The U.S. Marine Corps Marine Littoral Regiment (MLR)

The U.S. Marine Corps Marine Littoral Regiment (MLR)

The U.S. Marine Corps Marine Littoral Regiment (MLR)

Updated November 18, 2025 (IF12200)

Background

In March 2020, the U.S. Marine Corps (USMC) announced a major force design initiative planned to occur over 10 years originally referred to as "Force Design 2030" which is now known as "Force Design." Under Force Design, the Marines are redesigning forces to place a stronger emphasis on naval expeditionary warfare. As part of the redesign, the Marines originally planned to establish at least three Marine Littoral Regiments (MLRs) organized, trained, and equipped to accomplish a number of missions within contested maritime spaces.

MLR Missions

According to the Marines, the MLR is to be capable of the following missions:

Conduct Expeditionary Advanced Base Operations (EABO), a form of expeditionary warfare involving the employment of naval expeditionary forces. Selected Marine and Navy forces are to be arrayed in a series of austere, temporary locations ashore within a contested or potentially contested maritime area to conduct sea denial and control and fleet sustainment operations.

Conduct strike operations with a variety of systems.

Coordinate air and missile defense operations.

Support maritime domain awareness.

Support naval surface warfare operations.

Support information operations.

The MLR's Operational Environment

The Commandant of the Marine Corps' May 2022 Force Design 2030 Annual Update stated,

The security environment is characterized by proliferation of sophisticated sensors and precision weapons coupled with growing strategic competition. Potential adversaries employ systems and tactics to hold the fleet and Joint Force at arm's length, allowing them to employ a strategy that uses contested areas as a shield behind which they can apply a range of coercive measures against our allies and partners.

Operating in this environment, MLRs are intended to serve as what the Marines call a "Stand-In Force (SIF)," designed to help the fleet and joint force win the reconnaissance and counter reconnaissance battle within a contested area at the leading edge of a maritime defense-in-depth.

MLR Employment

According to a May 25, 2022, Marine Corps Association article "Missions, MAGTFs, Force Design & Change," by Colonel Michael R. Kennedy, USMC (Retired), MLRs are intended to

Deploy to islands, coastlines, and observation posts along chokepoints where their networked sensors and weapons can surveil the air and surface (and, potentially subsurface) waterways. The MLR's purpose will be to observe and prevent any "grey zone" activities that lead to fait accompli actions.

MLR Organizational Structure

Figure 1. Generic MLR

Source: Marine Corps Information Paper provided to CRS, April 3, 2025

Notes: H&S = Headquarters and Services; GBAB = Ground Based Air Defense.

As currently envisioned, the MLR is to consist of approximately 1,800 to 2,000 Sailors and Marines composed of four elements:

Command Element. A regimental headquarters with enhanced signals and human intelligence, reconnaissance, communications, logistics planning, civil affairs, cyber, and information operations capabilities.

Littoral Combat Team consisting of an infantry battalion and an anti-ship missile battery. The Littoral Combat Team is to provide the basis for multiple reinforced platoon-sized expeditionary advanced base sites capable of conducting a variety of missions.

Littoral Anti-Air Battalion designed to conduct air defense, air surveillance and early warning, air control, and forward rearming and refueling operations.

Littoral Logistics Battalion designed to resupply expeditionary advanced base sites, manage cache sites, and connect with higher-level logistics providers. The Littoral Logistics Battalion is also to provide limited purchasing authority, medical support, ammunition and fuel distribution, and field maintenance.

Selected MLR Systems

In order to accomplish the wide range of MLR missions, the Marines and Navy are pursuing a number of essential systems including, but not limited to, the following:

Navy-Marine Corps Expeditionary Ship Interdiction System (NMESIS)

NMESIS consists of the Naval Strike Missile mounted on the Joint Light Tactical Vehicle (JLTV). According to the Commandant's 2025 Force Design Update, the Marines fielded the first six NMESIS launchers to 3rd MLR in 2023 and continue to build capacity toward 18 launchers per medium range missile system launcher (MMSL) battery, which is to be fully realized in FY2033.

Marine Air Defense Integrated System (MADIS)

According to the Marines,

MADIS is a short-range, surface-to-air system that enables [MLR] Low Altitude Air Defense Battalions to deter and neutralize unmanned aircraft systems and fixed wing/rotary wing aircraft. Mounted aboard two JLTVs, MADIS has an organic radar and tracking system, a 30 mm cannon, and Stinger anti-aircraft missiles.

According to the Commandant's 2025 Force Design Update, the Marines have fielded the first 20 systems across the force.

Ground/Air Task Oriented Radar (G/ATOR)

According to the Marines,

G/ATOR is a three-dimensional, expeditionary, short/medium-range multirole radar capable of detecting low-observable, low-radar-cross-section targets such as rockets, artillery, mortars, cruise missiles, and manned and unmanned aerial systems.

According to the Commandant's 2025 Force Design Update, by the end of FY2025, nearly 60% of planned G/ATOR systems are to be fielded to the fleet.

MLR Establishment

On March 3, 2022, the Marines redesignated the 3rd Marine Regiment as the 3rd MLR at Marine Corps Base Hawaii. The 3rd MLR is expected to achieve FOC in FY2025. Reportedly, the 12th Marine Artillery Regiment stationed in Okinawa was to be reorganized into the 12th MLR by 2025. On December 5, 2024, the 12th Littoral Anti-Air Battalion was activated at Camp Hansen Okinawa, Japan. Reportedly, on January 10, 2025, the 1st Battalion, 4th Marines held a redesignation ceremony at Camp Pendleton, California, and are to be incorporated into the 12th MLR, which is to be part of the 3rd Marine Division, III Marine Expeditionary Force (MEF). The Marines also reportedly originally planned to transfer the 4th Marine Regiment from Okinawa to Guam, where it was scheduled to be reorganized into the 4th MLR in 2027.

Marine Corps Decision Not to Establish a Third MLR

The Commandant's 2025 Force Design Update states that the Marines will not reorganize the 4th Marine Regiment into the 4th MLR as originally planned, explaining that

[the] 4th Marine Regiment will be retained in III MEF as a reinforced Marine Infantry Regiment, preserving its core mission while preparing to respond to potential crisis and conflict. We determined through the Campaign of Learning that two MLRs and one reinforced Marine Infantry Regiment in III MEF is the optimal force composition to meet III MEF's missions and objectives. The Marine Corps will provide previously programmed MLR-associated equipment and personnel to III MEF to be task organized in support of the commander's objectives.

Potential Issue for Congress

A potential issue for Congress could include the following:

Status of the Navy Medium Landing Ship (LSM)

According to the Marines,

The LSM is central to providing mobility for fires, sensors, command and control, and sustainment across contested littorals. We are pursuing this program through a three-phased approach. First, we are filling today's gap with interim solutions under the Littoral Maneuver Bridging Strategy. Second, we are procuring LSM Block 1, a proven non-developmental vessel, to achieve initial operational capability. Third, we will procure LSM Block Next, a fully mature, optimized solution that incorporates advanced technologies. Working aggressively with the Navy, we are moving to field this capability as soon as possible.

Reportedly, the Navy had planned to acquire from 18 to 35 ships to support three MLRs, with the Navy's FY2026 budget request calling for $1.96 billion for the procurement of an initial nine LSMs. The Navy reportedly planned to acquire an original LSM design, but the "plan was abandoned in late 2024 when industry bids far exceeded the allocated budget." Reportedly, the Navy is "now pursuing a revised acquisition strategy based on the accelerated procurement of a commercial/non-developmental item (CNDI) design."

Given the Marines' LSM requirement and the Navy's decision to adopt a new acquisition approach, Congress might wish to further examine the potential issues associated with this decision and how it affects the MLR's near-term operational effectiveness. The Marines' decision to forgo a third MLR could also reduce the overall LSM requirement, potentially reducing program funding requirements and possibly expediting acquisition.

Additional Reading

CRS Report R47614, U.S. Marine Corps Force Design Initiative: Background and Issues for Congress, by Andrew Feickert