The units stationed at Fort Lewis, now part of Joint Base Lewis-McChord in Washington state, are anchored by I Corps and include the 7th Infantry Division’s two Stryker brigades, an aviation brigade, a field artillery brigade, Army and Air Force special operations units, a full set of sustainment and enabling brigades, and two C-17 airlift wings at McChord Field. Fort Lewis merged with McChord Air Force Base on February 1, 2010 under the 2005 Base Realignment and Closure process, so the Army side is now called Lewis Main and the combined installation is JBLM.1446th Airlift Wing. McChord Becomes Part of Joint Base Lewis-McChord2Joint Base Lewis-McChord. History of Joint Base Lewis-McChord More than 44,000 soldiers are stationed at JBLM and across the Pacific under its senior command, and the base functions as the Army’s westernmost power-projection platform.3The United States Army. Secretary of the Army Visits Americas Power Projection Platform in the Pacific
I Corps
I Corps, known as “America’s First Corps,” is the senior Army command at JBLM. It is a three-star headquarters responsible for more than 44,000 soldiers at JBLM and across the Pacific, including in Hawaii and Alaska.4The United States Army. I Corps Table Drop Its mission is deterrence and, if required, combat operations throughout the Indo-Pacific, and virtually every Army unit stationed on the installation either falls under I Corps or works alongside it.5The United States Army. I Corps
7th Infantry Division and Its Stryker Brigades
The 7th Infantry Division is an active-duty division headquartered at JBLM. It oversees the combat readiness of two Stryker Brigade Combat Teams and a combat aviation brigade.6The United States Army. 7th Infantry Division The two Stryker brigades, the 1-2 Stryker Brigade Combat Team and the 2-2 Stryker Brigade Combat Team, are the base’s primary ground combat formations, built around the eight-wheeled Stryker armored vehicle for rapid infantry operations.7U.S. Army Pacific. I Corps Celebrates 107 Years and First Experiences in 2024 They are lighter than armored divisions but more mobile, well suited to expeditionary work in the Indo-Pacific.
16th Combat Aviation Brigade
The 16th Combat Aviation Brigade is subordinate to the 7th Infantry Division and flies from Gray Army Airfield on Lewis Main.8The United States Army. 16th CAB Night Airfield Operations Its fleet includes AH-64 Apache attack helicopters and UH-60 Black Hawk utility helicopters, and its training routinely centers on Indo-Pacific readiness, including joint air-load exercises for rapid deployment of forces and equipment.9The United States Army. 16th Combat Aviation Brigade Sharpens Lethality, Readiness Across the Indo-Pacific
17th Field Artillery Brigade
The 17th Field Artillery Brigade is JBLM’s long-range fires unit, operating the High Mobility Artillery Rocket System (HIMARS). The brigade trains to deploy quickly, mass rocket and missile fires, and sustain those operations at the speed of modern combat.10The United States Army. 17th Field Artillery Brigade Holds HIMARS Training
Special Operations Units
JBLM carries an unusually heavy concentration of special operations forces across both services.
The 1st Special Forces Group (Airborne) is the Army’s lead Special Forces group for operations in Asia and the Pacific. Its Green Berets train with partner nations across the U.S. Indo-Pacific Command area, and the group maintains forward-deployed elements in Okinawa and elsewhere in the region while headquartered at JBLM.11Army Garrisons. 1st Special Forces Group
The 2nd Battalion, 75th Ranger Regiment is also stationed at JBLM. The Rangers are the Army’s premier direct-action raid force, built to deploy anywhere in the world on very short notice.
On the Air Force side, the 22nd Special Tactics Squadron operates from McChord Field. Special Tactics Airmen specialize in ground-level air integration, airfield seizure, personnel recovery, and battlefield surgery, often working alongside Army special operations forces on joint missions.12Air Force Special Tactics. 22nd STS Hone Global Access Capabilities
Sustainment and Enabling Brigades
A base built around expeditionary operations needs a deep bench of logistics, communications, engineering, intelligence, and medical units. JBLM hosts several.
- 593d Corps Sustainment Command. Formerly the 593rd Expeditionary Sustainment Command, redesignated in April 2025 to reflect its expanded role providing logistics and sustainment support for I Corps across the Indo-Pacific.13The United States Army. 593rd ESC Redesignation Strengthening Logistics for the Indo-Pacific Mission
- 22nd Corps Signal Brigade. The Army’s newest signal brigade, activated to provide expeditionary communications and command-and-control network capabilities for I Corps and U.S. Army Pacific.14Line of Departure. Activating the Armys Newest Signal Brigade
- 555th Engineer Brigade. Combat and general engineering support for I Corps operations.
- 201st Expeditionary Military Intelligence Brigade. Intelligence collection, analysis, and support for the corps and its subordinate units.
- 62nd Medical Brigade. Deployable medical forces including forward surgical teams that train at Madigan Army Medical Center.15The United States Army. 62nd Medical Brigade Soldiers Operate Surgical Suites at Madigan to Strengthen Warfighting Readiness
- 404th Army Field Support Brigade. Installation-level logistics support to Army units and other Department of Defense organizations at JBLM.
- 189th Infantry Brigade. A First Army unit focused on training and readiness oversight for reserve component forces.
Air Force Units at McChord Field
McChord Field is home to two airlift wings that together operate 40 C-17 Globemaster III aircraft, the Air Force’s primary strategic transport plane.16Team McChord. Look at All Those C-17s
The 62nd Airlift Wing is the active-duty wing. Beyond routine airlift, it holds two distinctive missions: it is the Department of Defense’s only wing tasked with Prime Nuclear Airlift Forces, and it is the primary active-duty wing supporting Operation Deep Freeze, the military logistics backbone of the National Science Foundation’s U.S. Antarctic Program.17Joint Base Lewis-McChord. Commander, 62d Airlift Wing
The 446th Airlift Wing is the Air Force Reserve associate wing at McChord, flying the same fleet of C-17s alongside the 62nd. The two wings share aircraft while each keeps its own crews and command structure, giving McChord surge capacity when demand climbs.18Team McChord. Team McChord – Units
Other Tenant Organizations
The Western Air Defense Sector (WADS) is an Air National Guard unit headquartered at McChord Field. It is responsible for air sovereignty over the western half of the continental United States, operating under NORAD and controlling alert fighter jets, primarily F-15s and F-16s, along with radar coverage across the western states.19Washington State Military Department. Western Air Defense Sector
Madigan Army Medical Center, one of the Army’s largest medical facilities, sits on the installation. It offers general and surgical care, a 24-hour emergency room, specialty and pediatric clinics, and a behavioral health department with the largest number of behavioral health providers in the Army, serving TRICARE-eligible beneficiaries in the region.20Joint Base Lewis-McChord. For Patients
JBLM also hosts the 8th Brigade of the U.S. Army Cadet Command, which oversees ROTC programs across its region, along with elements of the Washington National Guard.