After future doctors finish medical school, they go on to residency programs to wrap up their training in hospitals. Both American and foreign medical-school graduates can apply to American residency slots, and among this year’s foreign applicants, there are currently 260 people from the seven nations—Iraq, Syria, Iran, Libya, Somalia, Sudan, and Yemen—banned from coming to the U.S. for 90 days under President Trump’s executive order, according to the Association of American Medical Colleges.

Because the total number of residency slots are limited, many of these individuals might not become American doctors. The typical primary-care doctor sees 3,000 patients, so the AAMC is estimating those 260 future doctors would have been able to take care of more than three-quarters of a million American patients.

Foreign medical students typically come to the U.S. under J1 or H1 visitors’ visas, which are subject to Trump’s 90-day ban. Residency matching typically happens in March, and residents start in June. That’s more than 90 days away, but “the uncertainty is throwing people off,” said Atul Grover, the director of the AAMC, which oversees the residency matching program.

“The program directors are like, ‘what do I do?’” Grover told me. “If there’s someone who I think is going to make a fantastic doctor from Sudan, are we going to be able to take them?”