Medical Ministry International is a nonprofit organization that utilizes volunteers—both medical and non-medical—to bring life-changing services to the poor in areas of North America, such as Texas and Mexico, as well as in countries in Asia, Central and South America, Europe, Africa, and the Middle East.
Please see this link for current volunteer openings.
Agape Unlimited is a nonprofit organization whose goal is to promote health and meet the needs of the medically underserved in the former Soviet Union. This includes working in far remote villages and in large inner cities.
Doctors, physician assistants, nurses, and nurse practitioners may volunteer.