Inside a basement laboratory at the Massachusetts Institute of Technology, 27-year-old Bastien Aymon sits at his bench.
"This is my spot," he says, tapping the table covered with paperwork, test tubes and a vacuum chamber.
The fourth-year PhD candidate in mechanical engineering is from Sion, Switzerland. His research here could lead to materials that better integrate with the human body, like pacemakers. One application: stretchy, breathable bandages that absorb moisture and stick to skin tissue.
"Some of the materials we fabricate are very humidity sensitive," he says, firing up the vacuum chamber.
Aymon started his PhD in 2023. Since the Trump administration's proposed new four-year visa cap isn't retroactive, he won't be affected immediately. But some of his friends who started later may be forced to re-apply for their visas or leave the U.S. before they finish their degrees.
"It adds a lot of uncertainty and stress in our daily lives for sure," he says. "And that takes time away from research, which is not ideal."
The Trump administration is changing how long international students can stay in the U.S. before they have to reapply for a visa or leave the country. The new four-year cap takes effect on Sept. 15.
Higher education leaders say it could make it much harder for students to change majors or schools or simply finish their research. Supporters say it's a minor inconvenience that adds important accountability to the student visa system.
But colleges say the new rule is already affecting their campuses and could discourage talented students from even applying.
The change comes as visa backlogs, research funding cuts and freezes, and other policy changes are driving away international talent — and the money these students bring in.
The Association of International Educators estimates foreign enrollment will fall nearly 10% this fall, costing local economies more than $3.4 billion and nearly 40,000 jobs.
"If you have less students coming to study, then it also has an impact on revenues that are coming in and way beyond tuition dollars," said Fanta Aw, CEO of the Association of International Educators, which has joined a lawsuit against the federal government to block the rule.
In court filings, a coalition of higher ed groups says nearly a quarter-million international students are pursuing doctoral degrees, most of them enrolled in STEM fields.
Aw says the government is interfering with decisions traditionally left to colleges.
"It's literally saying to the schools, 'We know better, and we're going to tell you what we think is a normal length of study' — something that is unprecedented because you have government folks who really know nothing about what happens on a day-to-day basis," Aw says.
But backers of the new rule say the requirement is simply a bureaucratic hurdle.
"Look, I spend every weekend a couple hours jumping through hoops and doing [expletive] paperwork," said Simon Hankinson, a senior fellow at The Heritage Foundation. "I don't like it, but I do it because I want to live in a modern world."
Hankinson says the old system gave students too much flexibility.
"Duration of status was a giant loophole that many students exploited," he said. "There's just almost nothing to stop them just going and getting degree after degree or doing a PhD and taking decades to do it."
At MIT, administrators are describing a "numbing" period of relentless federal cuts to research funding. The university has seen roughly a 20% drop in federal funding and cut graduate admissions by roughly the same amount this fall. The new endowment tax is costing MIT around $240 million a year, adding to the financial strain.
Now, they're worried about the new visa cap as well.
"This is untenable for PhD students," MIT President Sally Kornbluth told GBH's Boston Public Radio in July. "Sometimes it takes a year or two to really have all the tools in your toolkit to do something substantial."
Kornbluth says American universities, once global leaders in research, could lose their edge, warning the U.S. could become more dependent on countries such as China for medical breakthroughs.
"Most PhD students take five-and-a-half years, six years," she explained. "If I were an international student and I were worried about my PhD work being cut off, I would be hesitant to come to this country."
Sitting at his bench, wearing a black lab coat, Aymon says visa and funding uncertainty is already changing how students think about their futures.
If international researchers are going to take their talents to the U.S., Aymon says they have to consider whether the environment here will be stable enough to find a spot and build a career.
He led a recent survey of MIT graduate students that found both international and domestic students are now more willing to leave the U.S. after they graduate.
"Some people are just stressed about the current immigration environment," he said. "Science funding is an issue for a majority of people."
Copyright 2026 GBH News Boston