The United States is in the midst of a prolonged nursing shortage, one that could reach a deficit of 800,000 registered nurses (RNs) by 2020. Increasingly, foreign-trained nurses are migrating to the U.S., particularly from low-income countries, seeking higher wages and a higher standard of living. Increased reliance on immigration may adversely affect health care in lower-income countries without solving the U.S. shortage. This Issue Brief analyzes trends in medical migration, and explores its short and long-term effects on the health care workforce in the U.S. and in developing countries.