NASHVILLE — Jacqueline Acevedo is a shy seventh grader who spends long hours at the Baptist church where her father serves as a volunteer pastor after earning a scant wage from his day job selling bread.

Gabriel Garcia is a talkative 10-year-old whose mother is a chemist but drives for Uber and whose father squeezes grocery costs by posting receipts on the refrigerator door.

Although the families differ greatly — Jacqueline’s parents are unauthorized Salvadoran immigrants with little education, while Gabriel’s left rewarding professions in Venezuela and won legal asylum in the United States — the Nashville-area youths have two things in common.

They are children of poor immigrants. And their families have less access to aid than natives with the same incomes.

Children of immigrants, the fastest-growing group of American youths, have poverty rates more than twice those of other children. That is partly because their families earn less than native workers, but also because they face more barriers to government support. The barriers are largest for children of undocumented immigrants, but families of legal immigrants face obstacles, too.

More than 40 percent of the country’s poor children are children of immigrants. While most are American citizens, about half have an undocumented parent, which bars the whole household from some government benefits. For parents who immigrated legally, obstacles to aid include waiting periods, language barriers and lack of program knowledge.

Were Jacqueline’s parents native-born, the family could receive $12,000 in tax credits and food subsidies. Being undocumented bars them from three-quarters of that support, leaving Jacqueline — an American child, Tennessee born and raised — thousands of dollars below the poverty line.

As legal immigrants who do not speak English, Mr. Garcia and his wife face different impediments. While they qualify for food stamps, they only recently learned of the program and are unsure if it is proper to apply.

The question of immigrants’ access to aid has long generated sharp divisions, but the debate has grown more consequential as immigrant families account for a growing share of American children.

“It’s a very stupid investment decision to exclude or discourage these children from getting help,” said Dolores Acevedo-Garcia, who runs a research group at Brandeis University called diversitydatakids.org. “About 90 percent of these children are U.S. citizens, and even those who aren’t are likely to stay here until adulthood. They’ll be with us as our future workers, neighbors and taxpayers.”

Since most immigrants are Latino or Asian, barriers to aid may also deepen racial and ethnic divides.

Those who support limits on government aid say the country has always expected immigrants to practice self-reliance. They call it unfair to tax Americans for imported poverty, especially when immigrants come illegally, and warn that more welfare could encourage more unauthorized entries. If poverty among immigrants is a problem, they say, the solution is to admit fewer needy immigrants.

Even with the restrictions, immigrants get welfare at elevated rates because they are disproportionately poor.

“The more welfare that immigrants use, the more difficult it becomes to afford anti-poverty initiatives for the native-born,” said Steven A. Camarota of the Center for Immigration Studies, a group that seeks to sharply reduce immigration.

In Nashville, a growing immigration hub, Jacqueline Acevedo’s father, Julio, confronts child poverty as parent and pastor. His modest church, which meets in a converted house, acts as a safety net of last resort, offering food, clothing and testaments to God’s love to newcomers from across Latin America. Many, like him, are undocumented.

More interested in scripture than politics, Mr. Acevedo, 47, is reluctant to complain about restrictions on immigrant aid. “I’m very, very, grateful to God and to this country because I’m aware that I’m better off here,” he said.

But when he talked of seeing children in church without enough to eat, his voice caught.

“I know what it’s like to be hungry,” he said.

Poverty is all Mr. Acevedo has known. He was born just before the Salvadoran civil war, and was 4 when his father died of an undiagnosed disease. Soldiers burned the family home, leaving his mother a homeless widow with more children than she could feed. He joined the army at 16 but left it a dozen years later to avoid a mission in Iraq.

By then, his wife, Rosa, had joined a brother in Nashville and found work as a cook. Mr. Acevedo followed, leaving their sons, 2 and 4, with relatives. Though he planned to return in a few years, the separation lasted two decades, as the Acevedos decided the best way to help their sons was to send money for their education. The family reunited only a few weeks ago when the brothers, weary of the separation, made their own unauthorized journey to Tennessee.

The birth of Jacqueline, 12 years ago, further rooted the Acevedos in the United States. “She is a gift of God,” Mr. Acevedo said.

Like all children, she is also an expense. Working together, the Acevedos earned about $26,000 a year during the pandemic selling bread to grocery stores, and Mr. Acevedo spends Fridays on volunteer church work, to thank God for saving him from war and alcoholism. Since Jacqueline is a citizen, they receive the child tax credit, and she receives free school meals and Medicaid.

Native-born families and most legal immigrants could get much more: roughly $9,300 in food stamps and the earned-income tax credit, which undocumented immigrants cannot collect. (Though Jacqueline is eligible for a prorated food stamp benefit, the family is unaware of the policy.) The additional aid would lift her above the government poverty line.

Immigrants compensate for barriers to aid in part by working more.

Mr. Acevedo’s assistant pastor and half brother, Fredi Hernandez, works in a factory. Mr. Hernandez’s wife cleans, and their two daughters, 18 and 21, mix work and school and give the parents most of their pay. (The adults are undocumented, and a young son is a citizen.)

“It’s very important we all work,” Mr. Hernandez said.

The pooled earnings lift the family above the poverty line, but they struggled when they arrived seven years ago. Fleeing gang violence that killed a friend, one daughter developed temporary facial paralysis, grew depressed and cut herself, but the family could not afford medical care.

“We felt powerless,” Mr. Hernandez said. “I’m not complaining — it’s just a fact. We understand we come from a different country.”

Inside the church, one family’s hardships have left an especially vivid impression. Luz Canales and her husband, undocumented immigrants from Honduras, were living in a garage with five young children when they first came to church. Her husband fell ill and could not work. Ineligible for food stamps, though they received free school meals, the children arrived at services so hungry that Mr. Acevedo took them home to eat.

“Look, there’s one thing I want you to understand,” Mr. Acevedo said, referring to the limits on immigrant aid. “The fact that I’m not complaining doesn’t mean I don’t have my opinion that it’s unjust.”

Citing scriptural commands to seek justice, he said he was speaking out despite the risks to encourage compassion. “Sometimes we see each other’s struggles but feel indifference — there’s no love,” he said.

Fears that poor immigrants will prove costly are old as the country itself. But only since the Great Society initiatives of the 1960s, which expanded immigration and aid, has mass migration coincided with a welfare state. Congress in the 1970s barred undocumented immigrants from most programs, and in 1996 it reduced access for many legal immigrants, too.

Most adult legal immigrants must wait five years to get public aid, unless they are elderly. While noncitizen children typically qualify without a wait, the adult restrictions reduce the family’s income.

Program by program, immigrant eligibility varies greatly, with no obvious logic. Undocumented parents with citizen children get one cash subsidy (the child tax credit) but not another (the earned-income tax credit). Undocumented children receive school meals but not food stamps.

Nearly 20 million children in the United States have an immigrant parent, and since the 1970s their share of the child population has quadrupled to 27 percent. Fully 44 percent of poor children have an immigrant parent, according to research by Ms. Acevedo-Garcia, the Urban Institute, and UnidosUS, a Latino advocacy group. Nearly a fifth of poor children have an undocumented parent.

“There’s no way to reduce child poverty without including immigrant kids,” said Brayan Rosa-Rodriguez, a UnidosUS analyst.

Robert Rector of the conservative Heritage Foundation, said the country should admit fewer low-skilled immigrants, both legal and undocumented. About 11 million undocumented immigrants live in the United States, and roughly half of the adults lack high school degrees.

“It’s inevitable that large numbers of them are going to be poor,” he said. “The solution is to stop importing poverty.”

The Trump administration tried to penalize welfare use among legal immigrants by counting it against them if they sought permanent residency. Although courts blocked the so-called public charge rule after several months, critics say the publicity has left some families afraid to seek aid.

But sympathies shifted during the coronavirus pandemic when undocumented immigrants won new appreciation as “essential workers.” After denying them stimulus checks, Congress passed a bill making them eligible, which President Donald J. Trump signed.

“That was a teachable moment — it showed the costs of leaving large numbers of people unattended,” said Michael Fix of the Migration Policy Institute, who, in a study with Jeanne Batalova, found that poverty in noncitizen families plummeted as a result of the aid.

While child poverty has fallen in recent decades for both immigrant and native households, large disparities remain. According to Ms. Acevedo-Garcia and her colleagues, the prepandemic poverty rate was 9.3 percent for children of natives, 20.1 percent for children of immigrants, and 31.1 for American children in undocumented families.

Even when eligible for aid, immigrants are less likely to receive it. “There are language barriers, knowledge barriers, fear issues, trust,” said Tara Lentz, co-director of Conexion Americas, a Nashville group named for the connections it helps immigrants make.

Nationwide, about 82 percent of eligible people get food stamps, but only 60 percent of eligible noncitizens, government data shows. Immigrant families eligible for the earned-income tax credit are 28 percent less likely to report getting it, according to a recent study in the journal Health Affairs by Dana Thomson and three co-authors.

In a comprehensive study last year, Child Trends, a research group, found that in 2019 government aid cut child poverty by 47 percent in native families but only 39 percent among immigrants. Citing limits in the data, Ms. Thomson, a co-author, said the gap is likely larger.

“The people who most need the aid have the least access to it,” she said.

Public aid was the last thing that Jose Garcia and Yamile Yepez had in mind five years ago when they flew from Caracas to the United States. The prosperous couple were taking their 5-year-old, Gabriel, to Disney World, when they learned that intruders had broken in their house. In a country saturated with political violence, Mr. Garcia, a government computer engineer, had already survived a kidnapping. He considered the break-in a death threat.

“We left it all behind, everything,” he said, abandoning house, cars, and savings to seek asylum.

Suddenly poor, the couple spent two years pursuing legal protection, mostly without authorization to work. They did odd jobs, borrowed from family, and “only rarely” ate less to feed Gabriel. Ineligible for most aid while waiting, they were afraid to seek it anyway for fear it would harm their case. “I thought it might be illegal,” Mr. Garcia said.

Without health insurance, Ms. Yepez used expired birth control pills she had brought from Venezuela and learned to her distress that she was pregnant. A second son and legal papers arrived in close succession — she thanks God for each — but economic progress has been slowed by their lack of English.

Until recently, Mr. Garcia drove for Uber, with net earnings of $20,000 a year. Tax forms filed by a paid preparer show they also received about $11,000 in tax credits — benefits they do not understand — but that still leaves them well below the poverty line. They know little about other programs and are wary of government help.

“You have to work for what you want,” Mr. Garcia said. “I wouldn’t use it unless I really need it.”

Gabriel’s teacher recently suggested they apply for food stamps, the first they had heard of the program. They could likely collect about $7,500 a year but hesitate to apply, citing their belief in self-sufficiency and fear the aid would harm their legal status. (Under current law, it would not.)

Mr. Garcia recently found a job in a battery recycling plant at $15 an hour, a step up from Uber driving. With Ms. Yepez driving for Uber while the children are in school, their income may exceed the government poverty line this year — about $33,000 for a Nashville-area family of four. But she may never regain what she had in Venezuela, with a doctorate and a job in a pharmaceutical plant.

Told that children of immigrants are disproportionately poor, Mr. Garcia expressed no surprise.

“The immigrant experience is rough,” he said, adding with a hint of willed optimism: “You have to find ways to feel good about what you do have, knowing that things will get better over time.”