Headquarters Marine Corps released detailed implementation guidance this week for the Mexican Border Defense Medal, opening the award to Marines who have supported U.S. Customs and Border Protection (CBP) operations along the border with Mexico since January 2025.
MARADMIN 233/26, dated May 20, spells out eligibility rules, documentation requirements, and how the new medal interacts with the Armed Forces Service Medal that previously covered this service. The qualifying window remains open-ended until a termination date is announced.
This builds directly on earlier recognition for the same type of mission. In 2019, the Defense Department authorized the Armed Forces Service Medal (AFSM) for troops providing support to CBP.
Who Qualifies
Marines are eligible if they were permanently assigned, attached, or detailed to a unit that deployed for a designated Department of War operation supporting CBP and served at least 30 days (consecutive or cumulative) inside the area of eligibility.
The area includes U.S. land within 100 nautical miles of the international border with Mexico in Texas (explicitly including San Antonio), New Mexico, Arizona, and California, plus adjacent U.S. waters out to 24 nautical miles. The 30-day rule gives flexibility for Marines on shorter temporary additional duty or multiple rotations that add up over time.
The medal applies to the Total Force. Only one award is authorized per individual, regardless of how many qualifying deployments a Marine completes. No subsequent award devices are authorized.
Revival of 1918 Award
The Mexican Border Defense Medal revives the design of the Mexican Border Service Medal, first struck in 1918. That earlier award recognized U.S. service members who served along the border during a period of cross-border raids and instability in northern Mexico following the 1916 Punitive Expedition.
The bronze medal features a sheathed Roman sword hanging on a tablet inscribed “For Service on the Mexican Border.” The reverse carries the U.S. Coat of Arms inside a wreath that terminates in crossed rifles, sabers, and cannons, representing the infantry, cavalry, and artillery of the era. The green-and-golden-yellow ribbon stands for civic virtue in the defense of the nation.
By reintroducing this specific medal rather than continuing to use the broader Armed Forces Service Medal, the Department is giving this mission its own distinct place in the awards order of precedence, immediately after the Korea Defense Service Medal and before the AFSM.
How It Differs from the Armed Forces Service Medal
The AFSM remains a valid campaign and service medal for many other operations. For CBP support on the Mexican border, however, the Mexican Border Defense Medal is now the designated award after the August 13, 2025, cutoff date referenced in the MARADMIN.
Marines who already received the AFSM for qualifying service between January 20, 2025, and August 13, 2025, can request the new medal in its place. They may not keep both awards for the same period. The exchange is documented with a Page 11 entry. Any AFSM earned for CBP support before January 20, 2025, stays in the record and is not eligible for exchange.
No certificate or citation accompanies the Mexican Border Defense Medal.
Approval and Administrative Steps
Commanding officers who already have the authority to award the Navy and Marine Corps Achievement Medal can approve the Mexican Border Defense Medal.
Units verify service with deployment orders, TAD or PCS orders, muster rosters, or official command certification showing dates and location inside the area of eligibility. Local reporting units enter the award in the Marine Corps Total Force System using the appropriate code. Headquarters Marine Corps will issue follow-on instructions for retroactive record updates.
Marines who believe they qualify should route supporting documentation through their chain of command for verification and submission.
Marine units have continued to rotate through border support missions in recent years, including engineer elements reinforcing physical barriers and logistics Marines enabling sustained operations, as covered in prior Military.com reporting on Marine support to border operations.
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