Every March, doctors across the United States and the world eagerly await “Match Day” — the day they find out what residency, internship, or fellowship program they’ve been matched with. By that point, residency candidates have completed medical school and passed a series of rigorous qualifying exams. For those who are not American — about a quarter of all doctors in the U.S. are foreign-born — there’s one additional step: securing a J-1 visa, a nonimmigrant exchange visa conditioned on an individual’s return to their home country for at least two years at the conclusion of the program.

In the weeks following the March 17 match, dozens of Pakistani physicians had their J-1 applications denied in Islamabad and Karachi, said Shahzad Iqbal, a Pakistani-American physician in New York.

Jan Pederson has spent the last 30 years of her legal career representing foreign-born physicians coming to the U.S. for residency or fellowship programs. It’s an unheralded but essential line of work, because without foreign doctors, the U.S. healthcare system would simply collapse, with the pain felt most acutely in rural areas. U.S. medical schools don’t produce anywhere near enough graduates to meet the needs of the country, particularly in places where people are reluctant to move to.

Like any legal practice, Pederson’s hasn’t always been smooth. Every so often, a client’s visa application is denied. It happens. In the years following the Sept. 11 terror attacks, doctors from countries, such as Iran and Syria, saw their applications get stuck in administrative processing until U.S. officials could affirmatively say the physicians posed no national security threat, she said.

But this spring, weeks after President Donald Trump issued a revised version of an executive order restricting immigration from six Muslim-majority countries, Pederson saw the same thing Iqbal did — what she called an “epidemic of Pakistani visa denials.”

Advocates say there is no way to separate the attempted Pakistani physician ban from the so-called Muslim ban and other Trump administration immigration policies.

“I think it’s a confluence of factors” that caused the visa denials, Pederson said. “It would be hard to escape the conclusion” that there is a correlation between the visa denials and the president’s anti-immigration rhetoric and policies.

“This year, we had about 34 J-1 refusals that were reported to us. This is kind of a historic number,” said Iqbal, who chairs the Committee on Young Physicians, which is a part of the Association of Physicians of Pakistani Descent of North America. APPNA only knows about denials that rejected applicants reported to them, so it may be just the tip of the iceberg. Many reapplied, starting from scratch, and were successful, but started their programs late.

APPNA has lobbied on behalf of Pakistani doctors hoping to train in the United States since 2003, Iqbal said. Heightened post-9/11 security measures meant that many visa applications were held up in administrative processing, but “it never happened before that there was a mass number of denials,” he said. “Before, there were security clearances, and people were placed in security clearance for six months to two years.”

For the last five years, APPNA received reports of, at most, one or two physicians whose visa applications were denied, and usually it was because of an issue with an applicant’s immigration history.

This is concerning, Iqbal said, since Pakistan is one of the top suppliers of foreign doctors to the U.S. In 2015, 12,125 doctors of Pakistani descent were practicing medicine in the U.S., second only to India’s 46,137 doctors, according to the U.S. Organization for Economic Cooperation and Development.