http://thinkprogress.org/health/2015/03/23/3637685/obamacare-hospital-savings/
"The savings reflect a reduction in the so-called “uncompensated care” that hospitals provide to uninsured Americans, and are even greater than HHS officials predicted they would be at the beginning of this year.
Since people without insurance typically don’t have any means to cover their medical bills, the cost of their treatment ends up falling on the hospital itself. Therefore, as more people gain coverage, it become less expensive for hospitals to care for their patients. More than 16 million previously uninsured Americans have gotten covered under Obamacare, contributing to the biggest drop in the national uninsurance rate over the past four decades."
