Response is one of the core activities of disaster management, and it refers to the actions taken directly before, during, or immediately after a disaster in order to save lives, reduce health impacts, ensure public safety, and meet the basic subsistence needs of the people affected. The objective of the response phase is to save lives, ensure health and safety, and meet the subsistence needs of the people affected. The response phase is a reaction to the occurrence of a catastrophic disaster or emergency.

The response phase involves the coordination and management of resources, including personnel, equipment, and supplies, utilizing the Incident Command System in an all-hazards approach. The institutional elements of response often include the provision of emergency services and public assistance by public and private sectors and community sectors, as well as community and volunteer participation. Emergency services are a critical set of specialized agencies that have specific responsibilities in serving and protecting people and property in emergency and disaster situations.

Effective, efficient, and timely response relies on disaster risk-informed preparedness measures, including the development of the response capacities of individuals, communities, organizations, countries, and the international community. Responders are interdisciplinary and from a wide variety of backgrounds, and disaster plans need to have minimal complexity and be widely applicable; the correct resources need to be activated; the incident command structure must be respected; and, responders need to be well trained.

The response phase is followed by the recovery phase, which consists of those activities that continue beyond the emergency period to restore critical community functions and begin to manage stabilization efforts. The goal of the recovery phase is to bring the affected area back to some degree of normalcy. Mitigation is the effort to reduce the loss of life and property by lessening the impact of disasters and emergencies. Mitigation involves structural and non-structural measures taken to limit the impact of disasters and emergencies.