Marine Corps Air Station Iwakuni

Branch: U.S. Marine Corps
Location: Iwakuni, Yamaguchi Prefecture, Japan
Installation Type: Marine Corps Air Station
Status: Active

Overview

Marine Corps Air Station Iwakuni is located in Iwakuni City, Yamaguchi Prefecture, Japan, approximately 40 kilometers southwest of Hiroshima on the coast of the Seto Inland Sea. MCAS Iwakuni is the home of Marine Aircraft Group 12 (MAG-12) and is the only permanent U.S. Marine Corps aviation base in Japan. The installation operates F/A-18, F-35B, EA-18G Growler (Navy), and KC-130J aircraft, providing a combined Marine/Navy aviation presence. Iwakuni underwent a significant $3.3 billion transformation beginning in 2012, culminating in the relocation of an F/A-18 carrier air wing (CVW-5) from Naval Air Facility Atsugi to Iwakuni in 2017, doubling the base’s size and population. The base is shared with the Japan Maritime Self-Defense Force (JMSDF).

Mission & Units

Primary Mission: Provide Marine Corps and Navy aviation for Pacific Air Forces and Indo-Pacific Command; conduct tactical aviation operations supporting III Marine Expeditionary Force (III MEF); homeport carrier air wing aircraft in Western Japan.
Major Units: Marine Aircraft Group 12 (MAG-12); Marine Fighter Attack Squadron 242 (VMFA-242, F-35B); Marine All Weather Fighter Attack Squadron 225 (VMFA(AW)-225, F/A-18D); Marine Aerial Refueler Transport Squadron 152 (VMGR-152, KC-130J); Carrier Air Wing FIVE (CVW-5) aircraft (F/A-18E/F, EA-18G, Navy tenant)
Tenant Units: JMSDF P-1 Maritime Patrol Aircraft; Commander, Fleet Activities Iwakuni (Navy); Fighter Squadron Composite FIVE (VFC-5, Navy adversary); various Navy and Marine Corps support elements

Location & Access

Nearest Major City: Iwakuni City (population approximately 130,000) – immediately adjacent; Hiroshima – approximately 40 km northeast; Yamaguchi City – approximately 45 km west; Osaka – approximately 300 km northeast
Nearest Commercial Airport: Hiroshima Airport (HIJ) – approximately 60 km northeast; Iwakuni Airport (IWK) shares the base airfield with some commercial flights; Osaka Kansai International Airport (KIX) – approximately 300 km northeast (accessible by Shinkansen)
Gate Access: Main gate; CAC/military ID required; visitor passes at Visitor Control Center; joint base with JMSDF requires coordinated access protocols; Japan SOFA access procedures apply

Population

Active Duty Personnel: Approximately 5,000 (doubled after CVW-5 relocation in 2017)
Family Members: Approximately 6,000
Civilian Employees: Approximately 1,500
Total Installation Population: Approximately 12,500

Key Facilities

Medical: Naval Health Clinic Iwakuni – primary care, dental, behavioral health, and flight medicine; specialty referrals to Japanese hospitals in Hiroshima (Hiroshima University Hospital is excellent) or Tokyo for complex cases; medevac to CONUS or Yokota for major cases
Commissary: Yes – commissary on base; critical for American food products given remote western Japan location
Exchange (PX/BX/NEX): Yes – Marine Corps Exchange (MCX) / AAFES exchange and facilities; new facilities opened as part of the base expansion
Fitness & Recreation: Fitness centers; indoor and outdoor pools; golf course; bowling; auto skills; Seto Inland Sea access for water recreation; Hiroshima day trips; onsen (hot springs) throughout the region; Miyajima Island (floating torii gate, UNESCO, 40 km, one of Japan’s most iconic views)
Schools: Department of Defense Education Activity (DoDEA) Iwakuni Elementary School; Matthew C. Perry Middle School; Matthew C. Perry High School – DoDEA serves all military children; school expanded significantly with the 2017 base population increase
Childcare: Child Development Center on base; waitlists possible; register early; Japan pet import rules apply for those bringing pets
Veterinary Services: Veterinary Treatment Facility on base; wellness and preventive care; Japan’s strict 180-day rabies antibody waiting period must be observed before arrival
Legal Assistance / JAG: Legal Assistance Office; appointment-based; Japan SOFA matters through JAG

Housing

On-Post Housing: Government quarters on base; significantly expanded family housing as part of the 2012-2017 base modernization; condition generally good to excellent; new housing built during expansion
Average Wait Time: 30-60 days typical; on-base housing is preferred given Japanese housing market differences
Off-Post Housing: Iwakuni City and surrounding Yamaguchi Prefecture communities offer economy housing; OHA applies; Japanese housing is smaller than American standards; living in Iwakuni City provides authentic rural Japanese experience; some families in Hiroshima for more urban living (with longer commute)
OHA Rate Reference: Check current OHA rates at Defense Travel Management Office (dtmo.mil); Iwakuni OHA reflects Yamaguchi Prefecture rental costs

PCS & Newcomer Info

Sponsorship Program: Contact gaining squadron or command; MAG-12 and CVW-5 squadron sponsorship programs; Iwakuni PCS requires 180-day pet import planning if bringing pets
In-Processing: MCAS Iwakuni in-processing; typically 3-5 days; Japan SOFA briefings; vehicle registration; ration card; medical enrollment; curfew briefing
EFMP (Exceptional Family Member Program): Family Services Center; enrollment required; EFMP screening mandatory before Japan orders; Hiroshima has excellent medical care; Tokyo for complex cases; EFMP approval process for Japan is stringent

Local Area & Quality of Life

Climate: Humid subtropical; warm summers (average high 88F/31C in July-August); cool winters with some snowfall (average low 32F/0C in January); mild spring and fall; significant rainfall in June (rainy season/Tsuyu); typhoon risk July-October; Seto Inland Sea climate is somewhat milder than the Pacific coast
Cost of Living: Moderate; Iwakuni and Yamaguchi Prefecture are moderately priced by Japanese standards; significantly less expensive than Tokyo or Osaka; exchange and commissary reduce costs; OHA typically adequate; yen-dollar exchange rate affects costs
Nearby Attractions: Miyajima Island and the floating Torii gate (UNESCO, one of Japan’s three scenic views, 40 km; itsukushima Shrine); Hiroshima Peace Memorial Park and Museum (atomic bomb memorial, UNESCO, 40 km) – one of the world’s most moving and important memorial sites; Hiroshima Castle; Kintaikyo Bridge (Iwakuni’s iconic historic bridge, immediately adjacent to base); Nishiki River and Iwakuni Castle; Matsuyama (Shikoku Island ferry, 2 hours); Osaka/Kyoto accessible by Shinkansen (2.5 hours); Tokyo (4 hours by Shinkansen); Yamaguchi Prefecture hot springs; Akiyoshido Limestone Caves (90 km)
Spouse Employment: On-base employment through NAF, MCX/AAFES, commissary, DoDEA, and contractor positions; off-base employment requires Japanese work authorization; English tutoring popular; remote work common; time zone difference with U.S. creates challenges; Family Services Center assists; the smaller Iwakuni community (compared to Okinawa or Tokyo) creates strong spouse support networks

OCONUS-Specific Information

SOFA: U.S.-Japan Status of Forces Agreement (SOFA) governs U.S. personnel; covers legal jurisdiction, criminal proceedings, customs, vehicle registration, and USFJ policies; same SOFA framework as other Japan bases
Host Nation Rules: Japanese laws apply off-base; curfew strictly enforced; noise regulations; waste separation required; Japanese customs – remove shoes indoors, bowing, gift-giving etiquette; Iwakuni locals have coexisted with U.S. military for decades and are generally welcoming
Curfew: USFJ curfew: midnight to 0500 for all USFJ personnel; strictly enforced; violations subject to disciplinary action
Ration Card / Customs: USFJ ration card for tax-free purchases; limits on alcohol, tobacco, and some electronics; customs declaration required when departing Japan; medication import restrictions (many U.S. medications require advance authorization)
Vehicle Registration: SOFA vehicles with JA plates; Japanese Compulsory Insurance (JCI) required; Japanese/SOFA driver’s license; left-hand traffic; mandatory base driver’s training before off-base authorization
Language and Culture: Japanese; Yamaguchi Prefecture dialect; some English near base; learning Japanese greatly enriches the assignment; Japanese cultural values – precision, cleanliness, respect, group harmony; Iwakuni has a strong samurai and castle heritage
Currency and Banking: Japanese Yen (JPY); on-base banking; ATMs throughout Iwakuni and Hiroshima; Japan increasingly cashless in urban areas; exchange rate fluctuates
Travel Restrictions: Freedom of movement throughout Japan; Shinkansen and domestic flights provide access to all Japan; USFJ travel notification for some international destinations; North Korea travel prohibited
Mail: APO AP address assigned; APO mail through military postal system; Japan Post available for local mail; packages from U.S. to APO AP; customs declaration required
Pets: Same Japan requirements as other Japan bases: ISO microchip, two rabies vaccinations in sequence, FAVN titer test meeting 0.5 IU/mL threshold, 180-day waiting period post-titer before Japan arrival, USDA-endorsed health certificate, import notification to Quarantine Station; begin process minimum 180 days before departure; dogs and cats only through simplified process; non-compliance results in up to 180-day quarantine in Japan at owner’s expense

Last updated: 2026-02-23
Sources: https://www.mcasiwakuni.marines.mil; https://installations.militaryonesource.mil/in-depth-overview/marine-corps-air-station-iwakuni; https://en.wikipedia.org/wiki/MarineCorpsAirStationIwakuni