She called them one at a time, working her way through medical records family by family, hoping to convince the undocumented and uninsured to bring their children back to the hospital.

They could receive free care from doctors, nurses, nutritionists, she explained. They could finally get their children’s diabetes under control. All they had to do was show up.

Frustrated by the limited medical care available to immigrant children who had been brought into the United States illegally, Jennifer Boughton, a social worker at Children’s National Hospital in Northwest Washington, launched a clinic last year that provides comprehensive care to kids who suffer from diabetes but are not eligible for medical coverage because of their immigration status.

Boughton assured families that the hospital was a safe place, that their immigration status and personal information would not be shared. The clinic would run four times a year, enough to provide consistent follow-up care. And yet, on the opening day, just one family came.

A year later, the number of patients has grown to nine, but hospital workers said the clinic has the capacity to treat many, many more.

They’re just not sure how to get them in the door.

Clinics that treat immigrant populations across the United States have struggled to draw patients amid heightened fears of federal immigration raids. In a national poll of health-care providers, the Migrant Clinicians Network found earlier this year that 68 percent of those surveyed said their immigrant patients have been fearful and reluctant to seek medical help amid the Trump administration’s crackdown.

“The courage that it takes to come to the clinic in the first place, I don’t take that for granted,” Boughton said. “It’s really challenging because there are programs we could refer the families to, and we’ve offered, but a lot of them say no because they have to put things like their names and addresses down on a piece of paper. That’s why we try to keep everything in-house.”

Before the clinic opened, Boughton said, doctors at Children’s National Hospital would admit uninsured diabetic children for emergencies and send them home with little follow-up, other than telling them to buy insulin over the counter.

Boughton said she and other hospital workers felt it was “unethical” to continue treating diabetic undocumented kids only when they were brought into the emergency room with dangerously low blood sugar, knowing the problems that landed them there would probably continue after they left.

Diabetes can be deadly in children. It is an incurable but treatable disease. Consistency is key, said Fran Cogen, the hospital’s director of diabetes services.

That can be a challenge for low-income families without health insurance.

A diabetic teen can need up to four vials of insulin a month, Cogen said. The cost can range from $25 to $100 per vial, putting the medicine out of reach for some families without insurance coverage.

Of course, medical costs can be a burden for all American families — with or without insurance. The difference is that when uninsured American children are brought into the hospital, social workers can help families apply for and receive coverage through programs such as Medicaid, Boughton said.

People living in the country illegally are generally prohibited from enrolling in Medicaid or Medicare or buying insurance through marketplaces set up by the Affordable Care Act, commonly known as Obamacare. Mothers and children also do not qualify for the Children’s Health Insurance Program (CHIP).

In the District and six states — California, Illinois, Massachusetts, New York, Oregon and Washington — low-income children are eligible for health-care coverage subsidized by the local government, regardless of immigration status.

But just over the border in Maryland and Virginia, undocumented children with diabetes and other chronic illnesses remain uninsured.

“This is a group of people who have extreme barriers and very limited access to care,” Boughton said. “We’re all human, and we should help any family who needs it. Especially children. If this was your kid, you would want them to receive the care.”

At the clinic on Friday, the fourth since the program’s inception, families gathered around a conference table waiting their turn to cycle through care stations that include meetings with doctors, nurses, psychologists and more.

A teenage boy practiced pricking his finger to check his blood glucose levels as his father looked on from the back of the room. A Spanish interpreter stood by his side, quietly translating the nurse’s instructions to his son.

“You like torturing yourself, huh?” clinical instructor Sue-Ann Arboine said to the 17-year-old as he pricked the pad of his right thumb. He shrugged. Arboine laughed.

“That’s okay,” she said. “You do whatever works for you.”

For hours, Boughton flew between the rooms, checking on patients and monitoring supplies.

Funded by $55,000 in private donations, the clinic provides a one-stop shop for families, where diabetic children can receive individualized care and a three-month supply of medicine, monitors and other items.

A dark-haired 15-year-old boy, the clinic’s first-ever patient, stood with his mother, picking at his gray sweatshirt in the Diabetes Center’s waiting room.

He was diagnosed with Type 1 diabetes when he was 7, after going into a diabetic coma in his home country of El Salvador.

The boy’s mother, who moved to the United States when he was just 3, leaving him to live with his grandmother, said she thought the diagnosis was a death sentence.

“I didn’t think he would be able to survive,” said the mother, who spoke on the condition of anonymity because of her and her son’s immigration status.

For most of his youth, the boy spent birthdays in the hospital. His glucose levels were out of control.

In the last year, he’s made remarkable progress, his doctor said.

“Now, he’s a normal child again,” his mother said in Spanish. “I was scared the first time [we came here], but his health is more important than anything.”

About half of the patients who come to the Children’s National clinic are Central American migrants, Boughton said. The other half are a mixed group of migrants from African countries such as Ethiopia.

Over the past several months, the clinic has begun to advertise in schools throughout Montgomery County and in community clinics such as Mary’s Center.

According to the federal Department of Health and Human Services, black and Hispanic patients are almost twice as likely as whites to be diagnosed with diabetes by a doctor.

They are also more likely to die of the disease.

“How dare we not take care of people who need insulin to live?” Cogen said. “This clinic is our way of doing what we can, to do the best we can, to figure things out for our uninsured patients.”