Two University of Pennsylvania Medical Center physicians said suspending immigration from seven Muslim-majority countries will have a negative impact on graduate medical education (GME) and the U.S. healthcare system as a whole.

Writing in the New England Journal of Medicine, Ahmad Masri, MD, and Mourad H. Senussi, MD, argued the executive order from President Donald Trump ignored already stringent requirements for international medical students. They have to sit through several medical exams, apply to a number of programs and travel for an in-person interview.

Nearly 900 physicians from Muslim-majority countries were matched into U.S. residency programs in 2013. If they’re prevented from coming to U.S., a critical pipeline for training new doctors will be closed off.

“The executive order is thus detrimental to GME, a well-designed process that funnels hard-working IMGs into training positions that would otherwise remain unfilled. Since President Trump signed the order, there has been pandemonium among residents, fellows, and GME offices throughout the country. It has created much uncertainty and may well lead selection committees to reconsider their choices of applicants on the basis of country of origin,” Masri and Senussi wrote.

A similar argument was made by American Medical Association CEO James Madara. In a Jan. 27 letter to the Department of Homeland Security, he asked for clarification on the order, saying the current uncertainty risks leaving residency slots vacant in March 2017.

“To date, one out of every four physicians practicing in the United States is an [international medical graduate],” Madara wrote. “These physicians are licensed by the same stringent requirements applied to U.S. medical school graduates. They are more likely to practice in underserved and poor communities, and to fill training positions in primary care and other specialties that face significant workforce shortages.”

According to the chairs of seven academic medical departments, patient care would suffer, too, as international doctors are already struggling with the fallout from the order.

“Within Partners Healthcare (primarily Massachusetts General Hospital and Brigham and Women’s Hospital), for example, more than 100 personnel are affected,” they wrote. “At least 20 people were in the process of either applying for a visa at a U.S. consulate abroad or preparing to travel to the United States. Two were not allowed to board their flights on the day the executive order was issued. Seventy-eight people with active visas from these seven countries have been identified so far. The numbers are even larger when we include green-card holders who are citizens of the designated countries and foreign graduates of U.S. schools holding student-visa work permits.”

The letter in the NEJM was signed by the chairs of Massachusetts General Hospital, Brigham and Women’s Hospital, Beth Israel Deaconess Medical Center, Johns Hopkins Medicine, Baltimore, the University of Michigan Health System, Ann Arbor, University of Pennsylvania Perelman School of Medicine, Philadelphia, and the University of California, San Francisco.