Welcome to Health Reform Watch, Sarah Kliff’s regular look at how the Affordable Care Act is changing the American health-care system — and being changed by it. Sandhya Somashekhar is filling in while Sarah's away, and you can reach her with questions, comments and suggestions here. Check back every Monday, Wednesday and Friday afternoon for the latest edition, and read previous columns here.

Over on Capitol Hill, lawmakers are struggling to come to some sort of consensus on immigration reform, and it appears that health care is a big sticking point. Republicans especially are firm about one thing: no taxpayer funding for the newly legalized to get health insurance.

It isn't widely known, but taxpayers already do subsidize health care for illegal immigrants. That's been true for years and is likely to expand under Obamacare.

The program doesn't really have a name, but it is referred to colloquially as emergency Medicaid. It is reimbursement offered to hospitals to provide emergency and maternity care to people who, based on their income and other factors, would be eligible for regular Medicaid if only they weren't a) in the country illegally, or b) in the country legally but not lawful long enough to join Medicaid (five years).

That means, if you meet all the qualifications for Medicaid in your state except for your immigration status, you qualify for the program. And because about two dozen states are increasing eligibility for regular Medicaid under the health law, more people in those states will also be able to have their emergency services paid for under the program.

By emergency, we mean EMERGENCY -- sudden-onset conditions that threaten life or could cause serious impairment, according to the regulation. (The covered conditions for legal immigrants are a little broader). And it's not a perfect system; some hospitals bill the patient first and, if the patient can't pay, turn to this program as a way to recoup their costs.

In 2011, the last year for which CMS data are available, the federal government paid out $1.3 billion under the program, on top of the hundreds of millions of dollars states paid out to hospitals (If you click on that link, go to the FY 2002-2011 financial management report and scroll down to line 10,659). A large percentage of that is labor and delivery, because so many of those who qualify are pregnant women. And of course, all the little resulting babies will be U.S. citizens.

There are a lot of reasons from a policy perspective for such a program to exist, said Diane Rowland, executive vice president for the nonpartisan Kaiser Family Foundation -- to prevent the spread of communicable diseases, and to ensure a generally healthy workforce to contribute to the economy, for instance.

"Finally, from the perspective of our health-care system, when people show up and they’re sick, the health-care system is obligated to take care of them," she said.

For another look at this issue, Phil Galewitz at Kaiser Health News did a piece on emergency Medicaid earlier this year.

KLIFF NOTES: Top health policy reads from around the Web.

Arizona legislature votes to expand Medicaid. "Arizona Gov. Jan Brewer muscled her way to victory in her crusade for Medicaid expansion Thursday, outmaneuvering conservative opposition to push through a key piece of President Barack Obama’s agenda." Jason Milliman and Kyle Cheney in Politico

Health law's lack of clarity on what it means for companies to provide "affordable" insurance could have repercussions. "Because of a wrinkle in the law, companies can meet their legal obligations by offering policies that would be too expensive for many low-wage workers.  For the employee, it’s like a mirage — attractive but out of reach." The Associated Press

Florida gets its Medicaid waiver. "Friday’s announcement was a victory for Gov. Rick Scott and Republican lawmakers who approved the proposal to move to statewide Medicaid managed care in 2011, amid controversy about whether the changes would best serve the needs of low-income Floridians." Jim Saunders in The News Service of Florida, via Kaiser Health News