While the Trump administration is fighting, in the courts of justice and public opinion, for its temporary travel ban affecting six countries, the slowdown in the rural doctor pipeline shows how even a small, relatively uncontroversial change can ripple throughout the country.
In Montana, for example, where nine counties do not have a single physician, it means Benefis Health does not know when a Romanian doctor trained in kidney transplants will arrive. The health care company spent months recruiting the doctor and had been expecting her in July.
“Our health system already has nine months invested in her, and now we have no idea when she can start,” said Erica Martin, who recruits doctors for the company.
The doctor, Silviana Marineci, who is completing a fellowship at the University of Minnesota, said she was frazzled by being in limbo.
“I won’t have an income, I don’t know if I will afford rent, I don’t know where I will be,” she said. “It’s insane.”
The procedural change regards temporary visas for skilled workers, known as H-1B visas. United States Citizenship and Immigration Services recently announced that it would temporarily suspend a “premium processing” option by which employers could pay an extra $1,225 to have H-1B applications approved in as little as two weeks, rather than several months.
Companies using that option, the government said, have effectively delayed visas for others who did not pay the extra fee.
A spokeswoman for the immigration agency, Arwen Consaul, said in a statement that the measure was necessary to “work down the existing backlogs due to the high volume of incoming petitions.”
The H-1B program has raised questions about whether it displaces American workers, particularly in computer programming and engineering jobs, for which most of the visas are issued.
H-1B recipients also include foreign physicians who practice in places shunned by American doctors for personal and professional reasons.
About 25 percent of all physicians practicing or training in the United States are foreign, but in some inner cities and most rural areas, that share is significantly higher.
There were 211,460 international medical graduates practicing in the United States in December 2015, according to the latest data available from the Educational Commission for Foreign Medical Graduates.
Senators Amy Klobuchar, a Minnesota Democrat; Susan M. Collins, Republican of Maine; and Heidi Heitkamp, Democrat of North Dakota, have urged the agency to continue premium processing.
“Slowing down this successful two-decade-old program and the doctors it brings to rural areas will hurt families across North Dakota and rural America,” Ms. Heitkamp wrote in an email.
It was a North Dakota senator, Kent Conrad, who in 1994 proposed to relieve a shortage of doctors by tapping foreign physicians who have completed medical education in the United States.
His program waives the requirement that foreign doctors who graduate from residency programs in the United States return to their home countries for two years before working here. It lures such graduates to practice in underserved areas by offering them the chance to apply for a green card to live permanently in the United States after three years.
The program must be reauthorized by Congress every two years. Ms. Klobuchar, who twice has introduced legislation to make the program permanent, plans to do so again in the coming weeks.
Since the program’s inception, tens of thousands of foreign physicians in a variety of specialties have flocked to clinics and hospitals in Appalachia, the Mississippi Delta region, the Great Plains and elsewhere.
Many of them, such as Dr. Fadel E. Nammour, the vice president of the North Dakota Medical Association, put down roots and never leave.
The friendliness that he found in Fargo reminded him of his home country, Dr. Nammour said. As a token of his gratitude, one of his first patients brought him a Styrofoam box filled with freshly caught walleye, a fish that thrives in the state’s lakes.
“We provide not only the care but also our leadership,” said Dr. Nammour, who is now an American citizen. “The focus should be on making it easier to bring people in to cover the physician shortage we have.”
The delay also could affect the roughly 400 foreign medical graduates who come each year to participate in residency programs at teaching hospitals. The doctors were matched on Friday for residencies starting July 1 across the country.
“Everyone around the country will be in a mad scramble to figure out this visa situation,” said Michelle Larson-Krieg, the director of international student and scholar services at the University of Colorado in Denver, which usually takes 10 or 12 residents on H-1Bs each year at its Anschutz Medical Campus.
The immigration agency said in a statement that applicants could still request an H-1B approval on an “expedited basis,” if they could prove there was an emergency or humanitarian justification.
Immigration lawyers said that it was extremely difficult to meet that standard, and that they doubted whether the agency could handle a flood of such requests.
“If they don’t have the manpower to do premium processing, I don’t see how they are going to do special requests,” said Andrea Szew, a lawyer in Los Angeles.
In the meantime, hospitals and clinics are adjusting to the possibility of being without some doctors for a while. Ms. Martin of Benefis Health said the hospital would have to give other doctors additional shifts or hire costly temporary physicians, who are frowned upon because they cannot develop a rapport with patients during their brief stints or provide continuity of care.
Ms. Martin said Benefis Health was also recruiting other foreign physicians who could end up in the same situation as Dr. Marineci. “The most problematic thing is the unknown” about when the doctors can start, she said.
Rom Satchi, a Canadian who completed his pediatric residency at the University of Illinois College of Medicine at Peoria, was invited for interviews at facilities in Alabama, Arkansas, Kansas, Pennsylvania and several other places desperate for a pediatrician.
Ultimately, Dr. Satchi signed a contract with Mama Mia Pediatrics in northern Las Vegas, a working-class area that has been struggling to handle a swelling patient caseload. He agreed to start in mid-June.
But now, it is uncertain whether he will be able to get his visa in time.
“At this point, I have no voice,” said Dr. Satchi, who plans to return to Canada and wait, jobless, until the visa is approved. “I can’t do anything.”
An earlier version of this article referred inaccurately to the number of foreign physicians working in North Dakota. There are hundreds, not thousands.