Article 15” form looks like versus an Air Force one, or how a Navy case is routed when it arises aboard a ship at sea. Those operational details belong to the services.
Each Secretary, acting through the service’s Judge Advocate General, issues a service regulation to supply them. These regulations cannot contradict the UCMJ or the Manual; they implement and amplify them. Where the higher law is silent or leaves a choice, the service regulation decides, and where the higher law commands, the regulation tracks it. The result is a consistent legal core with service-specific plumbing, and the plumbing is what differs.
The three regulations at a glance
| Army: AR 27-10 | Navy and Marine Corps: JAGMAN (JAGINST 5800.7) | Air Force and Space Force: AFI/DAFI 51-201 | |
|---|---|---|---|
| Full title | Army Regulation 27-10, "Legal Services: Military Justice" | Manual of the Judge Advocate General (JAGMAN), JAG Instruction 5800.7 series | "Administration of Military Justice" |
| Issued by | Secretary of the Army / The Judge Advocate General | Secretary of the Navy / Navy Judge Advocate General | Department of the Air Force / The Judge Advocate General |
| Services covered | Army (Active, Reserve, and, when in federal service, National Guard) | Navy and Marine Corps (the term "Navy" in the Manual includes the Marine Corps unless context differs) | Air Force and Space Force |
| What it governs | Nonjudicial punishment procedures, court-martial administration, military-justice records, and the trial and defense organizations within the Army | Administrative investigations, nonjudicial punishment, court-martial administration, and JAG-office procedures across two services | Military-justice administration, nonjudicial punishment, and court-martial processing; it also absorbed the former separate judiciary regulation |
| Term for nonjudicial punishment | "Article 15" | Navy: "Captain's Mast" (or Admiral's Mast). Marine Corps: "Office Hours" | "Article 15" |
| Notable structural trait | Detailed, chapter-based, with a dedicated chapter for Reserve-component justice | Single manual deliberately spanning two services at once | Centralized, with strong higher-headquarters oversight of the process |
The single most useful thing this table captures is that the same UCMJ mechanism wears three or four different names depending on the uniform, and that one of these regulations is doing double duty for two services at once. Those are exactly the facts the primary code conceals.
Army: AR 27-10
The Army’s military-justice regulation is Army Regulation 27-10, titled “Legal Services: Military Justice.” The current edition became effective in early 2025 and implements the 2024 Manual for Courts-Martial, which itself reflects recent statutory reforms. AR 27-10 is the most chapter-by-chapter of the three regulations: it lays out nonjudicial punishment in detail, prescribes how courts-martial are administered and how records are kept, governs the Army’s trial-counsel and defense-counsel organizations, and devotes a dedicated chapter to military justice within the Reserve components, where command and jurisdictional questions are more complicated.
In Army usage, nonjudicial punishment is simply “Article 15,” named after the UCMJ article that authorizes it. A commander who imposes it is using the regulation’s procedures to discipline minor offenses without a court-martial, and the regulation prescribes the notification, the right to consult counsel, the right to demand trial by court-martial instead, and the appeal route. The vocabulary is plain and statute-derived, with none of the maritime tradition the sea services carry.
Navy and Marine Corps: the JAGMAN
The Navy and Marine Corps share a single document, the Manual of the Judge Advocate General, universally called the JAGMAN and issued as a JAG Instruction in the 5800.7 series. It is unusual precisely because it is one regulation governing two services at once: within it, “Navy” generally includes the Marine Corps unless the context says otherwise. Beyond court-martial administration and nonjudicial punishment, the JAGMAN is also the authority for the sea services’ administrative investigations, the fact-finding inquiries that often precede any disciplinary decision.
The naval tradition shows most clearly in the vocabulary. In the Navy, nonjudicial punishment is “Captain’s Mast,” the name surviving from the era when a ship’s captain heard disciplinary matters at the mast; when the imposing officer is a flag officer it becomes “Admiral’s Mast.” In the Marine Corps the very same proceeding is called “Office Hours.” Both are the identical Article 15 mechanism the Army calls “Article 15,” governed by the same UCMJ article and the same Part V of the Manual, just dressed in different service language. The JAGMAN also accounts for circumstances the land services rarely face, such as discipline arising aboard a deployed vessel, which is one practical reason a single combined manual made sense for the two sea services.
Air Force and Space Force: AFI/DAFI 51-201
The Air Force regulation is “Administration of Military Justice,” long known as AFI 51-201 and now also published under the Department of the Air Force designation DAFI 51-201; the two labels refer to the same instrument, a product of a department-wide renaming convention. The current edition dates to early 2024, implements the Department of the Air Force’s military-justice policy directive and the current Manual for Courts-Martial amendments, and notably consolidated the former separate judiciary instruction into itself. Because the Space Force is part of the Department of the Air Force, this regulation reaches both services.
In Air Force and Space Force usage, nonjudicial punishment is “Article 15,” the same plain term the Army uses, not “Mast” or “Office Hours.” The instruction is comparatively centralized, with meaningful oversight of the military-justice process by higher headquarters, a structural emphasis that distinguishes it from the Army’s more decentralized, chapter-driven approach.
Where the services genuinely diverge
Three differences matter most in practice, and they are the ones the UCMJ and Manual do not surface.
First, the name of nonjudicial punishment. Army: “Article 15.” Air Force and Space Force: “Article 15.” Navy: “Captain’s Mast” or “Admiral’s Mast.” Marine Corps: “Office Hours.” Four labels, one mechanism. The label signals the service culture, not a difference in the underlying authority, which is Article 15 of the UCMJ in every case.
Second, the breadth of the document. The JAGMAN covers two services in one manual and folds in administrative investigations; AR 27-10 is Army-only but exhaustively detailed, down to a separate Reserve-component chapter; AFI/DAFI 51-201 is Air Force and Space Force and leans toward centralized oversight, having pulled the judiciary rules into a single instruction. Different drafting philosophies for the same statutory job.
Third, the convening-authority architecture is described in each regulation but rests on a common UCMJ framework. Every service recognizes three levels of authority to convene the three types of court-martial: a summary court-martial convening authority, a special court-martial convening authority, and a general court-martial convening authority, ascending with the seriousness of the case. The regulations specify which commanders in that service hold each level and how a case is routed and reviewed. The detailed treatment of who the convening authority is, and how recent reform stripped certain charging decisions out of the chain of command entirely, belongs to the dedicated discussion of convening authority and is not repeated here.
A worked illustration ties it together. Suppose a junior enlisted member is accused of a minor offense and the commander decides to handle it short of a court-martial. In the Army or the Air Force the paperwork and the proceeding are an “Article 15.” Aboard a Navy command the same proceeding is a “Captain’s Mast.” In a Marine unit it is “Office Hours.” The member’s core rights are the same in all of them, because they flow from the UCMJ and the Manual: notice of the alleged offense, the opportunity to consult counsel, the right to refuse nonjudicial punishment and demand trial by court-martial instead (with a narrow exception for those attached to or embarked on a vessel), and a right of appeal. The service regulation supplies the form numbers, the routing, and the name on the door; the rights underneath come from the code.
Frequently asked questions
If the UCMJ already applies to everyone, why are there separate service regulations at all?
Because the UCMJ and the Manual for Courts-Martial set the law but deliberately leave operational details to the services: which office keeps the records, what the forms are called, how cases are routed, and which commanders hold which authority. Each service fills those gaps with its own regulation that implements and amplifies the higher law without contradicting it.
Is “Captain’s Mast” a different punishment from an “Article 15”?
No. They are the same nonjudicial-punishment mechanism under Article 15 of the UCMJ. “Captain’s Mast” is the Navy’s name for it, “Office Hours” is the Marine Corps’s name, and “Article 15” is the term the Army, Air Force, and Space Force use. The label reflects service tradition, not a different legal authority.
Why do the Navy and Marine Corps share one regulation?
The Department of the Navy includes both the Navy and the Marine Corps, and a single Manual of the Judge Advocate General, the JAGMAN, governs military justice for both. Within it, references to “Navy” generally include the Marine Corps unless the context indicates otherwise, which is why one document can serve two services.
What is the difference between AFI 51-201 and DAFI 51-201?
They are the same instruction. The Department of the Air Force adopted a “DAFI” naming convention for instructions that apply across both the Air Force and the Space Force, so the regulation appears under both the older “AFI” label and the newer “DAFI” label. The substance is identical.
Do these regulations override the UCMJ or the Manual for Courts-Martial?
No. Service regulations are subordinate. They implement and add detail to the UCMJ and the Manual, and they cannot lawfully contradict them. Where the higher law commands a result, the regulation follows it; where the higher law is silent, the regulation supplies the service-specific procedure.
Sources and Authorities
- Army Regulation 27-10, “Legal Services: Military Justice,” current edition effective 2025, implementing the Manual for Courts-Martial, United States (2024). U.S. Army Publishing Directorate.
- Manual of the Judge Advocate General (JAGMAN), JAG Instruction 5800.7 series, Department of the Navy, Office of the Judge Advocate General (governing the Navy and Marine Corps).
- Air Force Instruction / Department of the Air Force Instruction 51-201, “Administration of Military Justice,” current edition dated 2024, implementing Department of the Air Force military-justice policy and the current Manual for Courts-Martial amendments.
- Uniform Code of Military Justice, Article 15 (10 U.S.C. 815), nonjudicial punishment; Manual for Courts-Martial, Part V (nonjudicial punishment procedures).
Disclaimer
This article explains how the individual armed services implement the Uniform Code of Military Justice through their own regulations, and how those regulations differ in terminology and structure. Service regulations are amended periodically; the editions and effective dates described here reflect publicly available current versions and may change. This is general educational information about how the military-justice system is organized, not legal advice about any specific case or disciplinary action, and it does not create any attorney-client relationship.