Foreign-born physicians have become crucial to the delivery of medical care in the United States. They work in small towns where there are no other doctors, in poor urban neighborhoods and in Veterans Affairs hospitals.

Forty-two percent of office visits in rural America are with foreign-born physicians, according to the American Academy of Family Physicians.

Foreign-born physicians "are the doctors in small towns in Maine and Iowa," said Dr. Patricia F. Walker, the associate director of the University of Minnesota's Global Health Pathway, which helps refugee doctors practice in the United States.

"They go to the places where graduates of Harvard Medical School don't want to go," she said.