Millions still go without insurance if law passes

"Many people think that this health care law is going to cover everyone, and it's not," says Nicole Lamoureux, executive director of the Alexandria, Va.-based National Association of Free & Charitable Clinics, which represents about 1,200 clinics nationally.

To be sure, it's estimated that the Affordable Care Act would greatly increase the number of insured Americans. The law has a provision that requires most Americans to be insured or face a tax penalty. It also calls for an expansion of Medicaid, a government-funded program that covers the health care costs of low-income and disabled Americans. Additionally, starting in 2014, there will be tax credits to help middle-class Americans buy coverage.

The Supreme Court is expected to hand down a decision this month on whether to uphold the law completely or strike down parts or all of it. If it survives, about 93 percent of all non-elderly, legal U.S. residents will be covered by 2016. That's up from 82 percent this year.

Still, millions of illegal immigrants won't qualify for coverage. This population will account for roughly 26 percent of those who will remain uninsured, according to Urban Institute, a nonpartisan think tank.

And many legal U.S. residents will go without insurance, too. About 36 percent of the population that remains uninsured will qualify for Medicaid but won't sign up for various reasons. Others likely will make too much money to qualify for assistance but be unable to afford coverage.

Here's a look at some of the groups that will likely remain uninsured if the law survives:

ILLEGAL IMMIGRANTS

More than 11 million unauthorized immigrants live in the United States, according to the Pew Hispanic Center, a nonpartisan research center. That amounts to nearly 4 percent of the total population. But there are no provisions that address illegal immigrants in the health care law.

They won't be able to sign up for Medicaid. They won't be eligible for the tax credits to help buy coverage. And they won't be able to use online marketplaces that the government will set up in order for people to get coverage in a process that's similar to buying plane tickets on travel web sites. Those online exchanges, much like the tax credits, will require proof of citizenship.

"They will still need to find alternative ways to seek care because nothing in the law really expands coverage and affordable coverage options for undocumented immigrants," says Sonal Ambegaokar, a health policy attorney with the National Immigration Law Center in Los Angeles.

The topic is a politically divisive issue. On one side, there are people who say that the government should provide health care for all U.S. residents — legal or not. The other side contends that doing so could take valuable resources away from U.S. citizens.

"Because of the limited supply of health care, we're almost in a sociological triage," says Bob Dane, spokesman for the Federation for American Immigration Reform, a national group that calls for stricter immigration laws. "It begs the question, 'Who do we serve, who do we serve first and who is not entitled?'"

Researchers have found that immigrants tend to use the health care system less than legal residents. Illegal immigrants, in particular, tend to avoid using the health care system until they have to, favoring home remedies first or making cash payments to providers when they need care. That population also is younger, so it generally has fewer health care needs, says Timothy Waidmann, a researcher with Urban Institute.

The think tank, using federal government survey data, estimates that illegal immigrants accounted for an estimated $18 billion of the $1.4 trillion spent on health care in the United States in 2007. That adds up to less than 2 percent of total spending.

Some say excluding illegal immigrants from the overhaul will keep some legal residents uninsured, too. Ambegaokar, the Los Angeles attorney, points to parents who are illegal immigrants but have children who are legal citizens because they were born in the United States.

If the parents are not eligible, they may not know that their kids qualify. And in other instances, if one child is legal and the other is not, the parents may decide not to sign up either to avoid playing favorites.

"The goal is to enroll everybody who is eligible," Ambegaokar says. "But when you make systems complicated and require proof of ID, you're going to inevitably keep out people who should be in."