In Tucson, care for illegal immigrants includes a lot of emergency and trauma cases, including treating a 13-year-old boy who lost his legs after being run over by a train a few years ago. Illegal immigrants cost the University Medical Center about $5 million a year, or a quarter of the hospital's charitable care. Annual revenue is around $550 million.

No hospital executives interviewed blame their budget issues solely on immigrant care. The expense of treating undocumented workers at U.S. hospitals is growing along with the rising cost of caring for all the uninsured. (Uncompensated care rose 57 percent, to $34 billion, from 2000 to 2007, according to the American Hospital Association.) Nor did any say illegal immigrants should not be treated. On the contrary, even more care is needed.

"I will take care of them first and ask questions later," says David Green, CEO of El Centro Regional Medical Center in California. "My biggest concern is there is no reimbursement for taking care of all these souls from south of the border."

Green sees a lot of emergency-room cases, including Mexicans who break their bones sneaking across the border. Women come into the country to have babies. One Mexican woman crossed multiple times to deliver four babies at El Centro, Green says. As much as half of El Centro's more than $10 million a year in charitable care is spent on illegal immigrants, Green says. The hospital's revenue is about $100 million a year.

The cost of treating illegal immigrants in California emergency rooms is more than $1 billion a year, or about 10 percent of the $11 billion in free care the state's hospitals provide a year, says Jan Emerson, a California Hospital Association spokeswoman.

In 2004, Congress approved $1 billion over four years to help reimburse hospitals for care of illegal immigrants. California was the largest recipient of that government money, getting $72 million annually over four years. That program expired last year.

"It's clearly a drop in the bucket," Emerson says. But the symbolic gesture was an encouraging sign, she adds. "It was the first time the federal government acknowledged that it had a financial responsibility."

Hospital associations from California, Arizona, and Texas were joined by other groups in other states with large immigrant populations, including Florida, Illinois, New York, New Jersey, and South Carolina to lobby for the aid.

States mostly draw on emergency Medicaid funds to pay for the care. In 1996, the feds shifted more burden for covering immigrant health costs onto locals. That year, Congress passed a law requiring immigrants to wait five years after becoming citizens to apply for federal health benefits.

That's bad for a state like Texas, where a quarter of the population is uninsured, including many illegal residents. There are 1.6 million undocumented immigrants in Texas, or just less than 7 percent of the total population.

And local governments aren't going to see any help this year or next if health reform passes. Washington is steering clear of any immigration debate.

"The politics are real simple: It will not be addressed in context of health reform," says Ernie Schmid, senior director of policy analysis for the Texas Hospital Association.