Unit Deployment Program 25.1

2nd Battalion, 23rd Marine Regiment

4th Marine Division

ABOUT

To reduce the number of unaccompanied tours and improve unit continuity, the Commandant of the Marine Corps (CMC) established UDP to provide for the deployment of units to the Western Pacific (WESTPAC) for periods of approximately six months. The initial program was a six-phased evolution that sequenced infantry battalions and aircraft squadrons/detachments into WESTPAC deployments, thus eliminating the 12-month permanent change of station assignments for personnel assigned to these units.

news / PHOTOS / VIDEOS

Activated Reserve Marines Conduct Live Fire MOUT during Korea Viper 25.4

U.S. Marine Corps Cpl. Issac Hurst, a mortarman with 2nd Battalion, 23rd Marines forward deployed with 4th Marine Regiment, 3d Marine Division as part of the Unit Deployment Program, conducts room clearings during a live fire shoothouse as a part of military operations in urban terrain training during Korea Viper 25.4 at Camp Rodriguez, South Korea, May 24, 2025. Korea Viper is a recurring exercise series that demonstrates the Republic of Korea and U.S. Marine Corps' ability to respond decisively in the region as a singular, unified force while strengthening relationships and trust between the two allies. Hurst is a native of Missouri. (U.S. Marine Corps photo by Lance Cpl. Tucker Mocan)

Activated Reserve Marines Conduct Live Fire MOUT during Korea Viper 25.4

Activated Reserve Marines Patrol to a Live Fire Range during Korea Viper 25.4

A U.S. Marine with 2nd Battalion, 23rd Marines, forward deployed with 4th Marine Regiment, 3d Marine Division as part of the Unit Deployment Program, conducts a live fire range during a patrol during Korea Viper 25.4 at Camp Rodriguez, South Korea, May 22, 2025. Korea Viper is a recurring exercise series that demonstrates the Republic of Korea and U.S. Marine Corps' ability to respond decisively in the region as a singular, unified force while strengthening relationships and trust between the two allies. (U.S. Marine Corps photo by Lance Cpl. Tucker Mocan)

2/23 Leaves for UDP

U.S. Marine Corps Staff Sgt. Ezequiel Delatorre, a network chief, with Headquarters and Service Company, 2nd Battalion, 23rd Marines, 4th Marine Division, Marine Forces Reserve, and a native of Oxnard California, counts Marines as they walk into a bus on Marine Air Ground Combat Center Twentynine Palms, California, March 11, 2025.The Marines are headed to Kadena Air Base, Okinawa, Japan as part of Unit Deployment Program 25.1. The activation marks the beginning of an intensive period of training for 2nd Battalion, 23rd Marines as they provide a total force solution in support of the UDP by aligning Marine Forces Reserve’s commitment to Marine Corps strategic objectives. This is first time since 2020 that an entire Reserve infantry battalion has activated to support the Unit Deployment Program. (U.S. Marine Corps photo by Sgt. Scott Jenkins)

A corpsman’s heroic actions save the life of a Marine before an upcoming deployment

U.S. Navy Hospital Corpsman Petty Officer 1st Class Billy Bui, a senior line corpsman with Weapons Company, 2nd Battalion, 23rd Marine Regiment, 4th Marine Division, poses for a photo during an Adversarial Force Exercise at Marine Corps Air Ground Combat Center, Twentynine Palms, California, Dec. 9, 2024. Marines with 2nd Battalion, 23rd Marine Regiment participated in AFX, the primary readiness generating event, prior to their deployment as an opportunity to receive training across all warfighting functions in a realistic and fully resourced environment. This deployment is significant for the Reserve battalion and Reserve force contributing units to support exercises and operations outside of the continental U.S. (U.S. Marine Corps photo by Cpl. Madisyn Paschal)

PRESS RELEASE: Fox Company, 2nd Battalion, 23rd Marine Regiment Leaves for Six-Month Deployment

Fox Company, 2nd Battalion, 23rd Marine Regiment, 4th Marine Division, is part of the first entire Reserve infantry battalion to support a UDP since 1st Battalion, 25th Marine Regiment, deployed in 2020.This deployment is significant for the Reserve battalion, which is spread out across the U.S., and to the Reserve force contributing units to support exercises and operations outside of the continental U.S. The activation marks the beginning of intense training as 2nd Battalion, 23rd Marine Regiment provide a Total Force solution in support of the UDP to align with Marine Forces Reserve’s commitment to the Marine Corps’ strategic objectives while supporting III Marine Expeditionary Force in Okinawa, Japan.

UDP 25.1 PHOTO GALLERY

200414-M-BC936-0040

Lance Cpl. Mathew Dieter, left, and Cpl. Talon Malone, right, both combat engineers with Special Purpose Marine Air-Ground Task Force - Southern Command, level a cylinder block wall during a general exercise at Marine Corps Base Camp Lejeune, North Carolina, April 14, 2020. The combat engineers leveled the wall to help their construction project maintain its overall structural integrity. The GENEX includes training events such as engineering projects and evacuation control center training scenarios that will help build the SPMAGTF-SC for their final certification exercise. These training events also provide the Marines and Sailors with real-world scenarios to prepare them for their deployment to assist partner nation militaries in Latin America and the Caribbean. Dieter is a native of Portland, Oregon. Malone is a native of Estacada, Oregon. (U.S. Marine Corps photo by Cpl. Benjamin D. Larsen)

Download Image: Full Size (2.37 MB)

Tags: MarForRes, usmc, Mortar, marforsouth, HQMC, Portrait, USSouthcom, Special Purpose Marine Air-Ground Task Force - Southern Command, pre-deployment training, Camp Lejeune, Construction, Enduring Promise, SPMAGTFSC, MFRDPC/RSU-East, Deployment Processing Command Reserve Support Unit-East, USMCF-S, General Exercise, GENEX

Photo by: Cpl. Benjamin Larsen | VIRIN: 200414-M-BC936-0040.JPG

Photo Gallery

NEWS AND PRESS RELEASES

PRESS RELEASE: Marine Reserve Battalion Prepares for Deployment to Okinawa, Japan
https://www.marforres.marines.mil/News-Photos/MARFORRES-News/Article/4114762/press-release-marine-reserve-battalion-prepares-for-deployment-to-okinawa-japan/

A corpsman’s heroic actions save the life of a Marine before an upcoming deployment
https://www.marforres.marines.mil/News-Photos/MARFORRES-News/Article/4035917/a-corpsmans-heroic-actions-save-the-life-of-a-marine-before-an-upcoming-deploym/

PRESS RELEASE: Fox Company, 2nd Battalion, 23rd Marine Regiment Leaves for Six-Month Deploymenthttps://www.marforres.marines.mil/news-photos/marforres-news/article/4016149/press-release-fox-company-2nd-battalion-23rd-marine-regiment-leaves-for-six-mon/

Valley Springs Firefighter Deploys with the Marines
https://new.thepinetree.net/?p=187361