Disaster Medical Assistance Teams (DMAT) were founded in response to the devastating Hanshin-Awaji Earthquake in 1995, which revealed the need for immediate medical intervention under rubble. The earthquake resulted in many casualties due to crush syndrome, and it was recognized that approximately 500 deaths could have been prevented with timely medical care. In the wake of the disaster, the importance of deploying medical teams within 48 hours to provide critical care for seriously injured individuals became clear, leading to the establishment of disaster base hospitals from which self-sufficient medical teams could operate.

The inception of DMAT as a national organization came after challenges were faced during the 2004 Niigata-Chuetsu Earthquake, where delays in deployment hampered response efforts. This highlighted the need for a trained and organized response team, leading to the formal establishment of DMAT in April 2005. DMAT's initial activation occurred during the derailment of the JR Takarazuka Line, marking a crucial point in Japan's disaster response system. Today, DMAT teams are comprised of trained medical professionals who carry their own food and supplies to ensure they can function autonomously for several days in affected areas.

Initially focused on providing critical care to the injured, the role of DMAT teams has evolved, especially after the Great East Japan Earthquake in 2011, shifting towards supporting hospitals in disaster recovery rather than just performing emergency medical procedures. This transition reflects broader changes in disaster response strategies, emphasizing the importance of hospital support and continuity of care in the aftermath of large-scale disasters, aligning with the changing landscape of healthcare demands in crisis situations.