In January 1989, McDonnell Douglas Helicopters officially announced the launch of the Explorer, which it initially referred to as the MDX.

McDonnell Douglas Helicopters became a launch customer for Pratt & Whitney Canada's PW200 turboshaft engines, for which it had an exclusive agreement to power the first 128 Explorers with pairs of PW206As.

[3][4] On 29 May 1997, all Explorers were temporarily grounded following the discovery of a broken drive-link; during the following month, flight operations resumed after the FAA gave its approval of a redesigned component that addressed the issue.

[8][9] During November 1999, the JAA recommended that all 27 member nations certify the Explorer series for Category A single pilot IFR operations.

[18] Reportedly, by 2015, almost 50 percent of all MD 900/902 Explorers produced were being operated in Europe in three areas of the market: emergency medical services (EMS), law enforcement and military/para-military organizations.

[19] During March 2015, MDHI announced that it was in the process of redesigning the MD Explorer with a higher level of in-house content with the intention of making it more affordable and thus boost sales.

[21] By August 2022, while the MD Explorer series was still technically in production, some operators were facing difficulties obtaining some crucial components and the supply chain was reportedly drying up.

The fuselage is composed of composite materials, such as carbonfibre, that are resistant to corrosion even in hostile marine environments, it also incorporates lightning strike protection measures.

The benefits of NOTAR have reportedly included reduced pilot workload, greatly minimised external noise levels, and significant improvements in safety, particularly when operating in confined areas and from offshore platforms, along with general performance and controllability enhancements.