Report: Number of uninsured falls by 5.4M under Obamacare

The number of adults in the United States without health insurance has fallen by about 5.4 million since the first quarter of 2013, according to a new report assessing the impact of the Affordable Care Act.

The Urban Institute found that in March 2014, the rate of adults between the age of 18 and 64 without health insurance had fallen to 15.2 percent.

That number was a 2.7 percent drop – representing about 5.4 million people – from the numbers in September of 2013, which is the month before open enrollment began for the much-debated heatlh care law.

President Obama announced earlier this week that 7.1 million people had signed up for coverage. And administration officials said that they were still determining how many enrollees were previously uninsured and whether enough younger, healthy people signed up to offset the costs of covering older, sicker consumers. 

Those markers will be important in ultimately determining the success of the controversial health care overhaul.

The Urban Institute report also found that states that implemented Medicaid expansion under the Affordable Care Act saw a larger decline of their uninsurance rate, which dropped four percentage points since September 2013, as compared to a 1.5 percentage point drop for those states that didn't expand Medicaid under the law.

House Republicans, meanwhile, launched a new attack on "Obamacare." They scheduled a vote Thursday to change the law's definition of full-time work from 30 hours a week to 40 hours a week. The result would be that fewer workers would get employer-sponsored health coverage. But the bill faces certain death in the Democrat-controlled Senate.

Republicans say the change would give relief to businesses that have to cover full-time workers or pay a fine. They seized on a recent report saying the law will lead workers to cut their hours or leave the workforce.

Al Jazeera and The Associated Press