The health care reform law signed by President Barack Obama in 2010 and upheld by the U.S. Supreme Court last week will help enroll an estimated 30 million low-income and now-uninsured Americans in an affordable insurance program.
But even when it takes effect, there will still be millions of uninsured people here. Who are they?
Undocumented immigrants, mostly.
As the Congressional Research Service points out, "Unauthorized (illegal) immigrants are expressly exempted from the mandate to have health insurance and, as a result, cannot be penalized for noncompliance."
The Affordable Care Act bans those living in the United States illegally from receiving taxpayer subsidies or tax credits to purchase health insurance through the exchanges being set up by states. Undocumented immigrants, therefore, are expected to make up the largest segment of some 26 million people who will remain uninsured, and therefore left to seek treatment in emergency rooms.
The Pew Hispanic Center has said there are more than 11 million illegal immigrants living in the country. Many do not have insurance.
"Undocumented immigrants accounted for one in seven of the uninsured in 2007, up from one in eight in 1999. Since undocumented immigrants will not be eligible for public insurance or private coverage obtained through exchanges under the Affordable Care Act, they will eventually constitute a larger percentage of the uninsured population," wrote Urban Institute researchers Stephen Zuckerman, Timothy Waidmann and Emily Lawton.
So while the president and his party proclaim victory over the U.S. Supreme Court ruling, the issue of how best to handle the health care needs of the growing ranks of illegal immigrants remains unresolved.
Read more about how the Affordable Care Act handles illegal immigrants.