The C-37B is the most recent Gulfstream to be adopted for service with the US Government and its military services. As with earlier Gulfstreams, the G550-based C-37B is most often used by the government to transport high priority Administration, Congressional, and senior DoD and military personnel. The C-27B is outfitted with an advanced communications suite enabling reliable, worldwide, secure, data and voice connectivity for US Government officials.

The C-37B follows in the footsteps of earlier Gulfstream transports (designated as various models of the C-20) which began service with the US Government and military in 1983. C-20 and C-37 model Gulfstreams serve with every branch of the US military forces and with numerous federal agencies including NASA, NOAA, FEMA and others. Gulfstreams are in fact, the only fixed wing aircraft that serve in every branch of the US military.

Two JCG Gulfstreams fill the Japanese Coast Guard's requirement to survey its extensive ocean patrol areas. The aircraft has a 19 passenger high density interior, a belly radome which houses a surveillance radar along with a Forward Looking Infrared (FLIR) system. The radar and FLIR are integrated through software that allows the radar to find a target, pass its location to the FLIR, and to have the FLIR then visually sight and identify the target. The radar, FLIR, and communications suites are operated by on-board missions specialists.

The long range, exceptional endurance, high speed, and operational flexibility of the GV-based JCG aircraft enables the JCG to conduct lengthy broad-area oceanic surveys and patrols. In addition, the aircraft is a superb extended range search and rescue (SAR) platform as well. The aircraft is capable of ocean surveillance at any altitude from near sea level to 51,000' and further, is equipped to drop a variety of SAR equipment such as pumps, rafts, radios, and food and water to those in peril on the sea.

HIAPER is one of the leading US high altitude atmospheric research aircraft. It features cutting-edge scientific research capabilities and is owned by the National Service Foundation Laboratory at the National Center for Atmospheric Research (NCAR) in support of NSF science projects. NCAR is managed by the University Corporation for Atmospheric Research and is sponsored by the National Science Foundation.

The HIAPER aircraft is highly modified. It is fitted with a variety of apertures, fuselage mounts, fuselage pads, optical view ports, wing hard points (pylons and pods), and standardized instrument racks in order to support a broad range of atmospheric and related science experiments. HIAPER is currently operational and is widely considered to be one of the most effective tools available to modern atmospheric research.

The three SEMA aircraft operational with the Israeli Air Force are among the most technically advanced and modern intelligence, surveillance, and reconnaissance (ISR) aircraft in service today anywhere in the world. Operational since 2005 and combat proven in 2006, the Israeli SEMA aircraft from an important layer in the country's bulwark defensive network.

With hours of endurance avaiable on-station and with on-board operators and off-platform data-links, SEMA provides an unmatched electronic surveillance platform. Active with the Israeli Air Force during the 2006 Lebanon War, the first delivered SEMA aircraft went into action only a very short time after reaching its initial operational capability.

Two highly modified CAEW aircraft were delivered to Elta Systems Ltd., a subsidiary of Israeli Aircraft Industries (IAI) in 2006 for installation of Elta's conformal airborne early warning radar system. CAEW provides improved performance compared to previous systems through higher operating altitudes, longer range, and increased mission time on station. Further performance advantages result from its capability to quickly direct radar beams in any direction at any time. The Elta system features six multi-purpose operator stations with color monitors.

The system provides rapid target acquisition and information with full 360 degree coverage. The multi-functional Elta EL/W-2085 AEW system includes a phased array airborne early warning radar, and identification friend or foe system, electronic support measures (ESM), and electronic intelligence (ELINT) and communications intelligence (COMINT) systems. Its many modes of operation include track initiation, an extended detection range mode with long dwell times, and target verification.

The Government of Singapore has placed four Gulfstream-based CAEW early warning aircraft in service.

HALO, like its US predecessor, HIAPER, is a high-altitude atmospheric research aircraft for the Deutsches Zentrum für Luft und Raumfahrt (DLR), Germany, with mission objectives and capabilities similar to those of HIAPER. HALO is supported by the German Research Foundation, Max Planck Society, members of the Helmholtz Association of German Research Centres (Helmholtz-Gemeinschaft Deutscher Forschungszentren), and a number of other scientific institutes from the field of atmospheric research. Around 30 research institutes participate in the project.

HALO's exceptional maximum altitude, range, and payload capabilities represent a significant improvement compared with similar research aircraft in operation previously. HALO is designed to maximize payload flexibility but is typically equipped with as many as 15 equipment racks for scientific instrumentation (more than twice as many as on previous DLR aircraft). Even before HALO was delivered, more than 100 instrument proposals were submitted to DLR from the atmospheric science community, including analysis of trace gases and particles, remote sensing LIDAR and infrared spectrometers, and instruments for investigating geophysical parameters.