Nongovernmental organizations (NGOs) are predominantly European national or international, nonprofit citizen's voluntary organizations. They are involved in such diverse activities as education, technical projects, relief, and refugee and development programs. Examples of NGOs include, but are not limited to, religious; peace, disarmament, environmental, development, and human rights groups.

Private voluntary organizations (PVOs) are private, US-based, nonprofit organizations involved in humanitarian efforts including, but not limited to, relief, development, refugee assistance, environment, public policy, or global education.

International organizations (IOs) are organizations, such as the United Nations (UN) and the International Committee of the Red Cross (ICRC), with global influence.

Particularly during humanitarian missions, non-governmental organizations (NGO's) may be present, helpful, or in need of assistance. Sometimes, the bulk of the medical care is provided by these NGO's.

Some of these medical departments and organizations are considered here.

*Reprinted from: Operational Medicine 2001,  Health Care in Military Settings, NAVMED P-5139, May 1, 2001, Bureau of Medicine and Surgery, Department of the Navy, 2300 E Street NW, Washington, D.C., 20372-5300